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I have done everything and it still overheats in traffic
With AC on on any day that is above 85 degrees, my '86 Trans Am heats up going up a nearby mountain and sitting in stop and go traffic. I have a 350 TPI swap that replaced the factory 305 and I have updated the AC to R134a with the proper pressure switch adjustment. I'll outline everything I have done below, and all temperature readings are done with an IR thermometer unless otherwise specified. All of my emissions equipment is intact because this car is daily driven in Pennsylvania, so I need it to be able to pass emissions inspection.
What I've done:
50/50 Prestone Antifreeze/Water mix
180 stat with appropriate fan enable temps
New ACDelco water pump with the swap (~8000 miles ago) that I know is not cavitating or for a serpentine. It is the proper V-belt unit.
New Belts
New Hoses
4th gen LS1 fans on the stock radiator
Cold Case Aluminum Radiator and fan shroud
Burped the system MULTIPLE times, I am 99.99% certain that there are no air bubbles in the system.
Replaced 180 stat with high performance Mr Gasket 180 stat
Upgraded Cold Case fans from factory twin 120W to twin 180W from American Volt
Removed transmission cooler from stack
cleaned condenser and radiator fins
Things that I know:
When the AC is off it still gets to about 200 but is for the most part fine (still heats up going up the mountain, 3rd gear around 2100rpm at ~35-40mph
Temp is fine going down the highway
When idling in my driveway or garage with AC on and the hood OPEN, the temperature doesn't climb unless I hold the car at about 2000rpm
Idling with the hood closed or in stop and go traffic, temperature slowly creeps above 220 on the gauge, measured at the thermostat housing around 210
The fans turn on when they should
Timing is right where it should be
High side AC pressures tend to be higher than I would like
AC condenser surface idling in the garage with hood open sticks to right around 130-140 degrees
Turning on the heat drops the temperature like a rock
My theories (from most to least confident):
With the hood closed and not moving faster than 45mph, air is getting into the engine bay, heating up, and not getting out to make room for cool air. This theory is driven by the fact that the heater, which draws air from the dash vents by the wiper blades, drops the temps quickly and the radiator, which is much larger, does not, even with both fans on. How to remedy this without cutting holes in my freshly painted factory GTA/WS6 style hood, I don't know. I'm open to suggestions.
The 16psi radiator cap that ships with the Cold Case radiator is bad from the factory. The car doesn't bubble or anything when it gets hot, but the cap appears to be a little cheap, maybe a chineseium garbage part that's just bad.
The ACDelco water pump isn't moving enough water and I need to get a high flow pump from Tuff Stuff (what my dad put in his 67 Camaro with a 406 that cools fine) or similar.
Re: I have done everything and it still overheats in traffic
I don't think a high flow water pump is going to help.
A while ago, I was struggling with temperature issues and discovered my Miniram had a front water cross over that was too shallow, thereby preventing the thermostat from opening all the way. It was something I would have never considered had I not found it by accident during an internet search.
In the meantime, I tried LS fans, a Frostbite radiator, a Stewart high-flow pump, etc...
After I fixed the thermostat issue, the temperature problem got resolved. Just for kicks, I started reverting back to my original cooling system (one component at a time) and noticed zero difference in the end. The plastic tank aluminum radiator cooled just as well as the all aluminum Frostbite. The stock water pump cooled just as well as the Stewart, etc... And this is on a ~420 hp 383 with A/C as well.
Questions/comments
1.) how well is the fan shroud sealed to the radiator?
2.) how well is the radiator sealed to the radiator support?
3.) I understand that the front air dam is critical to 3rd gen cooling. Is that in place and intact?
4.) the hot air coming in through the radiator is free to go under the bottom of the car, so I don't think you necessarily have a "traffic jam" of air that's not letting air go through the radiator.
5.) How does the A/C perform in terms of vent temps? An airflow problem through the radiator would also probably also manifest as diminished A/C performance as well, since the condenser is right in front of it. If the answers to 1 and 2 are "very well", then that makes this consideration even more significant. A well performing A/C system would be indicative of air freely flowing through the condenser and radiator.
