sheltonwaz28

my car slowly heats up until its around 250 then somtimes go up to 260 and back down to 250, for a while there my guage was jumping around a little bit but now it stays pretty steady. the water is not boiling or steaming out or anything and once it gets up to that temp it wont go down until i let the car cool for a half hour or so. it will stay that way at a stop or going 70 down the freeway. at first i thought i had to much coolant and not enough water so i drained it and put 50/50 mix in and made sure there was no air bubbles. next i took out the thermostat all together and replaced the coolant temperature sending unit. my water pump is in good shape, you can see coolant flowing through the radiator fine and when i step on the gas the bottom radiator hose closes a little but not much. ive also noticed that my fan doesnt come on until the guage is at about 255 so im thinking possibly a faulty guage. next on my list to do is replace the temperature sensor, im running out of ideas, any help would be good.

CaptPicardsZ28

BINGO!! Your fan doesnt come on until 255*

sheltonwaz28

i figured it out... it was a faulty guage, i went and bought a after market temp guage from a local parts store and it doesnt get any higher than 220, still a little hot for my taste but it is better than 260 any body know what a 305 tpi is supposed to run at?

CaptPicardsZ28

Around 220-240 I believe

xlwhellraiser

iTrader: (1)

305's "optimal" temp should be around 180*, however the cars from the factory are made to run about 220-190*. The 305's with one fan are especially prone to higher heat. However a clear radiator, 180 stat, and new fan motor along water wetter should keep you under 210.
Good luck

USA_Rally

your not gonna find many thirdgen 305's runnin at 180 that's for sure. 220 is about average for our cars, they just have a crappy cooling system. you can spend some $$$ and get it down to 180, but stock, 220 is good.

LO3BIRD

My wife's 305 Firebird is totally stock, 120Kmiles, I only put a 160 stat and reprogrammed the ECM's EPROM. And I wired the fan to stay on always (I know this sucks some amps and lowers fan life). But the e-fan has been running for years like this and they only cost $22 to replace.

Her temps are 160 all the time (new e-gauge) in sunny South FL. MAYBE 180 on a hot day with A/C on. Her car moves too, stays neck and neck with my brother's 5.0 stang. I think Firebirds do better, my Camaro sucks on cooling, but it doesn't really have anything stock on it. Both cars have the air-dams fairly busted up...

If you have a serp belt, make sure you have a serp pump (i.e. pull the top hose off and see what comes out).

USA_Rally

ya, mine is constantly creeping up to 260 on hot days. i'm going to have to wire the fan to stay on constantly as well. that really sux, i wish i could figure something else out.

BigBadLou

iTrader: (3)

You can install a 180deg thermo switch and wire it up to the fans, along with a wire from the A/C clutch (through a diode). That's what I did on my truck (I actually used an adjustable thermo switch) and I have no problems cooling. I also went crazy and made myself a speed switch that turns off the fans when speed exceeds 40mph (which guarantees enough flow through the radiator).
I've towed with this setup a few times already in the blistering TX heat and haven't had any problems.

Hope this helps.
Lou

Jim Berry

Ditto, 220 degrees. Even with A/C on in this hot TX weather.

bobsroc

I have basically the same setup as LO3bird in my 1987 IROCZ and it runs 160ish all day, everyday, with no problems. Everyone complains of high temps on stock setups, NO one will disagree. To keep your motor cool,rewire fan so it is on with ignition, put a lower temp thermostat in it (160*), make sure your water pump is up to snuff,flush the radiator, but a good mix in the radiator, and enjoy your car. GM set these cars up to run hot for emmissions reasons, which is bad one way and good in another. With all their **** poor engineering for emmissions they have left lots of room for improvement for us who could care less about emmissions. Rip it off, plug it, port it, siamese it, spend cash generating some air flow and WOW, you have a car that is actually fun to drive.....Peace yah..........

xlwhellraiser

iTrader: (1)

Well, most V8's are best running at 180. 160 is ok, and its really close to the mark of the close and open loop temp. 170 is ideal for both winter and summer. In a new working cooling system, with a functioning air dam, the temp should not reach over 210. This is still way hot, but the temp. should be around that area. Now, almost all firebirds and camaros's guages are crap by now, and installing a new guage is the way to go. I have a 180 thermo, but my guage shows that it opens up at 225 which is baloney. So I am in the process of installing a new guage tomorow.
Good luck. Hope this helps.

f-crazy

iTrader: (-1)

you want the motor/water temp at 220 or so...and by lowering the operating temp the the motor itself, emissions gas mileage is affected....the incoming AIR is what you want as cool as possible...

relocate the IAT sensor into the air duct and feel how much crisper throttle response has become becasue the air in the intake duct hasnt been heat soaked by the oil under the intake...

leave the thermo at stock temp, and relocate the IAT if you want more "power"

screaminformula

i really hope you aren't driving it at 250-260. that is ENTIRELY TOO HOT for these motors...you will end up losing a head gasket or seizing your engine...

Josh

Cadillac

Now I'm worried about the engine temp. Granted I'm using the stock temperature gauge but the needle for temp stays almost straight up all the time. Since my driving is exclusively restricted to stop and go city driving, I never get a steady stream of fresh air to the radiator.

I'm still all totally stock .

Anybody have any strong opinions one way or the other with WATER WETTER?

~C

xlwhellraiser

iTrader: (1)

I used water wetter and it helped maybe first two days. I did not have an air dam, and i just replaced my water pump. So, I ran about 180 the whole time with water wetter in the system. I would heat up after about 40 min. in stop and go traffic at 90 degree day. So the water wetter helped a bit. however, two days later, no avail. Water wetter was not working anymore and I got to 230. So, I went ahead and bought an air dam. Now I am running about 180-200. No matter how hot the day is. If I were to put in 170 thermo I would prbably run even cooler.
The biggest thing that changed the way my car operates was the water pump. I bought a cast iron bosch high flow ccw water pump and it works wonders. it was only 50 bucks and it gets the car cool, unlike some other pumps ( id rather say no names). It might be heavier, but hey it does the job. The heating helped my cars overall speed and quickness as well. When its cooler it goes faster. For example I beat this v6 supercharged Nissan. Makes about 245 torque. I was running at about 180, so he floors his car of the start and I am in third starting out. I go half way on my pedal and I am catching up. You can hear his car working hard, so i catch up, and maintain the same speed with him. I could have easily beaten him, but I found it more interesting to follow him. He than speeds up ( I am thinking all the way, by the way his car sounded). He cuts infront of me, so I shift into overdrive, floor it and fly by him. I look at my temp guage, and I am running bout 190. So, a new water pump with the dam will do wonders. Try it.

scott07422

my temp stays 220 but goes to 245 up hills but then goes back down to 220 you think that since i have a bra on the front that might kept it hot any help on this

USA_Rally

have u installed a secondary temp guage? like they said, our stock temp guages have a mind of their own.

scott07422

no secondary temp guage? i no one thing when the temp goes in the red line i stop and look at the hoses and they look good and nothing is overheating but still watching it go to red line makes you scared i no i have 3 sensor now i have to find the on the engine

bobsroc

Something else to consider here is how is your fuel delivery doing?? A motor running on the lean side will cause an over temp situation. Something to look into, Maybe.

Sickness91Z28

iTrader: (1)

I've got the dual fan set-up on my car....the passenger side fan is hooked up direct and I spliced into the relay and ran a toggle switch to the drivers side fan...I can turn it on whenever I want...and it drops by atleast 20 degree's...runs about 200...and when driving...even cooler because of the SS hood...letting alot of much needed air into the engine bay

FMCobra427

Hey im glad to see im not the only person with this problem , my 92 z is doing the same exact thing, i would like to change out the temp sensors for the fans but can find them , i have followed the wiring from the fans and still can find the sensors. any suggestions?
thanks

FMCobra427

yes i do have an autometer temp gage , and the stock gage has been disconneted.. fans kick on at almost 255 and i had to splice the drivers side fan in to the passenger side fan cuz it would not kick on .... unfortunatly i am like the 16th owner of the car and alot of the wires have been cut and spliced long before i owned the car , so have gone over almost every wire in the intire car and and have fixed alot of the wiring
thanks again


Hey im glad to see im not the only person with this problem , my 92 z is doing the same exact thing, i would like to change out the temp sensors for the fans but can find them , i have followed the wiring from the fans and still can find the sensors. any suggestions?
thanks

ultimatefighter

What and where is the IAT sensor located? More info on relocation would be cool. As far as the fan temp sensors, where are they located? 1992 Z28 has dual fans. I have spliced the two together and they run all the time. But in the process, i keep blowing fuses. So, finding the sensor to make the fans come on at a lower temp. would help.

BigBadLou

iTrader: (3)

The IAT is on the underside of the upper intake, towards the back. Very hard to get to. But it has a connector in the harness, a few inches behind the manifold.

The ECM controls both fans and it uses the signal from the CTS in the front of the manifold (below the T-stat). You cannot change that at all. But you can burn a chip with different temperature settings for the fans to kick in.

The secondary fan is controlled also by the hi-temp switch that's in the passenger side head, between the last (rearmost) two cylinders. There's only one wire going to that switch. If it's burned or cut, you'll have problems with the secondary fan. That switch can be replaced (for a lot of money) with a lower-temp switch or you could get a cheaper lower-temp switch (like 180F) and mount it elsewhere, where it would be even more accessible.

What fuses are you blowing? The main fuse by the battery or the fan relay fuses under the dash?

Lou