Head Gasket liquid sealer

[Gyounker]

Since I am in an engine replacement situation for my 98 Eldorado, it was mentioned there is a liquid additive that sometimes works for sealing a bad head gasket. I forget the product name but I am told it is used by dealers on used cars and buyer-be-aware, but it can work.

Has anybody ever used this product? It could be a $200.00 try before/in lieu of a $2000.00 engine replacement.

[Ranger]

It's called Thermogasket or Heal-A-Seal. It won't work. The gasket is leaking because the threads are pulled. You have to repair the threads with Timeserts.

[Bruce Nunnally]

Here was the previous discussion

The last posts seem to document Ranger's comments.

This tends to be a very emotional topic.

[MrEldo97]

Don't waste your money. It's not the headgaskets leaking, but the head bolts have pulled out of the block.

If you're replacing this engine with a used engine be sure to have the block in the used engine Timeserted

or you'll most likely have the SAME PROBLEM WITH THE USED ENGINE after install.

IMO, I wouldn't advise that anyone buy a pre-'03 Northstar Cadillac because of the problem with headbolts pulling out

of the block.

[Gyounker]

I did read the long thread and it seemed like it might work if the bolts are not pulled. I wonder if the people last year are still driving the "fixed" cars or if they went bad again. I think I am trying to remain optimistic that something "could" work. Generally shortcuts never work.

[MrEldo97]

I did read the long thread and it seemed like it might work if the bolts are not pulled. I wonder if the people last year are still driving the "fixed" cars or if they went bad again. I think I am trying to remain optimistic that something "could" work. Generally shortcuts never work.

The bolts ALWAYS PULL. It's as certain as the sun coming up in the morning.

Don't delude yourself, don't waste your time looking for lower cost repairs, don't ask me how I know...

Seriously the head blots pull the threads right out of the block.

To prove it to yourself remove the cam covers (do the rear head first, most likely to have pulled bolts) and test the tightness of the headbolts. You'll find them all loose to one degree or another. When the bolts in my '97 Eldo pulled; 6 of the 10 bolts in the rear head I pulled out with my fingers. Give your car the same test...

Good luck.

[Gyounker]

Pulling out head bolts by hand---now that is scary.

My 98 has been sitting in the driveway for about 3 months waiting for my attention. I have been finding other people locally that have had the same trouble with their Cadillac's. Is this some kind of an epidemic?

It was mentioned to me that the motors are designed to last 6 years and then you are to buy another Cadillac. Is this a throw-away motor?

It is a great looking car even though it sits idle in my driveway. Now what??

[MrEldo97]

Timesert the block and drive it. Or install a used or reman motor that has been Timeserted and drive it.

Epidemic...could be. Awhile back I heard that this problem with pulled headbolts in Northstars affected about 20% of the cars on the road. IMO as these cars age and accumulate miles the incidence of pulled headbolts increases. The Northstar is an excellent world class motor, though this head bolt problem is cause for concern. GM has made improvements in this area over the years and hopefully the '03 and later Northstars will avoid pulled headbolts. Time will tell, but "once burned, twice cautious".

I always advise folks to NOT buy pre-'03 Cadillacs unless the seller proves that the block has been properly Timeserted.

My Timesert repair is now 18 moths and 20K miles old and my Eldo runs better than it did when it was new...I was sitting in my driveway last night (havin' a cold one) looking at it and thinking what a good looking car it really is.

My other ride is a Jaguar XJS with the AJ16 6. Same set-up re the head but NO history of pulled headbolts in that motor. So clearly GM took manufacturing short cuts or made design errors in the Northstar.

[BodybyFisher]

NO, its not an epidemic, NOT even close. The internet tends to be a focal point of people with problems, you don't get owners coming here saying how great their Cadillacs are performing. These engines are very sensitive to proper maintenance, if you buy an engine that has not had its coolant changed and it became acidic or lost its corrosion package it will damage the head gaskets and get into the head bolts and corrode the threads. Buying a used Northstar it is extremely important to know its maintenance history. I WOULD buy a 96 and newer Northstar IF I knew it had its coolant changed on time and if WOTs were done regularly.