6.) I've heard of instances where these aftermarket aluminum radiators have the tubes inadvertently clogged/plugged from the factory. If so, that could explain why the heater vent appears to cool better than the radiator.
7.) How did you verify your ignition timing?
Something seems like it's off... For a relatively mild street small block, you really shouldn't need more than a factory style radiator and a stock water pump. Even in 95F+ weather with A/C on, my 383 with a 180F standard thermostat, it'll momentarily get between 195-200 going up a steep hill. But during normal during normal driving it stays at 190F around town and 180F cruising along on the freeway. The LS1 fans should also move roughly close to the airflow as my two-speed Taurus fan.
BTW, I know people will say "220 isn't a problem!!".... I had the same comments when I was chasing my thermostat issue. My response was always "I know that". I knew something was off and what I was attempting to do was get predictability out of the system. So yeah, I get what you're trying to accomplish here.
Re: I have done everything and it still overheats in traffic
sure seems the fans are the problem-check that the blades are installed correctly for pulling,all fans wiring is big enough to avoid voltage drop.I do not know anything about cold case or American volt fans-if these are similar to Ebay China fans,replace with Flex-a -lite,spal, etc.or good salvaged OEM fans.Often a high power fan placed close to the radiator without a shroud is effective because high velocity airstream strips away insulating boundry layer effects that can occur with lazy airflow.
Re: I have done everything and it still overheats in traffic
@ULTM8Z
1) Pretty well, it's flush and directly bolted to the radiator.
2) This one could be the problem, because not very well, but from what I can tell, it isn't any worse than the way the radiators seal from the factory, which they pretty much don't.
3) My air dam is in place and intact., but even if it weren't, as far as I can tell, I would be having issues on the highway and not I was sitting in traffic idling. @1989karr
4) That's the only thing I can think of with the car cooling better with the hood open.
5)The AC vent temps are fine, it works just like I would expect AC to work. Around 40-50 degrees on max cold according to my IR thermometer. Pretty close to what my dad's VintageAir system does in his 67.
6) Possibly but doubtful, Cold Case is generally a good brand from what I can tell.
7) I used a timing light in conjunction with plugging into the ECM to make sure that the commanded spark advance was the true spark advance.
I wholeheartedly agree that I shouldn't need more than this. Have you ever heard of the Edelbrock TPI base having an issue like that? I will say that it does sound like you had the exact same issue. I've seen so many people with much beefier engines on stock rads and 4th gen fans (just like what I had before the upgrades) that claim to never break 200 degrees, and even if 220 is totally normal, it shouldn't keep climbing with both fans on
Re: I have done everything and it still overheats in traffic
Originally Posted by 8t2 z-chev
sure seems the fans are the problem-check that the blades are installed correctly for pulling,all fans wiring is big enough to avoid voltage drop.I do not know anything about cold case or American volt fans-if these are similar to Ebay China fans,replace with Flex-a -lite,spal, etc.or good salvaged OEM fans.Often a high power fan placed close to the radiator without a shroud is effective because high velocity airstream strips away insulating boundry layer effects that can occur with lazy airflow.
They definitely pull air, considering I can stick a bag of hardware to the front of the condenser and it will stay there, and Cold Case is an American company based in Pennsylvania. And as I stated before, even the LS1 fans, which are a very common upgrade, did not pull as much air as the ones in the car do. They are almost identical to flex-a-lite, and Spal is ridiculously expensive.
Re: I have done everything and it still overheats in traffic
Originally Posted by TheMagikMan
@ULTM8Z
1) Pretty well, it's flush and directly bolted to the radiator.
2) This one could be the problem, because not very well, but from what I can tell, it isn't any worse than the way the radiators seal from the factory, which they pretty much don't.
