Engine Replacement

[tommysls]

I am considering an engine replacement on my 98 sls instead of having both head gaskets repaired.

Any happy ending stories out there about N* replacements???

Thanks

[maydog]

I had my N* replaced for approx <$1900, I was quite the headache, as the mechanic I chose had some pretty inept help. Runs great now at least.

That thread is called "car needs work, tough choices"

[IaBoy]

Hey Tommy.. you should buy my 98 SLS that I hit a deer with. Perfect engine, great tranny.. and the whole car can be purchased for $2K. and you have enough parts to keep yours going forever!!..

Check out pics in the "For Sale" section.

Steve

[sesenter]

I have a 97 deville possible head gaskets. what makes you think its the head gaskets?

[sesenter]

JUST CAME FROM HEADGASKET SEARCH.. WHY SO MANY ISSUES.

IS THERE A COMMON PROBLEM.

[Ranger]

JUST CAME FROM HEADGASKET SEARCH.. WHY SO MANY ISSUES.

IS THERE A COMMON PROBLEM.

It seems to be the Northstar's weak point, especially if the cooling system has been neglected.

[Poobah]

Much of the engine replacement option depends on what you're thinking of replacing it with.

Used Engine - Cheapest but also the riskiest option. There is absolutely no assurance you won't be back in the same situation before you know it.

Rebuilt Engine - A lot depends on who did the rebuild, how good a job they do, and what guarantee they offer. (I would certainly shop quality and guarantee, here, and not just go for the cheapest price.)

New Engine - Probably the most expensive approach, but you do get a brand new engine with a factory guarantee.

I went through this about a year and a half ago. I was suprized to find that the labor to replace the engine is only slightly less than the labor to replace the head gaskets. Why? Either way, the powertrain sub-frame, or "cradle", which holds the engine, transaxle, and running gear has to be lowered out of the car. Once the cradle has been dropped, the additional work to R&R the heads is not much more than to R&R the engine.

You never know what you are going to find once you get the heads off but the general sense I get from this board is that the Northstar is a very robust engine that can give many years of service after a head gasket replacement.

I went the head gasket replacement route.

During the process, we discovered that the car has a 98 or later block in it. Why? It was a used car, what can I say? All the internal parts looked nearly new (cylinder walls had lots of scoring and no wear ridge at the top, valves and seats all looked good, cam lobes looked good, no visible cracks in the heads, head and deck surfaces were fairly true). We Timeserted all the head bolt holes and put it back together using all genuine OEM parts, and following the Factory Service Manual proceedures to the letter

I have put a little over 20,000 fairly aggressive miles on the car since then with absolutely no problems.

Of course, there are no guarantees and your experience may be quite different, but from what I read on this board, my experience is not at all uncommon.

Head gasket repairs are always expensive and nerve-wracking. There are many options to consider and decisions to make. However you choose to proceed, keep us posted. You'll find this board very helpful as you work your way through this. I know I did!

One additional thought: Try to get the work done at a shop where you can talk to the mechanic that is actually doing the work and see the engine as it comes apart and goes back together. You'll gain a much better appreciation of what a really cool piece of machinery the Northstar engine is!

Good luck!

[Poobah]

JUST CAME FROM HEADGASKET SEARCH.. WHY SO MANY ISSUES.

My head gaskets failed, not from cooling system neglect, but from fatigue cracks in the fire rings (the rolled stainless steel rings that edge the cylinder holes in the head gaskets).

Bbobynski said this was caused by too many thermo-cycles and that all-aluminum engines are very hard on head gaskets. GM is doing a lot of R&D to address this issue but, so far, gaskets made of advanced materials are not ready for production.

Aluminum-engined cars of all makes are prone to have head gasket problems. It seems like my mechanic always has at least one car in his shop with a bad head gasket, and they are of all makes, forign and domestic.

[Ranger]

One more time........ Give me a good ole cast iron engine anyday.

[Poobah]

One more time........ Give me a good ole cast iron engine anyday.

I hear Ya! Its all part of the trade-off that gives you a full-sized luxury car that gets 20 MPG.

I call it, "Economy at any cost."

[acklac7]

Head gaskets and time certs done about 2yrs/30,000 miles ago...I run her hard on a regular basis and no problems to speak of.

[sesenter]

OK THANKS FOR ALL THE HELP. NEXT QUESTION. DO I FIND A SHOP OR TAKE IT TO THE DEALER.

[Poobah]

OK THANKS FOR ALL THE HELP. NEXT QUESTION. DO I FIND A SHOP OR TAKE IT TO THE DEALER.

The dealer will be the second most expensive way to get the job done (the most expensive is someone who doesn't do it right and you have to do it over).

Book time to R&R the heads is 20 hours. This includes dropping the cradle but it does not include Timeserting or anything else you discover as the work progresses. Obviously, the name of the game is to find the most competent mechanic with the lowest hourly rate.

