Advice on Blown Head Gasket?

[randinator0702]

I just recently aquired a 1997 Cadillac Deville with a 32valve 4.6L Northstar engine and i know i have blown a head gasket i have run a pressure test and a spark plug test and i know from all of the problems that it is one so if anybody has any advice on what to do it would be greatly appreciated thanks

[jkennedy293]

If you have a blown head gasket, I would start by figuring out which bank it's on, and get it replaced. If you have a shop do it, its going to be pricey. If you do it yourself its going to be difficult and time consuming.

[2002 Caddy]

Head over to Cadillacforums.com or Caddyinfo.com

And read the HORROR that is the 97/98 & 99 Norhtstar head bolts/gaskets...

No one knows why (or if the do they aren't talking) but GM has a MAJOR issue with pre 2000 Northstars with 97/98/99 being the worst of the worst.

If the coolant isn't maintained PERFECTLY (or even if it is) the steel head bolt react with the soft aluminum block... the block basically DISSOLVES/Disintegrates and the headbolts pull out... It is not the gasket that failed it is the head bolts...

Again no one knows but my bet is that GM reduced/eliminated the amount of block hardening they did in 97 after they had finished the switch to Dex-cool (which is easier on aluminum parts then the green silica based coolants)... We are not sure if this is the case, but we do know for sure that these blocks are as strong as a block of cheddar cheese and its only a matter of time before the head bolts pull out... (most go right around 90,000 miles)...

Oh but wait, it gets worse. To fix this you have to lift the entire car OFF OF the engine... and then you have to drill, re-tap and insert specially designed steel inserts called "timeserts" or Normserts or Bigserts. then you replace the gaskets torque it all down and hold your breath... (gone are the days when you and you neighbor could replace head gaskets for $80 in your drive way with hand tools and a six pack)

If you escape with a bill less then $4,000 consider yourself VERY lucky.
The 97/98/99 Northstars share head bolts from another "infamous" engine... the Quad 4...With similar results... These are short fine thread bolts that once removed yield a damaged block that MUST be repaired.

Of course GM knew about this problem... and In 2000 the replaced the Quad 4 bolts with (are you sitting down)... yup... LONGER Quad 4 bolts... these bolts work a little better and the 2000-2003 Northstar have gasket failures at about 1/10th the rate of the REALLY bad years... But still WAY too many for GM's flagship cars and flagship owners.

Not to worry.. In 2004 GM looked at the bolts again and this time got it right and the Northstar uses a bolt that has a similar pitch and length to the famous LS1.... Bolts... and Bolt/Gasket Failures in 2004-present Northstar are pretty much non-existent.

There is a firm in Ontario Canada that will replace the bolts on 97/98/99 Northstar with head studs and provide a permanent repair... I believe they charge something in the range of $2000 and guarantee there work for a year or two... If mine ever go, I will be looking into that option.

The sad fact is that this will probably effectively total your car... Most dealers will charge 4500-5000 and your 97 Deville is maybe worth $6000. Spending $5000 fixing a car worth $6000 is a tough call...

Sorry, and good luck.

[shadams]

Oh no, I was going to bring that up, but thats to 2002 Caddy for giving all the details. We have 2 Ex Caddy techs that get all the Cadillacs that come in for this. It is a nightmare and we usually end up just swapping out engines with beefed up heads. Good luck...

[2002 Caddy]

Oh no, I was going to bring that up, but thats to 2002 Caddy for giving all the details. We have 2 Ex Caddy techs that get all the Cadillacs that come in for this. It is a nightmare and we usually end up just swapping out engines with beefed up heads. Good luck...

There is a machinist down the street from a large Cadillac dealer in my city... I was talking with him about a year ago... He told me that at one point he was timeserting 2 or 3 blocks A DAY (10-15 a freaking week)... the dealership would out source the work to him since too many techs would screw up this procedure as they would try to beat the book rate.

