Car is running hot after replacing everything
#1
Car is running hot after replacing everything
Noticed my car is running hot. I have a 160 thermostat and it used to cruise at 160 on the highway and when it reached 230 in stop and go traffic, the fan would kick on and drop it down to 210 before it rising back again and or getting on the highway to drop it back down to 160. But now when im on the highway it wont go under 190 and will slowly creep up to 210 and just stay there. Now in stop and go traffic it goes up to 220 and slowly rises to 230 before the fan kicks on and keeps it at 230. I replaced the thermostat, water pump, radiator, radiator cap, and even flushed some of the cooling system cleaner through it with fresh coolant and still nothing. This is driving me nuts and im getting ready to stay screw it and LS swap the damn thing. Possibly throw the 350 in something else.
#2
Supreme Member
Re: Car is running hot after replacing everything
Seems like it was running normally before. I'd put a factory thermostat back in.
#3
Re: Car is running hot after replacing everything
#4
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: Car is running hot after replacing everything
Does your car have the factory air dam? Is this a single or dual fan setup? Was the outside temperature the same before chsnges were made or was it in coolef weather? Why are you waiting until 230F to turn on your fans. You can get a low tempersture fan switch and altered tuning to turn the fans on much earlier.
Last edited by Fast355; 07-13-2022 at 12:12 AM.
The following 2 users liked this post by Fast355:
T.L. (07-13-2022), WeBurnNRubber (08-12-2022)
#5
Re: Car is running hot after replacing everything
Does your car have the factory air dam? Is this a single or dual fan setup? Was the outside temperature the same before chsnges were made or was it in coolef weather? Why are you waiting until 230F to turn on your fans. You can get a low tempersture fan switch and altered tuning to turn the fans on much earlier.
#6
Re: Car is running hot after replacing everything
Alright so I made another discovery. So I know my radiator is working because I grounded one of my cooling fans and had it run continuously and noticed it didn’t get above 200. Now that’s at stop and go traffic and cruising on the highway. But when I turned it off and ran it on the highway, it started to creep up again. So now I’m thinking it’s an airflow issue. I have the air dam and all three pieces intact with no blockages. I also took out the ac condenser in front of the radiator so now it’s a straight shot through towards it. I had no thermostat in it and then put the new 180 back in and it still behaves the same. So now I’m even more stumped.
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#10
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Car: 1983 Z28
Engine: L69
Transmission: T5
Axle/Gears: 3.73
Re: Car is running hot after replacing everything
Noticed my car is running hot. I have a 160 thermostat and it used to cruise at 160 on the highway and when it reached 230 in stop and go traffic, the fan would kick on and drop it down to 210 before it rising back again and or getting on the highway to drop it back down to 160. But now when im on the highway it wont go under 190 and will slowly creep up to 210 and just stay there. Now in stop and go traffic it goes up to 220 and slowly rises to 230 before the fan kicks on and keeps it at 230. I replaced the thermostat, water pump, radiator, radiator cap, and even flushed some of the cooling system cleaner through it with fresh coolant and still nothing. This is driving me nuts and im getting ready to stay screw it and LS swap the damn thing. Possibly throw the 350 in something else.
Replaced my radiator, a new Delco solved my issue. I did that last even though I had pulled mine radiator and ran the garden hose through it and it seemed to flow fine. It ran considerably cooler after that and the OE was only about 10-12 years old at the time.
#11
Re: Car is running hot after replacing everything
So i have a mechanical gauge since my dash one went out. i also bought a temp gun and it reads around the same as the mechanical gauge. Now im currently running my cooling fan switch always grounded. it seems to cruise around 190 to 200 now at any speed. Highway, stop and go, etc. Could a bad heater core possibly cause this? its the one thing i havent replaced yet
#12
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Car: 90 Formula / T-tops
Engine: 305 TPI
Transmission: MD8
Re: Car is running hot after replacing everything
4 questions:
what happens when one fan on, one fan off sitting still
what happens when one fan on, one fan off going down highway
what happens when both fans on? sitting still
what happens when both fans on? going down highway?
more questions:
Are you certain your water pump is working? Can you see it exchange coolant?
Does your radiator have the foam insulation on the sides which forces air thru it, rather than letting air slip around it?
what happens when one fan on, one fan off sitting still
what happens when one fan on, one fan off going down highway
what happens when both fans on? sitting still
what happens when both fans on? going down highway?
more questions:
Are you certain your water pump is working? Can you see it exchange coolant?
Does your radiator have the foam insulation on the sides which forces air thru it, rather than letting air slip around it?
#13
Senior Member
Re: Car is running hot after replacing everything
GM wanted these motors to run hotter for exhaust pollution reasons. I am running a 180 or 185 tstat (whichever). If your car runs better/cooler stay with the 160*. My '72 Buick GS factories for 195* tstat which meant the engine ran well over 200* I replaced with a 180* & and all was well.
The Buick engines have a lot of nickle in the blocks & can withstand heat far better than the chevy blocks.
The Buick engines have a lot of nickle in the blocks & can withstand heat far better than the chevy blocks.
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