Ok, I'm continuing to have intermittent overheating problems. I've had a pressure test done on this thing twice, both negative, yet the mechanic insists it *must* be the head gasket...mostly because they can't figure out what is wrong with it. That's a convenient conclusion for them but not for my empty pocket book.

Yes, I'm continuing to find build up of air in the coolant system. I bleed before I go anywhere but this doesn't always 'fix' the problem. If I start and it doesn't over heat within a mile or two then I can drive anywhere I want for as long as I want without it overheating...as long as I don't shut the engine off. I can bleed the air (engine running, rad cap off, burping hose until no bubbles come out) yet have it overheat anyway. It has a new thermostat in it. I suppose it could be bad but that wouldn't really explain the air getting into the system.

I can't locate a coolant leak other than the very rare instance of very mild spitting of liquid when turning the heater on. But like I said, it is extremely mild and only happens once in a great while yet the overheating issues occur at a rate of like 10:1.

The oil nor coolant fluid show any sign of intermixing (no cottage cheese type gunk).

I did find some information on the net indicating that a bad fitv could allow a vac leak into the coolant system. I had to really hunt to find that though so I'm wondering if this remote cause is even realistic.

What am I overlooking? Do I need to give in to the possibility of it being a head gasket despite neg tests? I'm getting very frustrated because this is controlling my life at this point - no other transportation and missing appointments, school, etc.

87 teg ls

 

bump for you cuz i'm stumped. i'm assuming you've checked all the obvious stupid stuff, like all those annoying little radiator hoses? there's a bunch of tiny ones in the back of the engine. you mentioned whenever you turn the heater on it bubbles...maybe the heater core isn't getting bled properly for whatever reason? what about a hairline crack somewhere in the radiator? my 95 ls, i changed a radiator hose and just topped off the coolant, didn't even bother to bleed it and i've had no overheating issues. i've even taken it on a few 4 hour drives (each direction)

good luck!

 

Thanks. I have talked to many a good-old-boy mechanic around here, all of which insist it is a different problem and offer up reasons why everyone else is wrong.

I've had...
hairline crack in the block-shivers
bad head-more shivers
bad thermostat-you really can buy a bad new one
radiator leak-can't seem to find one
bad radiator cap-has a new one
water pump
many others I can't even remember at this point

I got pissed, fed up after yet one more over heat and pulled it off into a parking lot to cool. When it cooled I pulled the thermostat out of it and ran it fine for a week. I purposely drove around aimlessly in city traffic, hwy, sharp inclines and such putting a few hundred mi on it with my longest trip being a 1.5 hr drive on the turnpike running 75mph with a 15 min of idling at halfway before turnaround, lots of idling in general...it was fine.

Assuming I had gotten a bad thermostat, I bought a new one and replaced it today, bled the system and started it up. Initially, all was good. I drove around, let it idle while i filled up the gas tank, drove some more, then to pick up some more anti-freeze at Walmart as I'd had to use just water to top it off. I was in the store 15 mins, get back and start it up again and I'll be d@ng if it didn't overheat again, in less than a mile!!! Same story as before.

So, thinking I'd been sold the wrong thermostat (was sold the offset design, no longer have the original one I pulled to compare, and while I *thought* I checked before I put in the first new one then tossed the old one...maybe I didn't??) I called the dealer and asked about one, had to order it-of course, so needing to get this taken care of now, I asked them to check on the design for me. The person I talked to said they weren't sure, the picture they had to look at was hard to tell but walked out to check with the mechanics and was told that as far as they knew, they were pretty sure it was the offset design. Pretty sure...that's about as reassuring as the mechanic who was *pretty sure* it was the head.

I'm tired of buying and replacing thermostats. It's not an engine overhaul but it isn't topping off the gas at the pump either. It runs fine, albeit cold, without a thermostat so I'm going to just pull it and be done with it. Yes, my heater will be worthless but at least I can get from point A to point B.

Other than that, kerosene and a match are looking really good right now