: Northstar head gasket failures



Eldorado guy
08-01-08, 01:46 AM
Hello. My '80 Eldorado is a beautiful car and was running perfectly (for once) as a daily driver, but it caught fire and it is back out of commission. I will fix it, but due to the massive amount of problems that I have had with it since I got it at 13, I will be getting another car. I would like to purchase a 1994-1997 Seville SLS or STS or even another Eldorado from that same period. I know that I will be running premium and I should be getting around 20 mpg (my foot isn't real heavy).

I was told that the head gasket problem was mainly in 1998-2002 cars, which is why I'm looking at 1994-1997 models. Did this effect all years? What is the likelyhood that I will have a head gasket failure? That's my only real concern. Cadillacs with Northstars are everywhere, so they must be a good engine. Can you give me any advice on how to tell if one has this problem? I'll be looking at Cadillacs with around 60K-70K miles on them. Any advice is appreciated!

Thanks everyone,
Danny

ejguillot
08-01-08, 02:15 AM
I think you were misinformed about the affected years. 1996 to 1999 are the worst, 2000-2003 are better (GM changed the head bolts, making some longer), and 2004-up are better still (Another head bolt change).

For any N* Caddy you want to buy, be sure and do a test for combustion gas in the coolant. You can buy a test kit from various auto parts stores, NAPA included.

2000 N* and up take regular gas, but the 1999 and prior are said to be a little peppier. 1995 may be your best bet, as those were still OBD I.

Eldorado guy
08-01-08, 02:53 AM
Ok. I became pretty fond of the older styles too. I was really interested in this one:

http://sfbay.craigslist.org/eby/car/776385795.html

So, what did they do to make the 96-99 different from, say, a 95? If I was to shop around, I could probably afford a 2000 Seville....

misfit6794
08-01-08, 11:20 AM
When it comes to hg's its a real crapshoot, unless you have documented coolant changes every 2 years, and even that doesn't make them immune. I personally would do the test described above on any potential purchase. Worst comes to worst you buy a nice low mileage caddy for cheap, and then put 3500 into fixing the motor.

Also be aware that the sts uses extremely expensive (1000 a piece) shocks, the sls uses conventional ones.

Eldorado guy
08-01-08, 08:17 PM
Ok. Pulling cylinder heads isn't new to me so I'm sure I could handle it, but I don't want to. Are these engines guaranteed to have this problem, or do only some have this problem? Basically, I am wondering if it's just going to be a matter of time or what. I feel that it would be foolish for me to buy a car that I know will blow a head gasket sooner or later. I absolutely love Cadillacs, but I can't just keep buying them and spending thousands on repairing them like I have with the Eldorado. That's been one crazy $8,000 journey......

I greatly appreciate the help,
Danny

Ranger
08-01-08, 08:45 PM
Are these engines guaranteed to have this problem, or do only some have this problem?
Of coarse not. Pre 2000's are more likely, but certainly not guaranteed. On the other hand, there is no guarantee that they won't.

tateos
08-02-08, 10:36 AM
I had a '97 that blew a HG at around 100K miles, I replaced it with a used '97 engine and that engine blew a head gasket at around 100K miles. You can draw your own conclusions. I think the 2000 and later engines have a better track record.

BTW, to repair a bad HG on these engines, you don't just pull the heads - first you drop the entire cradle with engine and trans and steering rack attached, THEN you pull the heads, then you drill and tap and install inserts into the cylinder bolt holes in the block, then you reassemble. That is what I did when the second engine's HG failed. It's not really that hard, but it is a LOT of work.

Ur7x
08-02-08, 11:01 AM
And good luck getting 20mpg in town... Premium, regular, plutonium... it doesn't matter... With the A/C off a strong tail wind and only driving down hill you will get 18... IF You are lucky...

In constant city stop and go driving with the A/C on auto these cars don't deliver much over 16mpg... driven hard 15 or less....

These car mileage SHINE on the highway with numbers in the high 20's...
But in town NO 4000 pound car is going to get great mileage...

