Hey everyone,

Just wondering if there is a time period or number of miles after a head gasket repair after which you can say it was done right and the HGs will hold?

My 99 STS overheated the day I picked it up (130k miles on it), the dealer took it back that day and I got it about a week and a half later, he said the final diagnosis had been the HGs and that he'd sent it to an engine specialist to replace the HGs and machine the heads, etc. Sounded like they did it right, with inserts and all that. Now, I think he got the 3rd party warranty company to pay for it, but that's a whole other story :)

So, I'm just kinda nervous right now...the temp is always at 12:00 and never budges (even during "spirited" driving :) ) but I'm just wondering if there is a point when I can start to breathe easy? Is there any sort of stop-leak that he could've just put in to make it seem like the HGs were replaced, that could soon give way?

Thanks everyone,
Jad

Chill out, drive the car, keep it clean and oiled, and don't sweat the small stuff. Your car has a long life ahead of it.

A '99 with a rebuild and 'serts is good for a long, long time.

Yeah, what submariner said.

dude it's not like surgery on a human, your car won't 'heal' itself it's either fixed or not, there is no middle ground, and the repair may not last, if you're that worried sell the car go buy something else and don't sweat it...

dude it's not like surgery on a human, your car won't 'heal' itself it's either fixed or not, there is no middle ground, and the repair may not last, if you're that worried sell the car go buy something else and don't sweat it...

Never said I thought it 'healed' itself, I just wondered if there was some sort of stop leak product that could mask a bad head gasket for a while.

It's just my nature to overthink things and worry but I'll take everyone's advice so far and just enjoy the car.

Conventional wisdom here is that there is no 'stop leak' product that would delay N* headgasket issues any signficant period of time. Never seen a post that anyone said they had any success trying that. When N* HGs go they tend to pop the headbolts loose and there is no canned magic that will stop overheating in that situation. If you've gone 500 miles and you're not using coolant or overheating I'd say you're clear and the job was done correctly. Enjoy.

Conventional wisdom here is that there is no 'stop leak' product that would delay N* headgasket issues any signficant period of time. Never seen a post that anyone said they had any success trying that. When N* HGs go they tend to pop the headbolts loose and there is no canned magic that will stop overheating in that situation. If you've gone 500 miles and you're not using coolant or overheating I'd say you're clear and the job was done correctly. Enjoy.

Thanks, that lays it out for me. I've put on about 750 miles so far, and no overheating.

My own mechanic was checking it over for me and found a small coolant leak at the thermostat gasket, which I haven't repaired yet, wanted to see what happens with the car/HGs first. So, after 750 miles I added maybe 1/2 a cup of coolant, maybe a bit less. I did see a bit of steam at one point near the thermostat housing, but other than that, no leaks on the garage floor.

One thing that bothers me is that the heat has stopped working...first it was sporadic, on and off (fan always blows tho)...now it seems to make lukewarm heat when driving but the air goes cool at stops when idling. Felt the hoses going to the heater core, one of the hoses is hot but the other is just warm. Tried running the car for a while with the surge tank cap off, but no dice. No bubbles in the surge tank either. Temp gauge is always at 12:00 after warming up. Checked for codes, there are none, history or current.

Any ideas?

Thanks again, let me know if this should be in a new thread....

The Northstar cooling system has quite a few twists, turns, and low-flow spots. It may take a while to get all the bubbles out here and there. Make sure the purge line from near the thermostat housing to the surge tank is free and clear and spits water into the surge tank. Pull the line off at the tank (careful: don't crack the tank nipple), have a margarine tub handy, start the car cold, and you should get coolant flow into the tub. If you do, let it bleed for a short while: the big line at the bottom of the tank will replenish any lost coolant - and then shut down and clamp it back on the tank nipple. refill only to the halfway line on the tank.

The Northstar cooling system has quite a few twists, turns, and low-flow spots. It may take a while to get all the bubbles out here and there. Make sure the purge line from near the thermostat housing to the surge tank is free and clear and spits water into the surge tank. Pull the line off at the tank (careful: don't crack the tank nipple), have a margarine tub handy, start the car cold, and you should get coolant flow into the tub. If you do, let it bleed for a short while: the big line at the bottom of the tank will replenish any lost coolant - and then shut down and clamp it back on the tank nipple. refill only to the halfway line on the tank.

Ahhh see what I did was just pull the purge line and make sure it was flowing free, which it was...but then I just plugged it back in.

I will try that tomorrow...how long should I let it bleed, by short while do you mean 2 minutes, or less?

Should I always only keep the level in the surge tank at half way, not the cold full line?

And finally...do you think this is just air in the system and after doing the above, I'll be ok? Or should I get the heater core flushed, or the entire system flushed?

Thanks sub...you've already been a ton of help through your previous posts to others that I found doing searches.

Bleed it until you worry.........but don't run the surge tank dry. ............Cold fill line cold.

Those ^^ are the most obvious, easier fixes. When you get to the radiator shop/dealer flushes with a machine, that's a different ball game. Not saying that's bad, just exhaust the easier options first (and less expensive.).

Ok thanks again..I will post back with my results.