Northstar Head Gasket

[BigRedCadillac]

I am considering buying a 1997 Cadillac SLS. The owner is willing to sell it fairly cheap because they know it needs a very expensive repair. The car has been losing coolant and I had it towed to a mechanic to evaluate. He did some testing and said the car gas a blown head gasket. The engine sounds strong and does not knock (yet). The questions, should I:

1. Have the heads rebuilt?

2. Have the entire engine rebuilt?

3. Buy a used engine?

4. Buy a remanufactured engine?

5. Buy a new long block from GM?

How difficult is it to remove and install the heads if I were to do it myself and then take them to be machined and rebuilt? Does anyone have an estimate of the cost of these various options, or is the car a dubious gift?

[Cadillac Jim]

Exactly what you should have done depends on what else is appropriate to service or overhaul in the engine. We have no information on this car except that it is a 1997 SLS. The way the car is equipped and how that matches your preferences, the car's mileage, service history, and condition of the interior, paint and body are all important. I will say that a head gasket failure probably means that the coolant went at least 5 years without being changed, in a period ending about a year or so ago, and that one or more had bolts has pulled out. This may or may not bode well for the service history of the rest of the car.

The head gasket repair alone is pretty involved, as you would expect from a DOHC V8. The fact that the head gaskets need replacing means that the head bolt threads on the block need to be replaced with inserts, and Timesert is the GM-authorized (and required) repair for Northstar head bolts when the head gaskets are repaired. There is nothing else that necessarily needs to be repaired when the head gaskets are replaced, but usually the engine is out when this is done so you should take advantage of the opportunity to do some preventive maintenance on this ten-year-old engine. I would recommend that you consider these items:

• Inspect and replace, if necessary, the metal heater hoses that go behind the engine.
• I would replace the water pump and the belt, the thermostat, the radiator hoses, the heater hoses, etc.
• I would check the radiator for flow and leaks and perform any repairs that seem necessary.
• The spark plugs and wires are not totally invulnerable to aging. Ten years would earn them an honorable retirement in my car, regardless of mileage.
• If there is a lot of seepage around the oil pan or the half-block below the main bearings, now is the time to replace the half-block O-ring or oil pan gasket.
• If there is anything else that needs replacing, like the oil pump, now is the time.

What I think you should do now is to get the maintenance history from the dealer using the VIN, as supplemented by whatever the owner can tell you, get the OBD II codes. and run a CarFAX check. I would also look under the car to see if there is a lot of oil leakage, and if the car is drivable at low to moderate speeds without overheating, I would test-drive it. In other words, look at it just like any used car. Take the cost, risk, and delay in driving the car for any repairs you deem necessary into account, along with the KBB sale price for individual-to-individual, when you agree on a price for the car.

There are people active on this board who have performed head gasket repairs on their Northstars in their garages, without removing the engine. There are those who have had the repair done recently by independent mechanics and by dealers who can share their experiences.

I had multiple problems and high mileage when my head gaskets went and decided on a Jasper remanufactured engine, which is an expensive alternative but I thought that it was best because I plan to drive the car at least four or five more years. Most others tend to go with engine repairs, exchange rebuilt engines, or used engines. A Northstar with 90,000 miles but with a good maintenance history can be a very good investment.

[BigRedCadillac]

Jim, Thanks for your quick response. The car has 150,000 miles on it and the current owner has only owned it for a year (20,000 miles). The current owner doesn't know the name of the person she purchased it from. I would classify the car as average (certainly not clean or exceptional) but the current owner is sloppy and it could be the car was in much better condition when she got it. Body and paint are good, interior is dirty but I assume an auto detail shop could make it look much better. Lots of loose interior trim. The current owner said she had a mechanic do a "car check" on it when she bought it and everything was fine? My daughter owns a 1996 SLS the same color and features and I have found it very reliable and a joy to drive. I have considered buying the 97 just to have spare parts around even if I dont repair it. I am assuming I could purchase the car for under $600.

Has your experience with the Jasper remanufactured engine been a good one, what was the cost for the engine? My mechanic was in favor of installing a used engine and said installation labor would cost about $1000. Does that seem reasonable? Thanks again

[Ranger]

I think Chazglenn3 had a Jasper engine installed if I remember correctly not too long ago. He will have some info on that for you.

[Cadillac Jim]

Remove and replace a Northstar is typicaly about $1500. I have heard of people getting very good jobs done for $1000. A used engine will run you what it will run you, but you can figure $1000 to $2000 or somewhere in between, depending on where it comes from, how many miles it has on it, etc. Be very careful about the year because little things like the alternator mount change from year to year. Others are more knowledgeable than I about what years Northstar fit in a 1997 SLS. I would venture that only 1996 and 1997 will fit with absolutely no problems, but I would think that 1995 would be a good bet, too.