3) My air dam is in place and intact., but even if it weren't, as far as I can tell, I would be having issues on the highway and not I was sitting in traffic idling. @1989karr
4) That's the only thing I can think of with the car cooling better with the hood open.
5)The AC vent temps are fine, it works just like I would expect AC to work. Around 40-50 degrees on max cold according to my IR thermometer. Pretty close to what my dad's VintageAir system does in his 67.
6) Possibly but doubtful, Cold Case is generally a good brand from what I can tell.
7) I used a timing light in conjunction with plugging into the ECM to make sure that the commanded spark advance was the true spark advance.
I wholeheartedly agree that I shouldn't need more than this. Have you ever heard of the Edelbrock TPI base having an issue like that? I will say that it does sound like you had the exact same issue. I've seen so many people with much beefier engines on stock rads and 4th gen fans (just like what I had before the upgrades) that claim to never break 200 degrees, and even if 220 is totally normal, it shouldn't keep climbing with both fans on
All you can do is measure the depth of the water passage where the thermostat sits and compare that to the fully opened height of the thermostat. That's what I had to do to confirm what I read about. Though I'm skeptical you have the same issue on the Edelbrock base. I can't imagine Edelbrock doing something that dumb.
On the timing, I'm assuming you ran a dial back timing light and validated the timing at higher than idle RPMs. What I've also done is to set all timing values to 20deg at all maps and conditions. Then used the dial back timing light to verify that I'm getting 20deg everywhere while reving the engine in the driveway. Basically I set the dial back to 20 then rev'd the engine by moving the throttle linkage while I held the light to the harmonic balancer... the TDC mark on the balancer stayed solidly on the 0 of the timing marker above the damper, telling me the actual timing matched what the ECM was commanding at all RPMs.
At this point though, I wouldn't rule anything out. I'd still try to inspect the radiator tubes as best as you can. If your airflow through the radiator is good, and you're saying that turning the heater on cause the temperature to drop precipitously, that seems to me like a coolant flow problem through your radiator. Also, double check the thermostat opening vs the TPI base...as unlikely as it may be.
Also, I'm assuming the inlet radiator hose has the spring in it, such that it's not collapsing when you rev the engine?
Re: I have done everything and it still overheats in traffic
I suppose I'll have to take it apart and measure it then, but I agree. I doubt that we have the same issue, edelbrock is usually a pretty great manufacturer, but who knows. I don't have a back timing light so I was using my timing marks on the balancer to verify, they go all the way up to 40 degrees. The hose does have proper spring in it. How do you suggest I check the coolant flow?
Re: I have done everything and it still overheats in traffic
Measure coolant flow? Not sure how you'd do that.
I do know that the heater is not on the same circuit as the radiator. It's essentially "in parallel" with your radiator. If the heater is essentially cooling better than the radiator....
Which is leading me to think there's something going on with coolant through your radiator. You might go on youtube and search on clogged/plugged radiators. They may have some tests you can perform.
Re: I have done everything and it still overheats in traffic
Originally Posted by ULTM8Z
Measure coolant flow? Not sure how you'd do that.
I do know that the heater is not on the same circuit as the radiator. It's essentially "in parallel" with your radiator. If the heater is essentially cooling better than the radiator....
Which is leading me to think there's something going on with coolant through your radiator. You might go on youtube and search on clogged/plugged radiators. They may have some tests you can perform.
Re: I have done everything and it still overheats in traffic
OK I just want to get something straight in case I've overlooked it.
When you say overheating do you mean coolant is violently flowing from your radiator into your coolant bottle, going way past the HOT line on the bottle and flowing out the vented cap on top and making all kinds car is overheating sounds.
Or do you mean the needle on the gauge in the dash is higher than you expect or would like to see it run?
Re: I have done everything and it still overheats in traffic
Originally Posted by Airwolfe
OK I just want to get something straight in case I've overlooked it.
When you say overheating do you mean coolant is violently flowing from your radiator into your coolant bottle, going way past the HOT line on the bottle and flowing out the vented cap on top and making all kinds car is overheating sounds.
