To Hot / Overheating?
Thread Starter
Racer
Joined: Feb 2001
Posts: 276
Likes: 0
From: Springboro OH
To Hot / Overheating?
While driving home last Fri. in traffic (outside temp 90) my '88 got hotter than I think it has in the past (up to 245 then cooled down to about 218 then back up again). So when I got home I popped the hood to see if the fan was on and it did not go on until the temp reached 240. Other than that I could not find anything out of the ordinary so I thought I would give it a shot again this morning with the outside temp 55. The same thing happened it would shoot up to about 250 - 255 then come down to about 218 then go back up again. This happened when I was cruising at 40 with no one in front of me, or when I was stopped in traffic. I don’t remember the temps ever getting that high, it seems that the fan is kicking on at a higher temp, has anyone ever had this problem? Im thinking it might be one of the sending units, which one is the gauge and which one is for the fans? Also how high is to high, in all the years I have owned a Chevy I have never had one run this hot, if I see 220 in my other cars I'll pull over to the side of the road to see whats wrong. Experience tells me that 240-250 blows head gaskets and other nasty things, isnt that the case here also?
Any thoughts would be helpful, thank you,
Joe
Any thoughts would be helpful, thank you,
Joe
Pro
Joined: Sep 2001
Posts: 743
Likes: 4
From: Guyton GA
Re: To Hot / Overheating? (joalyons)
The fan should be turning on and off at the same temperatures. If it does vary then your problem maybe your coolant sensor. You should also check for garbage build-up between your radiator and condensor.
Le Mans Master
Joined: Aug 2000
Posts: 5,192
Likes: 1
From: Airport Cruise-in 1 Veteran Airport Cruise-in 2 Veteran
Cruise-In II Veteran
Re: To Hot / Overheating? (merrick)
You should also check for garbage build-up between your radiator and condensor.
Mine ran a lot cooler after cleaning it out. On a 90 degree day my temps would hit 235 and 248+ on a 100 degree day. That is with my fans set to go on @ 184 and using a 160 stat. After I cleaned out just the debris the temps go down when the fan turns on and oil temp has yet to pass 210 since.
[Modified by War Machine, 11:22 AM 3/25/2002]
Thread Starter
Racer
Joined: Feb 2001
Posts: 276
Likes: 0
From: Springboro OH
Re: To Hot / Overheating? (joalyons)
Update: Ok I think I have an internal coolant problem, hears why: When I started the car yesterday morning I noticed a lot of condensation in the exhaust, so much that I pulled over and checked the oil for any signs of water. There was none so I just thought maybe its natural (now in retrospect, we don’t get that much condensation in the exhaust in AZ). Driving home last night it got really hot 260+ so I pulled right over and let it cool down. I did this several times to get home. When at home I was checking to see if there was good coolant flow in the radiator (thinking maybe I had a stuck thermostat) and noticed the condensation again. There is still no noticeable sign of coolant in the oil but the overheating and moisture in the exhaust lead me to believe a blown head gasket or worse. Any other thoughts? :confused: :eek:
Drifting
Joined: Jun 2001
Posts: 1,490
Likes: 17
From: Darlington, MD
Re: To Hot / Overheating? (joalyons)
Mine runs about 185 while moving and will go up to about 190- 200 while stopped at a light, depending on how long the light is. I think the fan is supposed to kick on @ 230. It sounds like you have a problem. Good Luck, Guy
Team Owner
Joined: Sep 2001
Posts: 62,160
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: To Hot / Overheating? (joalyons)
so you dont think your thermostat is sticking? have you checked for any coolant leaks from the outside? is your radiator full and your overflow tank where it should be?
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Thread Starter
Racer
Joined: Feb 2001
Posts: 276
Likes: 0
From: Springboro OH
Re: To Hot / Overheating? (joalyons)
There do not appear to be any leaks externally, no puddle under the car, etc. I think the coolant level went down slightly, maybe two or three inches from the top of the radiator in 50 miles.
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Re: To Hot / Overheating? (joalyons)
Additional thoughts:
Carpet in the passenger footwell dry? Does the heater put out hot air?(turning it on full blast will help aid cooling in a emergency situation)
The coolant is how old? Last date/mileage of cooling system servicing? What fans come on? The main and or the aux fan in front of AC condenser? All leads and connections still connected? ie: temp sender lead not laying on the exhaust manifold<----from personal experience :crazy:
Coolant in oil will be whipped into tapioca pudding by the reciprocating assembly.
even further effort: pull spark plugs, turn engine over, see if cylinder pressure "spews" out forcefully any moisture <-----more personal experience :lol:
Stock computer chip still in the car? radiator cap holding pressure?
[Modified by 89 Paul in cal, 1:01 PM 3/26/2002]
Carpet in the passenger footwell dry? Does the heater put out hot air?(turning it on full blast will help aid cooling in a emergency situation)
The coolant is how old? Last date/mileage of cooling system servicing? What fans come on? The main and or the aux fan in front of AC condenser? All leads and connections still connected? ie: temp sender lead not laying on the exhaust manifold<----from personal experience :crazy:
Coolant in oil will be whipped into tapioca pudding by the reciprocating assembly.
even further effort: pull spark plugs, turn engine over, see if cylinder pressure "spews" out forcefully any moisture <-----more personal experience :lol:
Stock computer chip still in the car? radiator cap holding pressure?
[Modified by 89 Paul in cal, 1:01 PM 3/26/2002]
Advanced
Joined: Mar 2002
Posts: 51
Likes: 0
From: Moorpark California
Re: To Hot / Overheating? (joalyons)
I had an overheating problem too with my 88. It would heat up to 240 or so then go back down when I get up to speed. One day it shot up to 260 I pulled over had a few beers while waiting for it to cool down. When I got going again temp was about 230 and dropping it finally went down to 180 and was running fine till I got home. I then took the car in to get the t-stat replaced, and the mechanic told me there was carbon (or something like that) and said I might have a blown head gasket. I took it to another mechanic (It was still under warranty) It turned out to be the water pump going bad. Sometimes it woud work someetimes it wouldn't work.
Pro
Joined: Sep 2001
Posts: 743
Likes: 4
From: Guyton GA
Re: To Hot / Overheating? (joalyons)
Update: Ok I think I have an internal coolant problem, hears why: When I started the car yesterday morning I noticed a lot of condensation in the exhaust, so much that I pulled over and checked the oil for any signs of water. There was none so I just thought maybe its natural (now in retrospect, we don’t get that much condensation in the exhaust in AZ). Driving home last night it got really hot 260+ so I pulled right over and let it cool down. I did this several times to get home. When at home I was checking to see if there was good coolant flow in the radiator (thinking maybe I had a stuck thermostat) and noticed the condensation again. There is still no noticeable sign of coolant in the oil but the overheating and moisture in the exhaust lead me to believe a blown head gasket or worse. Any other thoughts? :confused: :eek:
