Overheating
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Teching In
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Overheating Hey all, this is my first post on here. Excited to be a new ls1 owner...
Here's the skinny...
Swapped in an ls1 into a 91 Z28. And it is overheating. Here is what I have done/looked at.
1. Swapped tstat for good measure
2. Elevated front end, ran the car til it warmed up with heater on full blast to push air pockets out of engine/heater core
3. coolant stays full and there are no leaks anywhere.
4. The water pump isn't leaking anywhere, and has no play on the pulley.
5. Dual electric fans kick on
I'm really just at a loss as to what else to try so I can finally get on the road and drive the car! Any help would be appreciated.
Here's the skinny...
Swapped in an ls1 into a 91 Z28. And it is overheating. Here is what I have done/looked at.
1. Swapped tstat for good measure
2. Elevated front end, ran the car til it warmed up with heater on full blast to push air pockets out of engine/heater core
3. coolant stays full and there are no leaks anywhere.
4. The water pump isn't leaking anywhere, and has no play on the pulley.
5. Dual electric fans kick on
I'm really just at a loss as to what else to try so I can finally get on the road and drive the car! Any help would be appreciated.
Is it overheating while driving or while idling?
When moving you really shouldn't need the fans.
What radiator do you have? New?
Jack the front of the car back up again and unbolt one of the steam vent plugs until water comes out. That will guarantee all the air is out of the motor.
When moving you really shouldn't need the fans.
What radiator do you have? New?
Jack the front of the car back up again and unbolt one of the steam vent plugs until water comes out. That will guarantee all the air is out of the motor.
Thread Starter
Teching In
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It overheats during idling, and continues when driving. The radiator is a stock 3rd gen radiator. It worked fine when the old engine came out. And has the capacity to keep this one cool. How high up would you recommend me jacking the front of the car up? Currently the tires are up about an inch off the ground, I would think that's enough but I could be wrong.
And by overheating, I mean continuing to climb until hitting the red and I shut the car down.
And by overheating, I mean continuing to climb until hitting the red and I shut the car down.
Get the top of the radiator above everything else.
Does sound like air in the system. You may need to burp it a couple of times. Pulling the steam vent plug will get all the air. They are o ringed so no worries about hurting anything.
What fans? Are they well shrouded?
Does sound like air in the system. You may need to burp it a couple of times. Pulling the steam vent plug will get all the air. They are o ringed so no worries about hurting anything.
What fans? Are they well shrouded?
Last edited by Pop N Wood; Jun 28, 2016 at 08:32 AM.
Thread Starter
Teching In
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They are the stock dual electric fans from the third gen.
I will try and bleed it that way again. I've tried a couple times. I will jack the front end up quite a bit higher to see if it helps at all.
Thanks for the help so far.
I will try and bleed it that way again. I've tried a couple times. I will jack the front end up quite a bit higher to see if it helps at all.
Thanks for the help so far.
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That is much hotter than we used to want in the carburetor days, I used to freak out at 195 - 200. Hahaha.
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Teching In
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Listen to that man^^^. i just did what popNwoods recomends. I did not have water circulating on my lq9 79 trans am. Did as above and my car now runs at a constant 200-210 with stock 86 celcius thermostat.. with stock 79 trans am radiator. most likely you dont have water behind the thermostat.
Thread Starter
Teching In
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The accessories are all stock including the water pump (or at least it's the original from the donor). I am in the middle of swapping out the water pump since it's only $150. I am then going to follow the process mentioned above about the steam vent plugs when I refill it with coolant.
Thread Starter
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Well I don't think it was the water pump. Swapped it out, refilled the coolant and tried bleeding it doing the vent plug process and still can't get it to quit overheating. It doesn't even look like the coolant is circulating. Maybe I'm crazy. I don't know at this point.
Teching In
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are you using a stock thermostat they are 86C or 186F but checked recently and it opens up at 195F.. when you say that its overheating what is the reading it? takes more than a few minutes for that thermostat to open up. prior to that water will not circulate.
Thread Starter
Teching In
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Yep. Using a OE thermostat. I'm letting the gauge read 240ish before shutting it down. Usually runs for about 10 minutes before it hits that temp, so it is a slow, steady build in temperature.
Does the PCM see the engine overheating as well? Just wondering if the sender is even compatible with the gauge. Hook up a scan tool and verify the temps. I use the elm obd readers with my torque pro app. on my phone.
