Zeph's Final Overheat Post

Changed the water pump out. Got everything working. After a day the overheating came back. Car seemed to misfire on startup as well. Put dye in the system and saw that coolant was leaking from a vacuum cap on the end of the plenum where it meets the throttle body. Tightened the cap. Car still overheated. Couldn't figure it out. Finally, put a bottle (not the powder or tabs) of Bar's Radiator stop leak in the surge tank. Drained the coolant just enough to suck the stop leak out of the surge tank, then topped the fluid off. Started the car and let it run 10 minutes. No overheating. Took it out and drove it 25 miles. No overheating. I've driven about 100 miles with the car today after I put the stop leak in, and it has not overheated once. Also got back a lot of power. I used to think everyone was full of crap when they insisted on using those tabs. I retract that belief. I think it is very neccessary! Thanks guys.

heh. I should have know that I would be back with the overheating problem. Anyways, I think I have a small head leak when the engine is operating in the higher RPM range. The other day, the thing started to overheat when I had the engine at 2.5. Took my foot off the gas and RPMs slowly dropped (I was going at around 40 MPH). Not much temp change as RPMs dropped. But, I tried it again later. Instead of letting RPms go down slowly, I shifted the car into neutral. BAM...engine cools down immediatly.

I also began flushing the coolant system yesterday. I hooked a garden hose up to the car into what was coming out of the engine was clear water. I was even able to force the air out of the heater core. After that, put a super radiator cleaner in. (I have to drive the car for three to six hours now). About five minutes after I put the cleaner in, I began to see the mix of cleaner and water in the surge tank start to turn orange. I guess there is a huge ammount of sludge in the system. I also thing the radiator is clogged since I'm getting pretty nastly temp. difference along the radiator. So far after I put the cleaner in, I have run the car for an hour. No bubbles in coming out of the surge tank. No overeheating. I think I finally got the air out...yay! It only took me 12 weeks to figure out.....uh....I'm an idiot..I should have tried this much sooner.

I have a definite answer now. Head gasket is leaking. The problem became really noticable while I was doing a super flush. Have to drive 3 to 6 hours to get all the scale out. Stopped the car and heard bubbling (kind of like a percolator) coming from the rear head. Also now noticed white powder and a yellowish oil on the oil cap. Now I'm losing coolant fast as the car just sits there. At least I know what it is now. As soon as it cools I got to flush it once more and then do the sealer.

Later

Are you thinking that a sealer additive is going to fix a blown head gasket?

Are you thinking that a sealer additive is going to fix a blown head gasket?

No...I'm not using a sealer additive. I'm using a plain and simple sealer that requires complete removal of all antifreeze. Then you flush the system and drain again. Then put the sealer in the cooling system with water and run the car. Then in with the new coolant. I'm using bars leak headgasket sealer. It's specifically designed to cracks in the block, heads, gaskets or any other severe leaks.

But, I will leave an update later one I find out if it actually works.

Argggggggggg!

Spent the last three days flushing and sealing my block and heads and coolant system. Got everything together today. Ran it at a high idle (3000RPM x 45min) to see if it was going to overheat. It didn't. So, decided to take it for a test drive. No problems for the first 17 miles. The the thing goes nuts and overheats. It's not as bad as it was before. Only goes to about 3/4. Got home, opened the hood and checked things out. The lower radiator hose had moved into contact with the alternator pully. The last hose I had on it was completly cut through, but this new one was only cut a little bit. Heres the odd thing. Because it happened before, I made sure that there was at least a quarter of an inch between the pully and the hose. Why did this hose move?

As for the overheating, I'm hoping that it's just because there is air that is working it's way out of the system. When I came home after the drive, I did notice that the coolant level had dropped. Like I said, probably just air bleeding itself out.

I'm going to get out there again tommorrow and take a closer look at it.

I'm suprised no one suggested this. After looking online, I think it's possible that I might have a loose or broken motor mount. This explains why the rad hose keeps getting cut only when the car is in motion. Once the engine is torqued and begins to move around so does the hose. Gonna go check my mounts now.

I'm suprised no one suggested this. After looking online, I think it's possible that I might have a loose or broken motor mount. This explains why the rad hose keeps getting cut only when the car is in motion. Once the engine is torqued and begins to move around so does the hose. Gonna go check my mounts now.

Starting a new thread about this...