I always prefer to get work done in a small shop where I can see the work in progress and talk face to face with the mechanic that is actually doing the work rather than a big shop where I stand at the front desk and talk to a service writer. With a small shop, I feel more "connected" to the project and it's harder for them to give me a snow job. Small shops also tend to have lower hourly rates because they have lower overhead.

Two things I would absolutely insist on is that they use only genuine OEM parts and that they follow the proceedures in the Factory Service Manual to the letter. Do not let the mechanic try to tell you he has a better way to do something! My mechanic is quite competent but he had never taken a Northstar apart before. I loaned him my service manual and made sure he followed it step by step. Twenty thousand miles later the engine is running like a watch!

If the guy is a competent technician, if he follows the manual, and if he uses the right parts, the job should be successful.

Good luck!

[tommysls]

Thanks Poobah

Good information. My local caddie dealer quoted 32 to 36 hours @100 per and 800 for parts. When I asked the mechanic about timeserts he said "yeah we do that". Next day I requested a parts and labor list from them. They were glad to provide it - guess what - no timeserts mentioned on list.

I never trusted them much before and now I know I can't.

Have been having a hard time finding a shop who #1 knows much about northstars, and #2 wants to even do a northstar. Most I am finding have had difficulties in the past (probably didn't timesert),

others are qouting outlandish prices in 5 to 7000 range, dealer was 4000 plus.

By chance, I called an auto body shop who has done work for me over the years, very busy shop, always quality work. Asking them for a referral. They stated they have a tech that has much experience with this repair, so I'm going to visit them tommorrow with my list of questions (mostly from this site). Hopefully we can make some headway.

[jackc]

If you wind up considering a used replacement engine as a solution, be cautious about installing one that hasn't already had the head gaskets replaced using timeserts. You've already got one perfectly good Northstar with bad head gaskets. It would be a shame to wind up with two.

[sesenter]

just came back from the store AND check engine lite comes on , tell me random misfire. what is this and what does it mean?

[Ranger]

It means the PCM has detected a misfire. Did you have your fuel rail recently replaced under the recall? Many of us have had a misfire after that. Moving old wires around seems to take it's toll. A new set of OEM plug wires usually solves the problem. Did in my case.

[sesenter]

Thanks may be thats why its running like $$%* and its not a head gasket.

[rllovett]

Had my HGs done last year (94 Eldo/275hp/125k) for about $3600 at a place that's an independent, all-service (body/mechanicals/towing) shop. Was lucky enough to have someone who'd done a few before but they said "never again!" I found these guys by finding the local shop that grinds heads and asking them who worked on Cadillacs...I firmly believe that the devil you know is better than the devil you don't: fix what ya got. Mine's been fine except for the A-B trans solenoids which had been throwing codes during the era when I was engaging the limp home mode every other day. Am up to 140k and need about another 20k to get her down to the $.56/mile TripleA says it costs to keep a car on the road around here. Good luck!

[acklac7]

I believe my gasket and time sert job went about $3900 @ the local stealership.....Went through quite an ordeal in order to get the work done...At first all I heard was " NEW ENGINE, NEW ENGINE, NEW ENGINE!!!!.....THERE IS NO FIX IT NEEDS A NEW ENGINE!" It was only after finding this site that I was able to launch a suttle "attack" agianst the dealership...In the end the dealer fixed gaskets and threads under a A/M warranty. Warranty paid for most of the work...Out of pocket cost was about $1200.

[AliRaza]

I replaced my headgasket last year. Already put on about 15000 miles on it. No problems at all. I did it myself so took me few weekends, some nights and a lot of help from this forum. Only cost was gaskets, timesert kit, timserts and a few little things. Job was done under $800. But you need patience, and a lot of it. Dedication and just follow the processes.

It is running like new, running at about 27 miles/gal on the highway. Bright and shiny.

Again thanks to this board.

[Poobah]

I replaced my headgasket last year. Already put on about 15000 miles on it. No problems at all. I did it myself so took me few weekends, some nights and a lot of help from this forum. Only cost was gaskets, timesert kit, timserts and a few little things. Job was done under $800. But you need patience, and a lot of it. Dedication and just follow the processes.

You also need a Factory Service Manual.

[AliRaza]

Thats THE MOST IMPORTANT piece tha you need to do all of it.

Thanks

[tommysls]

Well the sls is in the shop and I feel comfortable with my decision to date. I got a reasonable hourly rate ($50) and a quoted of 20 hours. Much better than the stealership.

When I walked in the service manual was sitting on the front fender. Compression check on cylinders was ok. All plugs but #2 looked great. Signs of coolant on #2 plug. Still to early on job to find coolant leak yet - hopefully tommorrow. It seems exhaust getting in there somehow.

Engine replacement is still an option but it doesn't look like it will be necessary. I seem to have detected problems before they became to severe.

Thanks again everyone for all your info. I will keep you updated.

[tommysls]

AliRaza -

In previous posts when you were replacing your head gaskets you said you were going to post some photos and notes. Did you ever do this? I would find it useful.

Thanks.