If you are worried about HG the advice above is good and relevant...
1) Have it tested
2) Check and Change the coolant OFTEN
3) AVOID 1997,1998, 1999 cars and
4) Buy the newest car, low mile car you can afford... If I was shopping for an Eldo... 2002 baby!

What ever you buy make sure its coolant has been serviced OFTEN
My 2002 gets fresh coolant every other year.

Eldorado guy
08-02-08, 06:47 PM
Thanks for the advice, everyone. Wow, tateos. That's a lot of work! I don't want to do that.

Don't worry, I didn't expect 20 in town. Sorry, I shouldn't have just said "around 20 in town." I do around 70-80% hwy and the rest is in town. I took my time accelerating with my Eldorado, when it was in operation. It got me 14 once. It liked to get 12.5. When I got it, it got 8 :banghead:. On the hwy, it could get 20, believe it or not. Basically, I will probably do 65-70 on the freeway and I will take it easy in town. What numbers are you guys seeing?

Submariner409
08-02-08, 07:28 PM
Late Northstar cars....after 1999....

STS, 3.71 final, town 14-18, depending on every condition. Highway, 24-26
SLS, 3.11 final, town, about same, Highway 25-28

Eldorado, a bit better, but not much, all around.

Every driver, car, location, altitude, gas used.....all different up and down. Don't hang your hat on any one set of figures......they all change with the phases of the moon, the heat of the meat, and the mass of the a.......

Krashed989
08-02-08, 07:41 PM
After owning my eldo, I would not get a car with an open deck aluminum block engine. After 2003 they started making the N* engines with closed decks (Or so I've heard anyways) which is a lot better because it doesn't bunch the head-gasket into the water-jacket like open deck engines do over time.

Ur7x
08-03-08, 02:27 AM
You might want to double check that as far as I know ONLY the Supercharged NorthStars have closed decks... The rest of them are open.

Eldorado guy
08-03-08, 05:29 AM
So definitely stay away from this guy?

http://www.hanselcadillac.com/vehicle_results.php?SRID=1G6KS52Y6VU818547

Damn, only about 68,000 miles, serviced right there at the dealer all it's life, and properly maintained (supposedly; yes, that is what the 'dealer' said, whom I wouldn't trust. I would want some kind of records, if possible. I really, really liked this car, it just smelt like an ash tray. I can't have that. I know that they can eliminate that with some sort of machine, but I forgot what it was called. I've smelt the before and after when using those and all I can say is wow! I could probably get the car quite a bit cheaper too, as they've had it for a while. It started at $10,991. It actually isn't $7,995, it's $6,995.

Submariner409
08-03-08, 09:13 AM
If the vehicle has been serviced at the dealer "all its life", then they won't mind running the VIN through the GM Service History database and furnishing you a copy. That will show if every recall, warranty, and dealer maintenance item is there as they say. It should also show if the engine was ever repaired due to coolant loss/blown headgaskets.

Ur7x
08-03-08, 10:20 AM
If you are a non-smoker it is next to impossible to get the smoke smell out of a car...

I had success once... I took the ENTIRE interior apart... piece by piece and washed them in the bath tub (kiddy pool for the really big stuff)... if anyone saw wow much brown crud came off of each piece they would never smoke again.

The OZONE machine you are talking about will provide a temporary fix... but it will take several trips (at least four) before the smell is gone... if you (or some one in your family) is allergic to cigarette smoke plan on about 5 or 6 treatments

Submariner409
08-03-08, 11:35 AM
Like Ur7x said, cigarette smell is darn near impossible to remove, and then it takes heroic effort. If you can do the ozone treatments, go for it, and use that as a bargaining tool. Or, negotiate a dealer cleaning until you're satisfied.

I'm a reformed smoker, cold turkey from 3 packs of Marlboro a day in '80, and now the smell of a smoker's home or car is enough to gag a maggot.

Eldorado guy
08-03-08, 09:01 PM
Ok, thanks. I'll surely stay away from the smoker car. I have trouble breathing in casinos, so think about what it would be like if I was in a closed car. How about this one?

http://sfbay.craigslist.org/sfc/car/781250604.html

I remember some saying that the 1996-1999 years or so were the worst, so what is the likely hood of this one giving me trouble? This one is a non-smoker, supposedly. My friend Mark, who has been helping me with my n* decisions, has a 1995 that has 189,000 or so on it. No head gasket problem yet. Sorry to throw all these cars out to you guys, I just want to avoid the head gasket issue as much as possible. What makes the 1995s different from the 1996s?