We have done a survey of head gasket problems and found that 15% of our membership has had problems, see this poll, 15% is NOT an epidemic. Can you find Northstars out there that have had problems?, Yep, many of us look for them, do you know their history?, Nope. All I would say it be careful buying a Northstar.

http://caddyinfo.ipbhost.com/index.php?showtopic=4942

[Bruce Nunnally]

I have not seen factual data that suggests that all or most or even many Northstars will eventually have head bolt issues.

There is a popular concept that all cars SHOULD last forever with no maintenance or repair. I know that is attractive, but it is not a reasonable expectation.

I would only recommend a 10+ year old vehicle of ANY type to someone if they either had expertise in vehicle maintenance and repair or had a good mechanic. At the very least they need a backup vehicle.

[KHE]

Remember that even though 15% of the members on this board have had head gasket issues, that doesn't translate to 15% of ALL Northstars have head gasket issues because of the reasons BBF listed.

My '96 SLS with 128,000 miles on it has not had any issues - I have maintained it per the proper maintenance schedule since purchasing it with 56,000 miles on it at four years old. Having said that, I hope it doesn't blow the head gaskets next week...

I'm on the lookout for a black on black '99 Deville with bad headgaskets that I can buy cheaply... I found one a couple of months ago near Louisville but the seller wouldn't answer any of my emails so I didn't pursue it.

[BodybyFisher]

I was thinking of what Kevin was saying before while I was out. This is true, again, this board is a focal point of Cadillac owners who are into performance, DIY, fixing problems, etc, I think that the 15% sample here would be higher than a sample of the entire population of Northstars.

My 96 has 114K on it, its coolant has been changed lots of times. I don't want to jinkx myself but, its still running great. There are MANY NSs out there with very high mileage on them. About 44% of Northstars have over 100K miles, look at this odometer poll >> http://caddyinfo.ipbhost.com/index.php?showtopic=606

EVERY time the shuttle takes off, I think about the ORINGS in the solid booster rockets.. Everytime it lands I hold my breath because of the tiles and potential damage from foam strikes. Its human nature.

BUT, when I was a kid, engines rarely made 125K and when they did limp over 100K, you sent it to the junk yard. If a Northstar gets 100K and for $3000 you can get another 100K out of it, I see that as acceptible. These are very high performance engines, keep in mind that its 281 cu in and putting out 275 and 300 hp. That is like a 427 putting out 456 HP stock... the three two barrel 427 put out 435 HP.. and it would break your neck. Those types of stresses and the high compression of the NS require the engine to be maintained well, and if not it breaks down.

[sucker4caddys]

just used thermagasket in my 99 seville seemed to have stopped the overheating problem but still had pressure in the surge tank. seems to be a band aid but definetly worth the 140 i paid and has a moneyback warranty. lasted even on 2 hr drives.

[BodybyFisher]

just used thermagasket in my 99 seville seemed to have stopped the overheating problem but still had pressure in the surge tank. seems to be a band aid but definetly worth the 140 i paid and has a moneyback warranty. lasted even on 2 hr drives.

OK, Labor Day Weekend, I want you pack your car with luggage, your kids and your wife, to get on 95 south in 100 degree heat, I want you to leave late, so that you catch the traffic, and get stuck in 60 miles of bumper to bumper traffic on the Jersey Turnpike then open it up to 75 for the remainder of the 5 hour trip to and report back your results. I can't wait. Make sure you have AAA towing, "just in case". If your magic elixir passes that test, I am sold.

[95SevilleSLS]

I've had 4 northstars, all but one had over 150,000 miles and only one had a headgasket problem, but it was NOT because of pulled head bolts. It was due to it being severly overheated and it destroyed the headgasket. I live in a town where there are a LOT of Cadillacs and I have never heard one person mention having a bad headgasket. The first time I ever heard of it was when I came on here.

Like others were saying, this forum is mostly for people talking about their problems and only 15% of those people have headgasket problems, which isn't very much if you consider all the people that are coming on here due to problems.

I wouldn't be hesitant to buy any northstar no matter what year it is and how many miles.