Hi everyone i just recently had my car overheat pulled over at gas station open radiator cap added water to cool it down. drove it for about 10 min temp when all the way up again. So i pulled over to another gas station added water again. i needed to drive at least 50 miles to get home so i decided (and it was a stupid decision) that i will go as far as i can since it was 2am and didnt wanna wake up anyone to go get me at that time. so i drove it and temp kept going up and down for about 20 miles. after that the temp did go all the way up but the engine didnt sound or feel like it was forcing it self so i thought maybe and just maybe my temp sensor was bad, and maybe 5 miles before i was home the gauge just gave out and went all the way to its coolest temp.. so i drove all 50 miles like that when i got to the exit for my house and i did a complete stop the car turned off and didnt start again. so i left it there walked home went for car the next day. i added water to see if it would start and it did for about 10 seconds with no knock on engine then it would turn off. i saw there was water leaking somewhere from around or behind water pump. so i assumed it was my water pump. also the sensor thats on one of the heads looks like it popped out of place not the whole thing but part of sensor with the connector. i did check the oil to see if maybe i got water to my oil but there was none. so a week latater i replaced water pump. and car started with no knock on engine but water started forcing it self out of radiator cap so i tried it again and same thing. i decided to check oil and the water i had just added to had just gotten in to my oil so i didnt and havent started car again. i know im gonna need to do a head gasket job and resurface heads. my question is will a head gasket job be all i have to do since engine didnt knock and was running smooth all the way?? sorry for so long story just wanted to give details on the issue.. Any advise or opinions will be greatly appreciated. Thanks!

 

No doubt on the head gasket job. You may get lucky because aluminum heads are less likely to crack rather than cast. The sensor on the side of the head is a temp sensor and when it got too hot it broke off as to why your guage stopped working. Be sure to find the source of why it overheated in the first place waterpump, cooling fans... etc or you will be doing the whole process again. Also you may get your valves and all checked out along with a pressure check. The bottom end should be ok just make sure you get that water out asap and dont let it sit up too long.

Brian

94 Z28 4l60e. Reworked heads ported and polished. Cam 3" catback flowmasters. And common bolt ons.

Any help or advice i give is my 2 cents and is based on my experience with the F-Bodies. As always seek professional help for certain problems.

 

yes brian it seems like the issue was a bad water pump which i replaced already along with thermostat,hoses,and temp sensor. i did drain the oil that mixed with watar and drained radiator. i will be taking it to a shop to get the gasket job started soon and go from there. i appreciate your reply..

 

Coolant and bearings don't get along. It is just a matter of how much damage might have been done to them.

 

That is a famous word for a vehicle that overheats. Waterpump. A waterpump rarly fails as far as mechanical wise now as far as leaking they do. Then the leak can cause bearings to go and will run your car low on coolant. also a bad water pump can cause it to loss prime(circulation). Word of advice anytime somebody tries to sell you a car that overheats and says it needs a waterpump. Run like Hell. One of the most common things ive experienced with GM cars over heating almost always started with the cooling fans not kicking in properly and causing it to overheat then comes the damaged headgasket and downhill from there. Ive also experienced a v6 camaro that over heated by having a broken faulty headbolt that came from factory. Just look the car over real good amd you should be fine.

Brian

94 Z28 4l60e. Reworked heads ported and polished. Cam 3" catback flowmasters. And common bolt ons.

Any help or advice i give is my 2 cents and is based on my experience with the F-Bodies. As always seek professional help for certain problems.

 

when the temp gauge goes down after overheating usually means you've run out of coolant and the sensor is just touching air.

are you sure you didn't blow a hose?

 

Back in the early 2000's I had a cooling fan fuse blow which allowed my LT1 to overheat during idle. I was running the engine looking at a laptop and didn't realize the temp(the car threw an AIR pump code...that was casue of the blown fuse...neither the cooling fans or air pump would work). I started smelling coolant, looked up, and the temp was pegged at 260*. I replaced the fuse which cooled it down, but I wonder if I cooled it down too quick.

The temp started moving all over the place at 60mph cruise. Where it normally would stay at 190* it would go up to 220*, back down to 190* and generally move around.

A very smart tech at Woodall Chevy pulled a hydrocarbon test on coolant(all his other tests seemed normal) which turned out high. He pulled the heads and found them warped 0.003-0.005". They were resurfaced and the cooling problem was solved. The tech showed me the head gaskets and you could see where the coolant was moving and crossing between passages at the head.

I may have spent only a total of 2 hours with him over 3 years but I learned a lot from him. By far, the best Automotive Tech I have ever met. I only know him by his first name...Joey, if I recall correctly.

It also came back sounding meaner. I'm sure it bumped up the compression ratio, but I'm not sure how much. I had a friend make a comment after I got the car back that it sounded meaner.

The CC503 I have now has made it quite a bit meaner too.

I recently invested in an 160* thermostat. Since my cam install, the car went from 190* at cruise to 210-215* at cruise. Now with the 160 thermostat, it sits at 175-180* at cruise. I'm very pleased with what it has done to the running temps. The low speed fans are enough to cool it down now. The high speeds never cycle now. I'm a happy camper with the cooling now.

Just a passing thought on the LT1 cooling system.....

One thing I've been thinking on doing is a video on how to properly fill an LT1 cooling system. Sooooo many people make the mistake of toying and fiddling with the coolant bleed valves on an LT1 it gets them in trouble. When filling the system, once you have coolant coming out of them in a strong steady stream, you close them and never open them again during the process. Never open them with the engine running.