Or do you mean the needle on the gauge in the dash is higher than you expect or would like to see it run?
It's just getting hotter than I would like, and I lost my last engine to an overheat so I'm not going to let it happen again. And I would like to be able to use my AC without worry (I daily drive the car and it's friggin hot out) especially considering my cooling system should be far more than adequate for my powertrain.
Re: I have done everything and it still overheats in traffic
Like I said, I know where he's coming from on this.
These temps obviously are not dangerous and the car is not "running hot" so to speak... (as the factory runs them this hot as a matter of course). And it's understood that the car will not always run at the thermostat temperature.
But the bottom line is you want the predictability of knowing how the car will behave in any weather condition. It's gotten to the point now for me that I don't feel like I have to monitor my temperature gauge in hot weather anymore because I know how the car runs... which is how it should be (I don't have to do that in my daily driver either).
Re: I have done everything and it still overheats in traffic
High volume water is not going to help U as all it does is move more coolant thru the rad and thus does not allow coolant to spend more time in the rad cooling.
Per the thermostat - place the t-stat in a pot of water, place a thermometer in the pot, but not touching the pot bottom & turn on the heat. T-stat usually is no open fully until close to 10* above opening temp.
Watch the thermom temp rise & note when the t-stat begins to open & when it is fully opens & record the temps.
Re: I have done everything and it still overheats in traffic
Was it posted anywhere, how hot it's actually getting? That is pretty important, and I don't see a number in the thread.....
I drive a steep mtn climb to work every day. I have a DeWitts Radiator and a properly maintained cooling system that generally works pretty great. However, if I drive this climb (~3000' over 6 miles), at 30 mph, my coolant temp will climb into numbers that "don't like". Up to 230° or so. I do this climb in 4th or 5th gear, RPMs generally 1500-2500 or so. Fans don't run b/c I'm going over 25 mph, but there isn't enough airflow to match the heat generated by the engine. B/c my car has an oil temp gauge, I've noticed that hi oil temps (which rise w/load and/or RPM) drives up the coolant temp. I feel that if I had an oil cooler and kept my oil temp down, under those heavier load conditions, then the coolant temp would also stay down. Do you have an external oil cooler? If you have an internal or no oil cooler, that oil puts it's heat into the cooling system...either in the radiator tank or though the block/heads.
Re: I have done everything and it still overheats in traffic
I still vote it's the fans. Everything else mechanical appears to have been covered. You could have had weak LS fans and these just seem better. Seeing if something sticks to the condenser is hardly a good verification of proper airflow through the condenser/radiator.
The $60 fans you are using claim 2964 CFM from a "14 amp" motor using factory installed 14awg wiring....I have some ocean front property here in Illinois I could sell you if you are interested.
Re: I have done everything and it still overheats in traffic
Earlier post indicates he is getting up to 210* in stop and go traffic. Not sure outside temps or humidity level. I think he meant A/C on for that too. I'm not convinced there is much more to do here.
Re: I have done everything and it still overheats in traffic
when you turn on your heat, the temp drops like a rock. hmmmmmmm....... Are you actually over heating? Or just getting hot? Over heating to me, means you have to pull off the side of the road and wait for car to cool down. that heater thing is interesting, it will usually help a little, but like a rock? have you flushed your system? maybe the water jackets are clogged?
when you are sitting in traffic, there is no air flow except fans. so it has to "boil" down to fans or water not moving thru the cooling passages correctly for some reason. sounds like you have ruled out the fans, so back to cooling passages......
BTW - my car runs cooler with a/c running. this is because both fans are running.
Last edited by LiquidBlue; 08-06-2024 at 12:28 PM.
Re: I have done everything and it still overheats in traffic
Originally Posted by Aaron R.
Earlier post indicates he is getting up to 210* in stop and go traffic. Not sure outside temps or humidity level. I think he meant A/C on for that too. I'm not convinced there is much more to do here.
Thanks for posting that. I totally agree. 210° in summer/AC on is well w/in the range that OEM's and I would consider to be totally fine.
Re: I have done everything and it still overheats in traffic
In stop and go traffic with the a/c running, mine will usually get up to 220, or right in the center of the gauge. When I start moving it'll drop back down to 195-200ish.
I do have the 215 degree fan switch for the Grand National.
Re: I have done everything and it still overheats in traffic
Originally Posted by LiquidBlue
when you turn on your heat, the temp drops like a rock. hmmmmmmm....... Are you actually over heating? Or just getting hot? Over heating to me, means you have to pull off the side of the road and wait for car to cool down. that heater thing is interesting, it will usually help a little, but like a rock? have you flushed your system? maybe the water jackets are clogged?
when you are sitting in traffic, there is no air flow except fans. so it has to "boil" down to fans or water not moving thru the cooling passages correctly for some reason. sounds like you have ruled out the fans, so back to cooling passages......
BTW - my car runs cooler with a/c running. this is because both fans are running.
Temps dropping with heat turned on points at one or two things or both things combined.
1: Lack of airflow through Condenser/Radiator.
2: A/C issues causing excessive heat build up in condenser overwhelming the radiator. (Improving #1 could help this)
That being said I agree with you on the overheating definition. Overheating is coolant boiling over. Getting hot (ter) is not necessarily overheating. Furthermore as stated previously the factory gauges are known to have inaccuracies. Best to verify what the CTS is telling the ECM as well.
I don't agree with the part of him having the fans ruled out. I highly suspect them as being inadequate. Plenty of other people not having these issues using known good fan setups, including single fan setups.
Last edited by dabomb6608; 08-06-2024 at 01:47 PM.
Re: I have done everything and it still overheats in traffic
Originally Posted by 80schild
In stop and go traffic with the a/c running, mine will usually get up to 220, or right in the center of the gauge. When I start moving it'll drop back down to 195-200ish.
I do have the 215 degree fan switch for the Grand National.
same for me..
I also have LS fans like OP so when AC is on the temps tend to stay a bit lower as the fans are always running unless they cycle.
@ OP maybe thats normal operation? The gauges are notoriously inaccurate though. so yours might be higher than what it should be?
Re: I have done everything and it still overheats in traffic
Unfortunately my LS fans were not used from a yard. I bought them brand new off RockAuto and verified amperage draw. When I swapped those in I switched all the fan wiring to 10 gauge, so the current fans aren't on the factory 14awg wiring anymore, and neither were the LS fans. They should move more than enough air, especially considering that Cold Case is generally a damn good manufacturer, and put in fans with weaker motors from the exact same factory that the American Volt fans came out of.
Re: I have done everything and it still overheats in traffic
Originally Posted by TheMagikMan
Unfortunately my LS fans were not used from a yard. I bought them brand new off RockAuto and verified amperage draw. When I swapped those in I switched all the fan wiring to 10 gauge, so the current fans aren't on the factory 14awg wiring anymore, and neither were the LS fans. They should move more than enough air, especially considering that Cold Case is generally a damn good manufacturer, and put in fans with weaker motors from the exact same factory that the American Volt fans came out of.
Did your car come with Dual fans from the factory? Also, are you still using that operational system?
The older dual fan operation is a little odd... only one fan for ac and primary cooling...., the second comes on with the temp sensor in the head grounds and its a pretty high temp....
Re: I have done everything and it still overheats in traffic
Originally Posted by 1989karr
same for me..
I also have LS fans like OP so when AC is on the temps tend to stay a bit lower as the fans are always running unless they cycle.
@ OP maybe thats normal operation? The gauges are notoriously inaccurate though. so yours might be higher than what it should be?
Generally I would agree, and I am working on getting a second temperature gauge in, so I just ordered one. But I have also been using an IR thermometer to verify temps. Yesterday I got it to about 215* at the thermostat housing just sitting with the AC on in the driveway, which was about 230* indicated on the factory gauge. The issue being that even at 215 with both fans running, it was still creeping up in temps.
