New engine over heating!
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Car: 1988 IROC-Z28
Engine: L98(383tpi) modified
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New engine over heating!
I recently got my Iroc up and running again after replacing a cracked block that I purchased a few years ago unknown to me at the time. Anyway I pretty much have the same configeration as before, and the engine is alot cooler now. But after running it for say a 1/2 hour to an hour. Shutting it off, and then restarting it multiple times to dial in the idle etc. I find the engine over heats. I have a Haygen electric cooling fan that works great and turns on at about 160-170º. I also have a 3 core radiator, 160º thermostat, and I'm using a 50/50 mix. I was thinking that I may have a air pocket. I've let the engine run with the radiator cap off til the coolant is about to spill out, but I don't know if thats good enough. Also my engine temp. doesn't get over 180º.
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Re: New engine over heating!
does the fan turn on?
the car may run warmer sitting still in a confined space, like a garage, with little air flow.
the car may run warmer sitting still in a confined space, like a garage, with little air flow.
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Re: New engine over heating!
Yes the fan does come on, and your right 180º is not over heating. BUt when your coolant resevoir boils and over flows out theres a problem some where. And yes I top the coolant resevoir of at the cold water line. If I shut the engine off after running for say 15-20 minutes, the resevoir will began to boil. So I then turn the fan on at the accessory mode, and it cools down. But last night after test driving up and down my driveway (which I can park about 8-9average size cars on. I noticed it was over heating again with the coolant boiling out of the resevoir. The temp got as as high as 180º maybe 185º. So thats why I was wondering if theres a air pocket, or am I just pushing the engine to much in a confined area such as the garage and up and the driveway. I don't want to take it on the street til all the bugs are worked out.
#5
Re: New engine over heating!
As GTA said 180 isn't overheating. Stock thermos are 195 and the fan won't kick on till about 225 (too hot for me). If coolant is coming out of the resevoir, then you must have too much coolant in the system. I have my fan running all the time in the summer cause even driving down the road, it stays cooler with the fan on.
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Re: New engine over heating!
I thought so too, but I toped it off at the cold line. Also I didn't top the radiator of from the last time it over heated. So I went up and down the block a couple of times and it started to boil over at the resivoir after I pulled back into the garage to readjust the idle which I had to shut the engine off to do. So I turned to accessary only to get the fan back on, and the boiling stopped.
#7
Re: New engine over heating!
Hmnmm, your radiator might be the problem. You are not overheating, you are not over filling it, and it over flows unless you have the fan on after shut off. Is your coolant res stock? My hunch is it's your radiator. Its not hard to r&r you radiator, I'd try a stock one if you still have it, and see if it happens again.. Engines get warmer when they are shut off, but its normal
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Re: New engine over heating!
Its a 3 core radiator though, were as the stock ones are 2 core. I also sold my stock one a year ago.
What if I try water wetter?
What if I try water wetter?
#9
Re: New engine over heating!
How much do you loose when it boils over? On my 92 rs the reservoir is larger than on my 86 iroc. How about filling the radiator w/the reservoir empty. If your system is holding more coolant than it used to, than I think you maybe need less
Last edited by Stevolwevol; 07-05-2009 at 08:34 PM.
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Car: 1990
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Re: New engine over heating!
new engines always run hot and can boil over. they say not to run new headers on a new engine because they get so hot they crack the coating.
i had a new 85 or 86 cross fire and it overheated a few times during breakin and then no problems for the 3 years i had it.
its part of the breakin.
and is your water pump flowing in the correct direction?
i had a new 85 or 86 cross fire and it overheated a few times during breakin and then no problems for the 3 years i had it.
its part of the breakin.
and is your water pump flowing in the correct direction?
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Re: New engine over heating!
If you're positive that you're not overheating, temp wise, its possible you have a bad head gasket or something, leaking compression into your coolant passages.
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Re: New engine over heating!
How about filling the radiator w/the reservoir empty. If your system is holding more coolant than it used to, than I think you maybe need less
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Car: 1990
Engine: 305
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Re: New engine over heating!
about 500 miles. i liked to take mine on a 300-400 mile trip - not all at one time, but lots of driving. i want eveything to seat properly. at 600 miles i change out the oil and filter. we used to use break in oil but not anymore.
lots of sitting and running does make it run very hot.
take it for a long ride, not over 65 but a nice long few hours - but others will disagree. but it cant hurt. carry some extra water with you.
lots of sitting and running does make it run very hot.
take it for a long ride, not over 65 but a nice long few hours - but others will disagree. but it cant hurt. carry some extra water with you.