The really sad thing here is that it took GM over 10 years to fix this engine. I wonder how many Cadillac buyers are lost forever... I know three people with a 97/98 or a 99 car two of them have had headgaskets go. On fixed the car, one "scraped" it and one is holding his breath...

None will ever buy a Caddy again...

[shadams]

Wow! Well, we have done 4 or five, but we arent even a Caddy dealer. Out of those only one of them we timeserted and it is still going. There others we just swapped out engines as the customers wanted the full warranty 3/100k.

[Mahoot]

I just joined this forum my customer sent me the link cuz he has a 97 Caddillac DeVille with 120k on the odo and the oil looks like chocolate. I really didnt want to break the news to him because its a NORTHSTAR engine... yeah i know, i know. Ive been turning the wrench for over 20 years and there aint nothing that cant be fixed. But there's always a break point of going ahead or scuttling the ship. So far everything ive read says this ones' gonna be a nightmare. Your post is one the clearest and most concise ones ive read. But ive got one question that will be the determining factor: Can the TIMESERTS be done with the block inside the car? Im going in through the top to remove the heads and tap out chase the threads. Using the force im inclined to say you cant drill the block cause the block is at an angle and there probably isnt enough room at the back side to get at them adequately. Am i on top of this or is this reasonably do-able. Ive never done a Northstar engine before and most everybody ive talked to locally says proceed at your own risk and DONT guarantee the labor. Tell your customer up front they are taking a very expensive gamble. Oh, one more thing what's your opinion on THERMAGASKET particularly for the Northstar engine?

[2002 Caddy]

No and no

Themagasket will only plug up the heater core (or something else) and will make things WORSE... Thermagasket has been PROVEN NOT to work with NorthStar problems (there is NO magic bullet here)

One or two daring FIYers have tried to Timesert the engine with it in the car... It can be done, but all agree that it would have been easier to remove the engine rather then attempting this ...

Keep in mind that in order to gain access to the rear bolt holes you will still need to loosen the engine cradle and use a jack or what have you to tilt the engine forward an inch or two.

You really need to take the engine out of the car... or more precise take the car off of the engine.

One tip that I have heard most dealers are going is to upgrade the block to 2004 bolts... Buy the inserts for a 2004 block (long coarse threads) and then buy the 2004 head bolts.. the 2004 and newer NorthStars with the better bolts do not have this head gasket problem.

If the car in question has a crank case full of Chocolate Milk Shake... you will want to replace all of the lower bearing and half case seal... This requires Re&re of the motor.

Yet another option... this company also offers a permanent fix Head STUDS!
Head studs

The challenge with the studs is this guy is in Ontario Canada and you have to arrange to get the motor to and from him... Though if you drop of the car they will do the entire job for $1500... which is about 1/3 of what you can expect at the dealer...

[69nova]

Wow!
I read the thread out of mild curiosity but 2002 Caddy's diagnosis and solution left me cold. I thought the NorthStars were bullet proof and the one reason people (mostly my age) by Cadillacs is for ride comfort and reliability. And, as I read, GM kept the problem quiet rather than owning up to it so as not to lose customers.
I rebuilt the V-6 motor in my 89 Caravan (at 175,000 miles) in my garage and it took about 2 weeks (during my spare time) although this car is simpler and easier to work on. The symptoms were the same-the oil looked like foamy chocolate. I had nothing to lose since I would have junked the car at that stage.
There is only one reason why coolant gauges are on your dash boards- aluminum heads and aluminum blocks. Unlike my 73 Grand Prix that lost a hose and the motor seized on the highway, these new cars self-destruct. With my Grand Prix, I had it towed to the nearest garage, the hose repaired and I was on my way again. Overheat an aluminum and it has a good chance of being warped.
Aluminum has 1/3 the weight of steel but also 1/3 the strength (Young's Modulus) of steel. I would think that any hardening measures and inserts are probably on the design's limits.
Another reason why I chose the 04 supercharged motor in my Monte, an iron block and iron heads.