Re: I have done everything and it still overheats in traffic
Originally Posted by 1989karr
Did your car come with Dual fans from the factory? Also, are you still using that operational system?
The older dual fan operation is a little odd... only one fan for ac and primary cooling...., the second comes on with the temp sensor in the head grounds and its a pretty high temp....
I wired mine to both come on at the same time.
My car did not come with dual fans from the factory, just a single without a shroud, so I have the computer controlling the primary fan and the secondary fan on a temperature switch set to come on at 200* and off at 185*. The computer switches the primary on at 190 and off at 185.
Re: I have done everything and it still overheats in traffic
Originally Posted by 80schild
What about rust? Could some of your coolant passages in the engine be restricted due to rust?
I would doubt it, the engine only has 8000 miles on it and was hot tanked when it was built, and the radiator was steam cleaned and pressure tested as well, and all the hoses were replaced.
Re: I have done everything and it still overheats in traffic
Originally Posted by TheMagikMan
Unfortunately my LS fans were not used from a yard. I bought them brand new off RockAuto and verified amperage draw. When I swapped those in I switched all the fan wiring to 10 gauge, so the current fans aren't on the factory 14awg wiring anymore, and neither were the LS fans. They should move more than enough air, especially considering that Cold Case is generally a damn good manufacturer, and put in fans with weaker motors from the exact same factory that the American Volt fans came out of.
None of that really matters if all the symptoms still point to it being an airflow problem. Just because a manufacture gets away with weak fans on other vehicles doesn't mean they will work on 3rd gen Firebirds. Which arguably are among the most demanding/tasked cooling requirements due to lack of airflow. Compared to a vast majority of vehicles which have significantly better aerodynamic airflow through the cooling system.
The absolute bottom line here is if your car maintains cooler temps going down the highway compared to while in town/slower speeds...you need more airflow from the fans.
If you have a problem with your car getting to higher temps while in town...you need more airflow from the fans.
Re: I have done everything and it still overheats in traffic
More airflow yes, from the fans? Not necessarily. I need to find all the places that heat can escape as it's rising and make sure that I don't have anything blocking it, like the back corners of the hood. Spending a fortune on better fans when the same kind of fans is perfectly adequate for others with larger engines at lower temperatures is one solution, but brute force isn't always the way to go about it. Especially considering that I just graduated college, have very little money to throw at the problem, and need most of it for gas to power the car to interviews. There's a different underlying issue and I'm done throwing parts at it.
Re: I have done everything and it still overheats in traffic
I'm not sure it's an airflow problem (at least entirely an airflow problem).
He's getting up to 200F with A/C off, going 45 mph (albeit up a hill). On my car, with A/C off, 180 T-stat, it'll never go above 185F even in 90F+ weather, uphill, downhill, straight line, etc...
I do know that when I had my thermostat issue (which was a coolant flow problem), I had similar symptoms though.
Re: I have done everything and it still overheats in traffic
Okay, to kind of coalesce my two threads, I'll make another post in this one because it's more related to the issue. At first in the other one, I believe @dabomb6608 mentioned that I should have a lot of air coming out under the car on the driver's side. I do NOT have this airflow with both fans on. However, I do have quite a lot coming out the passenger side. When I opened the hood to investigate, it seems that my airflow is stagnating on the driver's side right behind the AC compressor. I have provided an image of it so that you can see where I'm talking about below. In front of the compressor, air is flowing like crazy out the back of the fan, and the air doesn't stagnate anywhere on the passenger side in the engine bay. There's not a whole lot of room for airflow in this engine bay, so I'm wondering if there's something I'm missing here. I don't believe I have ever felt the wind out the driver's side as described, not even from my last car (92 Camaro RS bone stock). I am considering a Four Seasons 1993 Taurus Fan for a 3.8L V6, But I am uncertain that I'll have the clearance for it or if it will even be better than these fans, or if I have some other underlying body issue that I am unable to trace that's blocking airflow and creating a high pressure environment under the hood. I will say that when I had the hood open 10 minutes ago, the temperature never even broke 180 until I shut the hood according to the laptop I had plugged in in the passenger seat. I think this is because I have a high flow thermostat in the car so even when it isn't open I get some coolant flow. @ULTM8Z on the other hand, I don't think the thermostat is the problem or any clearance issues like you had, because when I think about it, I didn't put this Edelbrock intake on until about a month ago, and I was still having the problem on the bone stock intake base, which I KNOW had enough clearance for the thermostat. I'm not really 100% sure where to go from here, and I apologize for being curt earlier to dabomb, I just graduated with a mechanical engineering degree and I'm probably overthinking things related to air pressure and whatnot.