Thanks everyone,
Danny

hueterm
08-03-08, 10:04 PM
So definitely stay away from this guy?


I'd definitely stay away from those wheels and tires...

Eldorado guy
08-04-08, 12:20 AM
Check this out:
http://www.100megsfree4.com/cadillac/cad1990/cad95s.htm

If you look at the engine information, you will see that the engine is composed of an aluminum block and aluminum heads.

Now, check this out:
http://www.100megsfree4.com/cadillac/cad1990/cad96s.htm

In 1996, they switched over to an aluminum alloy block with cast iron heads.


Could this have anything to do with it? I have a book that says aluminum on aluminum for all these years, so........ Does anyone know anything about this? From what people have said, the '95 and earlier cars are less likely to have this problem, but why?

Submariner409
08-04-08, 09:49 AM
Your second source (1996...) uses incorrect semantics in referring to "aluminum block with cast iron liners and cylinder heads".

All Northstars are aluminum block and heads, with cast-in liners. (Go back a year or so in Northstar Performance and look for pictures of AJ's 2001-2002 (?) cylinder heads for his Fiero engine work, as well as other members' overhaul pictures.......aluminum.)

1996-1999 experienced casting porosity in the blocks, leading to coolant intrusion into the head bolt cavity by either direct seepage or by the lack of head bolt clamping pressure due to a poor thread retention in one or more bolt holes. The coolant, over time, reacted with the aluminum/steel bolt interface and destroyed the bolt hole threads. Slight changes in metallurgy, gaskets, bolts, threads, and assembly procedures mostly alleviated the problem after 2000+. The mid-late-90's units seem the most prone to failure, while the 2000+ has a generally good track record, but there are exceptions.

My personal opinion is that an open-deck design is inherently weak in the surrounding cylinder gasket retention area, unless you O-ring the liner top with either copper or s/s.

Eldorado guy
08-05-08, 01:24 AM
Submariner, thank you for your help. Thank you to everyone, you guys have been a big help. I apologize for all the questions, I was just wanted to make sure that the '95s engine should be more unlikely to obtain a head gasket issue than say, a '97.

Submariner, was there a service bulletin that said that or something? Where did you hear of that? How does everyone know about the 1996-1999 engines and that specific problem? Thanks.

Submariner409
08-05-08, 07:52 AM
Not sure if GM ever acknowledged the headgasket problems directly by issuing a TSB. If they did, that would indicate that GM recognized some fault in design or manufacture, which could open them to incredible warranty/lemon law pursuit.

I'm not being flip, but if you take the time to go back and search every Seville, Deville, and Northstar Performance page you'll get a pretty good picture of what years have the most problems and failures to date.

Cadillac is not the only maker plagued with mechanical problems, not by a long shot. If you haunt practically any other automotive enthusiast site you'll find the good, the bad, and the ugly about any car.

Ur7x
08-05-08, 11:45 AM
Submariner, thank you for your help. Thank you to everyone, you guys have been a big help. I apologize for all the questions, I was just wanted to make sure that the '95s engine should be more unlikely to obtain a head gasket issue than say, a '97.

Submariner, was there a service bulletin that said that or something? Where did you hear of that? How does everyone know about the 1996-1999 engines and that specific problem? Thanks.

Read the sticky poll results at the top of this forum

97/98/99 are the worst of the worst and 97 is the worst of those

Buy a 2000 or newer.

misfit6794
08-05-08, 04:03 PM
The only way to be sure of avoiding hg problems is to avoid the northstar altogether and get a caddy with the 4.9L.

Ur7x
08-05-08, 08:02 PM
The only way to be sure of avoiding hg problems is to avoid the northstar altogether and get a caddy with the 4.9L.

The 4.1, 4.5 & 4.9L engines are not immune to head gasket issues either...

Google "Cadillac 4.9 head gasket" and you find lost of victims... The reason everyone likes the 4.9 was because it has way fewer failures then the 4.1... Just about every 4.1 failed over the years. But way fewer is not zero.

Edahall
08-05-08, 08:27 PM
The 4.1, 4.5 & 4.9L engines are not immune to head gasket issues either...

Google "Cadillac 4.9 head gasket" and you find lost of victims... The reason everyone likes the 4.9 was because it has way fewer failures then the 4.1... Just about every 4.1 failed over the years. But way fewer is not zero.

Most 4.5/4.9 head gasket failures are due to misdiagnosis for bad intake gaskets.

Eldorado guy
08-06-08, 12:16 AM
Read the sticky poll results at the top of this forum

97/98/99 are the worst of the worst and 97 is the worst of those

Buy a 2000 or newer.


That's what I was doing, but how many people have, say, a '97 compared to how many have a '95? I haven't been around here much, so I don't know how many 95s there are and how many 97s there are. What it 60 people on this forum, who have reported it, have a '97, and say that 5 have a 95? That's what I was wondering.

Submariner, I will do that. I will check to old posts. Maybe that will answer my other question in this post.

Submariner409
08-06-08, 09:20 AM
Eldorado Guy....Don't lose sight of the fact that practically no one comes into a Forum such as CF to tell you how good their car is. You come here to find out how to fix some problem.

It's impossible to calculate just what percentage of all owners of a specific engine or model vehicle come to an Internet Forum, but it must be a pretty small part of the total product on the road.

Our GM Techs see and occasionally report on other failures in their shops, but the total is still a very, very small percentage of the whole. We see nothing but problems, so the perception is that the sky is falling.

Actually as complex as a modern automobile has become, it's a wonder it runs at all !!

Eldorado guy
08-06-08, 07:08 PM
You know what, Submariner? You are right. I seem to loose sight of the fact that I am on a forum for HELP with PROBLEMS that THEIR car has. From what I have gathered, it could happen to me, it could not. I guess I can fix it myself if it does.

With that said, on Sunday I am going to go and look at this car:

http://www.autotrader.com/fyc/vdp.jsp?ct=u&car_id=248861404&dealer_id=566852&car_year=1995&model=SEV&num_records=25&systime=&make2=&highlightFirstMakeModel=&start_year=1994&keywordsfyc=&keywordsfyc=&keywordsrep=&keywordsrep=&engine=&certified=&body_code=0&fuel=&awsp=false&search_type=both&distance=100&marketZipError=false&search_lang=en&showZipError=n&make=CAD&keywords_display=&color=&page_location=findacar%3A%3Aispsearchform&min_price=&drive=&max_mileage=&style_flag=1&sort_type=priceDESC&address=95492&advanced=&end_year=1995&doors=&transmission=&max_price=&cardist=85

It's a little pricey, but I may be able to bargain a bit. These aren't really selling well here, due to gas prices. It only has 65,000 miles.

Submariner, do you work in the service dept. at a dealer or something? Sounded like you are! Is there anyway to see the service history on the car? Carfax says that it has been in for numerous normal maintenance services, but also for the A/C, suspension, and twice for the engine. I don't know what was done, and I'm curious.

I'm just really looking forward to a car that doesn't need a once a week repair. Hopefully this one will be good!

Thanks for your help,
Danny

Submariner409
08-06-08, 09:21 PM
Take your VIN to a Cadillac dealer on a quiet Wednesday or Thursday afdternoon.....ask them to run it through the GM system to recover the warranty, recall, and GM service work done on the car.

