Just wanted to share about the cooling problems on my ’90 L98 automatic. I have historically been having over heating problems. Has never gotten to boiling over but would get dangerously close to the red hazard area in stop and go traffic. The '90 does not give a digital read out of the temp (without going into the computers diagnosis mode) has only an analog gauge that reads from 100 to 260. Looks as if the red hazard area would be about 250-260. I had grounded out the cooling fans so that they ran all the time to try to keep it cool.

Last year I pulled the shroud and shot water through the radiator from the back to clean out the fins. Unreal what came out of the areas right in front of the cooling fans. Looks like it may have been blocked solid in those areas. That would be good preventative maintenance for any C4. But this year I was getting a small water leak. Could not tell where it was coming from but the lower radiator hose was wet on top up by the water pump. So figured the pump may be going.

What to do? Decided to go all the way. I pulled the radiator and cleaned out all the cooling fins. Thought about taking it to a radiator shop for cleaning but it did not appear that bad, inside looked good. Then I pulled the stock pump and replaced it with a Stewart Stage I pump. This pump claims to flow about 40% more then stock. Put it all back together, filled it up with tap water (no anti-freeze), added Prestone rust inhibitors and a bottle of Water Wetter, and installed a 180-degree thermostat.

Results: The highest the gauge has gotten is half way up the gauge. That was on 95-degree day in stop and go city traffic. Normally is running between one third to half gauge. I am happy :D :D What did it? Don’t know if it was any single item or just a combo of all of the improvements. But if you are running warm and have never had the radiator out, I would recommend pulling and cleaning the radiator. That will probably be a huge step to solving your problems.

tom...


[Modified by Tom73, 12:41 AM 5/28/2002]

 

I plan on doing mine this summer :cheers: Good how-to in tech tips https://www.corvetteforum.com/techti...D=53&TopicID=2

 

Tom,

Glad you got your problem solved..... Mine was doing the same thing, and when I pulled the radiator this morning I found that about 1/3 of the fins on the back side had been bent...... Plus a bunch of garbage on the front, and some leaves and other things in the dead space........

I am debating on buying a tool to straighten the fins or take it to a shop to get them straightend out...... Need to do a cost analysis on this one......

Hope to have it back together by the weekend then I will find out how well the process worked.......

Hope it works as good as yours did.....

 

Thanks bro. I'm just in the middle of a major renovation to cool my 90. (A Black vette in AZ 110* degree weather.) I'll mkae sure I check out the radiator. Also that water wetter stuff probably had alot of help in your results. Lubricants/Microlubricants have also been said to get rid of all the rest of those carbon/calcium deposits all throughout the shafts which can account for about 50-60 percent of alot of people's heating probs cuz the heat gets trapped in there.