Re: I have done everything and it still overheats in traffic
It's pulling air through the radiator into the engine bay as it should. By back I mean towards the back of the car. Fair enough, just ruling out that t stat issue completely.
Re: I have done everything and it still overheats in traffic
Originally Posted by TheMagikMan
Well I been thinking about asking you this question for a few days now. But sometimes I don't like to ask a bunch of questions because I feel like people might take it the wrong way and think I'm personally questioning them and get insulted by it. Kind of like "How dare you ask me such a simple thing, Do you take me for an idiot?"
This picture is worth a thousand words. It tells me everything I need to know.
As Eric O of South Main Auto would say... "There's you're problem lady!"
I'm sure you have been trying to figure this out for a while now. So waiting another hour ain't going to hurt anything. I'll give my theory as to your cooling problem an hour from now. Give some time for the viewers at home to play along and comment as to what they think the problem is. The answer is in the picture.
Last edited by Airwolfe; 08-06-2024 at 06:58 PM.
Reason: Spelling
Re: I have done everything and it still overheats in traffic
I have to mention,..... that when I had my single fan and non serp setup like yours on my 87, I believe most of the air flow came out on the passenger side now that I think of it.... I suspect its because the ac compressor, power steering pump and big brackets and what not were creating more "blockage" for the air to pass.... since I switched to a serp setup, I have more air flow (as I mentioned on the other thread) on the driver side and there is a TON more space due to the compressor being relocated to the passenger
its not a super fair comparison though because now I have the serp setup but I never ran it with the single fan..I only had it with the Ls1 fans... but there IS a lot more space for air to pass for what its worth.
I know a lot of air comes up now between the ac compressor and the intake snorkel when the passenger side fan is on. im not sure how much actualyl comes out the passenger side as i never really checked
Re: I have done everything and it still overheats in traffic
If your theory is the top shroud on the radiator, I normally have foam blocks to seal that gap, just not presently. But I hope it's something else and that you're right
Re: I have done everything and it still overheats in traffic
Originally Posted by ULTM8Z
I'm curious what that thing is in your upper radiator hose...
Oh that's an in line housing for the temperature switch for the secondary fan so I don't have to drain it out the head if I want to replace it. It's grounded to the chassis via a wire so that the switch works.
Re: I have done everything and it still overheats in traffic
Originally Posted by ULTM8Z
What's the inner diameter of that thing relative to your radiator hose?
Not much smaller, the inner diameter is bigger than the thermostat housing inner diameter, and I was having the same issue prior to putting it in with a different fan switch, so I don't believe that to be the issue.
Re: I have done everything and it still overheats in traffic
Well yes my theory does have to do with the gap between the radiator and the core support. But not just that gap. There is a huge gap on the sides too.
My Firebird has foam seals between the core support and condenser, the condenser sits very close to my radiator with almost no gap. Air can only flow from the opening in the core support through the condenser and radiator with none escaping around the sides or between the condenser and radiator.
Try boxing the in radiator to the core support so that no air can escape on the top, bottom, and sides. As an experiment try using some cardboard and duct tape and box it all in so the airflow has no choice but to go through the condenser and radiator. Also if you have removed your hood to cowl seal replace it.