I spent a good part of my high school years working in various dealer parts and service departments both full and part time. Washington, DC car parts runner. Also worked as a Jaguar/MG/Hillman/Morris mechanic at a small shop in DC. Raced MG, Jaguar, Austin Healey cars, Triumph and Bultaco motorcycles. Built Chevy 283 and 327 "upgrade" engines for a DC dealership. 25 years in submarines from diesel boats through fast attacks to ballistic missile boats. Chief of The Boat on 2 missile subs. 11 years as Master of a 2300 SHP Oceanographic Research Vessel. Lapsed Private Pilot; multi engine recip, Navy rare gas diver, yacht delivery skipper, 3 of us do Olds and GM big-block engine rebuilds for boats, never lost interest in things mechanical, still haunt machine shops, boat builders, classic car rallies, and take great delight in STS stomping the snot out of the local high school ricers. Gun collector, target shooter, deer hunter, reloader. Been there, done that. If it clicks or makes power, I love it. :sneaky: So does Karen.....

tateos
08-07-08, 10:08 PM
Eldorado Guy....Don't lose sight of the fact that practically no one comes into a Forum such as CF to tell you how good their car is. You come here to find out how to fix some problem.

It's impossible to calculate just what percentage of all owners of a specific engine or model vehicle come to an Internet Forum, but it must be a pretty small part of the total product on the road.

Our GM Techs see and occasionally report on other failures in their shops, but the total is still a very, very small percentage of the whole. We see nothing but problems, so the perception is that the sky is falling.

Actually as complex as a modern automobile has become, it's a wonder it runs at all !!

Hey Sub - you are right that most people end up here looking to solve a problem, but don't you think the poll is still valid because it is a poll of people that have come here with ANY problem, not just HG problems?

Ur7x
08-07-08, 10:23 PM
The poll has some issues, but it is a good indication that something is wrong with the pre 2000 cars... There are a few challenges with the poll

It assumes the same number of cars were sold each year... If they sold double the number of Northstars in 1999 then 2000 then that could explain some of the massive drop in issues in 2000... The other challenge with the poll is that it assumes that all Northstar gasket failures will get repaired... This too is problematic.. if you own a high mileage 1993 STS the cost of just the timeserts, bolts and gaskets are just-a-bout worth more then the car... No-one is going to fix one of those... They are just off to car heaven. So it is unlikely that those will get reported...

But that aside the poll, and insider reports support, that 2000 and newer cars are WAY LESS likely to have a HG issue... NOT ZERO... but a lot less.

Eldorado guy
08-08-08, 01:09 AM
Wow, Submariner! What a life! You have had some very interesting jobs. I actually just got through my Aero 50 class and passed, so now I have to take the FAA test. I get high school credits for this class, which I needed. Sometimes I have trouble paying attention at school, so I found that drawing something can help me listen to the conversation. I sometimes draw engine designs. They probably wouldn't work, but they are cool to think about! I've always loved cars and engines, as the fascinate me.

You've had some very cool careers. I'd love to be involved in those. I've imagined the look on a ricer-driver's face when he gets beat by a heavy Cadillac. You wouldn't know they have power!

Thanks,
Danny

Submariner409
08-08-08, 09:56 AM
tateos, Of course the poll is valid......Wasn't there a troll who attempted to weight one or two years for stupid kicks?? Anyhooo......the more entries the more credibility the poll has.

If some work, say head gaskets, was done at a GM dealer, there's a specific repair code assigned to that job. I'll bet that some database in the sky has a tally of all the Northstar head gasket reports. .......but we'll never see it !

tateos
08-08-08, 01:40 PM
I think having my head gasket fail and then repairing it myself was one of the best and one of the worst experiences, both at the same time. I was never in the military, but I think maybe it is like going to war, and coming back unharmed and living to tell about it. I have done engine jobs before but never one that was this complex and challenging.

DHspring
08-12-08, 11:27 AM
I had a 96 Deville with 127,000 miles that blew a head gasket, according to the local mechanic, who did the compression test in the coolant, they said it was 100% sure a head gasket. Rather than fix it, I traded for a 2005 STS with N*, glad I did, I'm finding the 96 to be in the "trouble years". No way was I going to let a local yokel shop fix an engine like that in their small shop. Out of sight, out of mind, got a good deal on trade. There's another data point for a 96 N* head gasket.

DHspring
08-12-08, 11:30 AM
I think having my head gasket fail and then repairing it myself was one of the best and one of the worst experiences, both at the same time. I was never in the military, but I think maybe it is like going to war, and coming back unharmed and living to tell about it. I have done engine jobs before but never one that was this complex and challenging.

Man, this sounds like a marriage, "best and worst experience", you love and hate your wife at the same time.