[tmasayukih]

Hi i got a 2002 cadillac deville with a blown head gasket i read this tread and saw shadams post what kind of motor would u recommend putting into this car instead or what do u recomend i do i live in hawaii and shipping it to canada is out of the question what would be the cheapest and best way to go out this

[sonjaab]

There is NO cheap way ! Dump the car !

[2002 Caddy]

Hi i got a 2002 cadillac deville with a blown head gasket i read this tread and saw shadams post what kind of motor would u recommend putting into this car instead or what do u recomend i do i live in hawaii and shipping it to canada is out of the question what would be the cheapest and best way to go out this

Aloha,

The ECU/PCM on these cars are very finicky to the motor under the hood. You will need to find another 2000-2004 motor of the SAME power rating (Vin Y or Vin 9)

The Canadian company will sell you the head studs as a kit and you can install them yourself, but as I noted above this will require a complete re&re of the car off of the engine cradle.. (for someone who has done this before with the specific tools and a lift expect a book time of 12-14 hours) for a backyard warrior with a 2 ton cherry picker engine hoist... expect a week long effort of skinned knuckles.

Pomaika`i

Which Island are you on?

[tmasayukih]

thx for the help i have a guy who worked for caddy who quoted me 16hrs or so for the labor. do you know the website for this candadian company? i still owe a bunch on this car so i dont want to just dump it if it can be fixed. just to make sure i understand i do need a new motor that matches with my vin and need to get the head studs as a kit? or is it one or the other? im born and raised on Oahu in Kaneohe

[2002 Caddy]

thx for the help i have a guy who worked for caddy who quoted me 16hrs or so for the labor. do you know the website for this candadian company? i still owe a bunch on this car so i dont want to just dump it if it can be fixed. just to make sure i understand i do need a new motor that matches with my vin and need to get the head studs as a kit? or is it one or the other? im born and raised on Oahu in Kaneohe

Sure the guy that sells the studs can be found here:
http://www.northstarperformance.com/

One or the other question? That comes down to how much you are going to pay for a used engine. The cost of this project is not the parts or the used engine. The cost is the labor to re&re the engine. once the engine is out of the car (a 12-14 hour project) it only takes a couple of hours to install the studs. Of course to swap engines it also takes the 14 hours to get the engine in and out.

If you have access to a cheap northstar engine from a local wrecker, you can do the swap, but keep in mind that ALL NorhtStar engines prior to MY 2004 have head gasket issues, some WAY worse then others... and you really need to find an engine as close to the one that the car came with as possible. GM made several changes to the engine over the years and the blocks, sensors and electrical systems are not always compatible year to year. If you swap engines you could find yourself with leaking headgaskets in a couple of years again... If (when) mine goes (if Cadillac hasn't got there act together by then) I will fix mine with the "Canadian Stud" That fix seems to be a permanent solution to these problematic engines.

The Gaskets are some thing like $100 shipped from RockAuto and the Head studs (and tools to tap and "machine" the block) are about $600 shipped... This is a labor issue, if you can do this yourself you can save the car...

16 hours is a fair estimate of the time a mechanic will need to do this. If you can find one in Hawaii who will work for $50 an hour you are looking at roughly $1000 just for the labor (dealers of course will charge at least double that, most mainland Cadillac dealers charge door rates of $100-$120 per hour)

There are a lot of great guys with free advice on Caddy Info...
http://www.caddyinfo.com/


Good luck.

BTW I love Hawaii, you are one lucky guy to have been born and live in such a beautiful and special place. Been to Oahu once, The Big Island, Lana'i and Kauai. But we seem drawn back to Maui every year. Got a spot picked out in Napili where I hope to retire.

[tmasayukih]

well thanks again for responding so quick and i hope u do retire in maui its a great island full of great people.