Re: I have done everything and it still overheats in traffic
I'm posting my reply to your other thread here too.
The under hood insulation pad is there to protect the paint on the hood from the oven under the hood trying to cook it and to absorb some of the under hood noise making the car quieter.
The rear hood to cowl seal helps to cool the car when driving down the road at speeds above about 35 MPH. It also prevents hot under hood air from being drawn into the HVAC intakes on the cowl at lower speeds or sitting still.
At low speeds and sitting still removing the hood to cowl seal will allow hot under hood air to escape and the engine can run cooler but as the speed increases to about 35 MPH the windshield to hood interface at the cowl becomes a high pressure area and it will force airflow backwards into the engine compartment. This will cause dead air in the engine compartment and the engine can run hotter at speed or overheat.
Re: I have done everything and it still overheats in traffic
Originally Posted by 72buickgs
High volume water is not going to help U as all it does is move more coolant thru the rad and thus does not allow coolant to spend more time in the rad cooling.
That's actually a myth. The coolant does not need "more time" in the radiator to exchange heat, and the more time it spends in the radiator, the more time the coolant in the block is getting hotter and hotter. The disadvantage of coolant flowing too quickly is that it can result in cavitation and aeration, both of which inhibit heat exchange...
Re: I have done everything and it still overheats in traffic
Originally Posted by Airwolfe
Well yes my theory does have to do with the gap between the radiator and the core support. But not just that gap. There is a huge gap on the sides too.
My Firebird has foam seals between the core support and condenser, the condenser sits very close to my radiator with almost no gap. Air can only flow from the opening in the core support through the condenser and radiator with none escaping around the sides or between the condenser and radiator.
Try boxing the in radiator to the core support so that no air can escape on the top, bottom, and sides. As an experiment try using some cardboard and duct tape and box it all in so the airflow has no choice but to go through the condenser and radiator. Also if you have removed your hood to cowl seal replace it.
Okay, so I remade my foam blocks to the sides and top, and it's all sealed off now. I do wonder as to how this will help with stationary cooling, maybe it just means that the hot air in the engine bay isn't recirculating into the radiator and will help some? I do hope you're right and this helps quite a bit, as from a physics standpoint all of your other comments are sound. This solution seems to me like it would be better suited to helping highway cooling moreso than stationary, but I like the thinking. The other thing that I'm thinking about is that the fans I have don't have very straight or broad fins, and therefore probably aren't great for static pressure air movement like many other radiator fans are (for example: LS1 fans have straight blades which have higher static pressure stall, also generally true with lower count but broader curved blades). This could mean that if I am building up a fairly large amount of pressure in the engine bay, which was likely designed into the cars to keep the stock engines pretty hot for maximum efficiency, the American Volt fan blade design just isn't moving enough air as opposed to say these two fans from Spal (which on spal's website actually draw the same amount of power as the american volt fans do ~14A settled at speed). Can someone fact check that line of thinking? The Spal fans look like they have appropriate mounting holes for my current fan shroud, but cost more than 3 of the american volt fans for one unit.
Re: I have done everything and it still overheats in traffic
Hopefully it will help some.
That radiator seem to be huge. Is that the Cold Case LMP590A for 3rd gen Camaro and Firebird? Will it not fit into the car using the factory upper and lower rubber mounts and upper fan shroud?
Re: I have done everything and it still overheats in traffic
Originally Posted by Airwolfe
Hopefully it will help some.
That radiator seem to be huge. Is that the Cold Case LMP590A for 3rd gen Camaro and Firebird? Will it not fit into the car using the factory upper and lower rubber mounts and upper fan shroud?
That is the unit. It won't fit in the factory shroud and mounts, I had to cut the lower rubber mounts and put in supplemental ones for vibration reduction. As for the upper mount, it's not even close to being the right size. In order to install the fan shroud I actually had to delete my power steering cooling loop so it would fit between the core support and the steering box.
08-05-2024, 02:30 PM