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Car: 1988 IROC-Z28
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Re: New engine over heating!
Thanks for the info. It is been garage only running and a couple of trips up and down the driveway. I just started to drive it up and down the block this evening. I'm afraid to go to far to soon in case something goes wrong which always seems to be the case for me. (MURFYS LAW)
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Re: New engine over heating!
I wouldn't be afraid to run w/less coolant. How much do you loose when it boils over? After it boils over, will it do it again if you don't add coolant?
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Car: 1987 iroc z
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Re: New engine over heating!
everytime you shut your car off after it cools enough to let the cap do its job it will release presure into the overflow tank making it look as if its boiling.
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Re: New engine over heating!
My battery died on me from to much cranking I guess, so I have to wait til Friday (payday) before I can try again. I'll keep you posted!
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Re: New engine over heating!
I doubt it is overheating. Probably air pockets burping after the engine is shut down, especially if it is new. run it awhile with the radiator cap off to purge air pockets and keep filling with coolant
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Re: New engine over heating!
IF YOU ARE LEAKING FROM A HEAD GASKET AND PUMPYING ANTIFREEZE into your engine - just look at the dip stick. if it looks like a frothy milkshake - you got coolant in the oil.
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Re: New engine over heating!
IF YOU ARE LEAKING FROM A HEAD GASKET AND PUMPYING ANTIFREEZE into your engine - just look at the dip stick. if it looks like a frothy milkshake - you got coolant in the oil.
I doubt it is overheating. Probably air pockets burping after the engine is shut down, especially if it is new. run it awhile with the radiator cap off to purge air pockets and keep filling with coolant
How much do you loose when it boils over? On my 92 rs the reservoir is larger than on my 86 iroc. How about filling the radiator w/the reservoir empty. If your system is holding more coolant than it used to, than I think you maybe need less
#29
Re: New engine over heating!
Wow your having the same problem i am currently. Car runs fine at idle warms up to around 160. Someone must of wired the fan to always be on (so it seems). Driving conditons it warms up to 210-220 which some say is normal but way scary for me. Park and shut off i see it back up in the tank and burpin. i have no oil in the coolant nor coolant in the oil. filled the rad while the car running to get air pocket out, changed hoses and tstat to the 160. Ive bought a tranny cooler to mount after i do the tranny flush. I def dont want my tranny fluid running thru this hot as rad. I know we have been seeing hotter days here in Tx and this is my 1st summer with her but damm almost makes me want to leave her in the garage.
Car burns some oil and needs a head job but i still have a gut feeling im leakin by on the head gasket.
Car burns some oil and needs a head job but i still have a gut feeling im leakin by on the head gasket.
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Re: New engine over heating!
Just an update on mine. It seems to have stop, and I let the cooling fan run for about 15 minutes.
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Re: New engine over heating!
Yea it holds at 180º, I need to re connect my fan over ride switch though, because when I shut the ignition off the cooling fan also shuts off. A minor inconvenence, but the temp does get upto about 200-210.
HtOwNs 87Rs
Get a coolant pressure tester you can even rent them at a parts store.
Thats how I found out I had a cracked block a year and a half ago.
HtOwNs 87Rs
Car burns some oil and needs a head job but i still have a gut feeling im leakin by on the head gasket.
Thats how I found out I had a cracked block a year and a half ago.
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Re: New engine over heating!
I did what was recommended in a earlier post suggestion and that was let the coolant boil out don't re-fill it and see how it goes. Well it worked along with letting the cooling fan run for about 15 minutes.
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Re: New engine over heating!
Have you tried shutting off the engine, and not running the fan? The coolant in the block will heat up regardless of the fan running. The coolant in the radiator will start to cool w/o the fan.
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Re: New engine over heating!
So your still running around the same temp minus the boiling stuff? Hmmm
I think the boiling stuff was air pockets that needed to be worked out.
#41
Re: New engine over heating!
well thats good u got ur fixed.....
me on the other hand have a failed head gasket....use the block tester lastnite and it changed the fluid from blue to green within a few pumps.
So list of volunteers lol
me on the other hand have a failed head gasket....use the block tester lastnite and it changed the fluid from blue to green within a few pumps.
So list of volunteers lol
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Re: New engine over heating!
me on the other hand have a failed head gasket....use the block tester lastnite and it changed the fluid from blue to green within a few pumps.
that sucks...
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