highway speed overheating
#17
Re: highway speed overheating
You'll be perfectly fine running a 160* tstat without programming. I did it for a long time. Highway temps will be lower, otherwise everything else will pretty much be the same since the fans come on at the same temp.
#18
Re: highway speed overheating
The problem with lower coolant temps is not due to the PCM and the coolant temp reduction. The PCM knows the exact air flow into the engine because of the MAF sensor, and proportions the fuel correctly for that air flow.
The problem is that as combustion chamber temps drop, the burn is less complete, so you dump some unburned fuel out the exhaust. But I doubt you will even notice it. You are also throwing away more of the combustion BTU's, since they are being lost to the coolant, so the engine's thermal efficiency drops. But in the case of the LT1, this appears to be offset by the gain in air density due to the reduced heat transfer in the intake manifold.
With the lower coolant temps, you may also be able to add a bit of ignition advance, which may help power and fuel efficiency.
But he has to solve the overheating problem first.
The problem is that as combustion chamber temps drop, the burn is less complete, so you dump some unburned fuel out the exhaust. But I doubt you will even notice it. You are also throwing away more of the combustion BTU's, since they are being lost to the coolant, so the engine's thermal efficiency drops. But in the case of the LT1, this appears to be offset by the gain in air density due to the reduced heat transfer in the intake manifold.
With the lower coolant temps, you may also be able to add a bit of ignition advance, which may help power and fuel efficiency.
But he has to solve the overheating problem first.
#19
Re: highway speed overheating
Would a temperature that is too low cause it to stay in open loop?
Just curious that you don't have a problem any other time then going at highway speeds and you say you have some sort of grill that is not OEM.
Why not try it with the grill out and see what happens?
You did pull the top support to see if there was debris in between the condenser and the radiator right? FWIW, mine had one of those plastic shopping bags in there.
Just curious that you don't have a problem any other time then going at highway speeds and you say you have some sort of grill that is not OEM.
Why not try it with the grill out and see what happens?
You did pull the top support to see if there was debris in between the condenser and the radiator right? FWIW, mine had one of those plastic shopping bags in there.
Last edited by Guest47904; 09-29-2011 at 05:41 AM.
#20
Re: highway speed overheating
#23
Re: highway speed overheating
You Said it is running at 260 on then highway? that is insane you should not be driving it even at 210 that its gonna cause some melting of gaskets. happened to my brother he put a lt1 in his jeep and didnt realize the common temp. fluid has to be getting lost somewhere. or not enough in the system.. check to see if your reserve tank is leaking underneath the battery. is the fluid bubbling out with cap off and car hot? may be a bad waterpump not spinning..
#24
Re: highway speed overheating
You Said it is running at 260 on then highway? that is insane you should not be driving it even at 210 that its gonna cause some melting of gaskets. happened to my brother he put a lt1 in his jeep and didnt realize the common temp. fluid has to be getting lost somewhere. or not enough in the system.. check to see if your reserve tank is leaking underneath the battery. is the fluid bubbling out with cap off and car hot? may be a bad waterpump not spinning..
Look for the basics....is the coolant level normal, is there flown the cooling system, is the air flow path blocked, etc. Since the problem started after a mod was performed that's the first logical place to look...
#25
Ding ding ding ding
The last statement is the DUH moment.
#26
Re: highway speed overheating
Coolant is full, no leaks. A faulty thermostat looks like it. I'm going to bleed the system one more time. I definitely am changing the tstat and rad cap since there 14yrs old and cheap to replace
Last edited by LT1Mike; 09-30-2011 at 12:24 PM.
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