A really good rebuilt engine will run you about $3500. If I were going to pay any premium at all over a used engine I wouldn't lowball a good rebuild. You can tell these because they rebuild your engine, or they don't have same-day shipment. Some of these are very good, based on some posts I have seen here. I have a Jasper remanufactured engine, which in addition to a complete rebuild has precision align-bored main bearings and full attention paid to all GM specifications for the Northstar. I have only about 7,000 miles on it but it is as good or better than the original. For example, there is a trace of crankshaft rate vibration at red-line in nearly all engines that I noticed in my original engine, but not in my Jasper re-manufactured engine, so primary engine balance is better. That means that the engine will be less prone to develop oil leaks over time.

Other things you need to look at in an older car is its history. This car has electronic control of ride, handling, brakes, stability, transmission, engine emissions and air/gas mixture, and the height of the rear end. Some components are very expensive, such as the struts and rear air shocks. If this car has spent a lot of time swimming in salt in Canadian winters, some of these components will suffer. That's why I suggest that you get a title and major event history from CarFAX. It can predict your cost of ownership.

Using this car as a parts car for a 1996 seems like a waste of a perfectly good car. Unless this $600 SLS turns out to be a salt-eaten money pit, I would clean up the interior and fix it, and drive it proudly like I own it.

I think Chazglenn3 had a Jasper engine installed if I remember correctly not too long ago. He will have some info on that for you.

I haven't see Chazglenn3's posts, but I hope that he is as happy with his Jasper as I am. I have nothing but good to say about mine.

[Ranger]

I think he was happy with Jasper.

[BigCat83]

I'm in the middle of Timeserting my '97 Eldo now (91,471 miles). If the car is in good shape otherwise; put a Jasper motor in it. You can Timesert it; but is a motor with 150K on it really worth Timeserting - IMO - NO.

[Cadillac Jim]

I'm in the middle of Timeserting my '97 Eldo now (91,471 miles). If the car is in good shape otherwise; put a Jasper motor in it. You can Timesert it; but is a motor with 150K on it really worth Timeserting - IMO - NO.

This may be where we are going once you read the codes, get the service history, look under the car, and have a test drive. The half-case O-ring is known to become really leaky anywhere from 120,000 miles up, etc. I think it is likely between a used engine, a rebuild, or a remanufactured engine, if you think that the interior is OK with a clean-up and tighten-up, and the rest of the car is solid. When you get the codes, we will be particularly interested in looking for transmission codes, suspension codes, air conditioner codes, and body codes. Which ending we end up recommending depends on how the rest of the car shakes out.

When you test drive it, make sure that the air conditioning works OK, blower motor first, and that it blows out the vents that the console lights say it is blowing out. Try the windshield de-fogger and rear window de-fogger buttons, too. Make sure that the Check Engine lights with the key on, engine off, and that all the other lights come on right after you start the car and they all go off after a few seconds. Take the car up to at least 45 mph and let it cruise at a steady speed, and make sure that none of the warning lights comes on. If everything shakes out OK and you put a Jasper in it, you will likely end up replacing the 1996 with this car and using the old one for parts.

If you get a Jasper or rebuild from your core engine, you won't have to worry about matching the year like you will with a used engine. Jasper works from your VIN and gives you an exact match. Mine was waiting at the mechanic the day after we ordered it, and it was a few more days before our appointment came around. I bought the installation kit from Jasper, which included all the necessary gaskets and hoses, thermostat, spark plugs and wires, thermostat, water pump and belt, etc. etc. etc. and I added the heater and bypass hoses. My installer replaced the metal heater hoses and cleaned out the EGR. The engine was installed in two days and ready after a test-drive the next morning. It hasn't been back since.

You can avoid lots of problems by getting a good installer, no matter which option you choose. If you get a Jasper remanufactured engine, look for a Jasper literature or signs, or a Jasper sticker on the windows of the shop that installs it so you can be sure that this installer knows Jasper. Note that no one has discussed rebuilding your heads (Northstars usually don't need it pretty much regardless of mileage) or a long block from GM, which is just a little more expensive than a Jasper engine. Jasper and some others have an unconditional 36-month warranty that includes the labor of replacing the engine under warranty; I'm not sure that GM can match that.

[GreenMachine]

I have a quick quesiton for you guys, Jim your first post in this topic got me thinking, can any GM dealer look up service history of a vehicle or does each dealer keeps it owns records for just the cars the service (in other words are the dealers "networked" so that if the car had a repair done at Keyser Cadillac, Braun Cadillac-SAAB can see that piece of the record.) Also if they can, were they able back in 98?

Just curious is all

[Cadillac Jim]

(clip) can any GM dealer look up service history of a vehicle (clip)

I believe that there is a central dealer database by VIN that is pulled for any car that comes in under a signed work order, even for an oil change. Someone with recent GM dealer experience can verify this (or not). Apparently CarFAX and others that do history searches by VIN access this database from GM and others. Jasper has my VIN on record, and the next time I take my car to a dealer for, say, the A/C compressor clutch, the engine swap and new engine number will come up in this database. Jasper has my VIN and my installer has a Jasper customer number, so this may already be in the database.

[KHE]

I'm in the middle of Timeserting my '97 Eldo now (91,471 miles). If the car is in good shape otherwise; put a Jasper motor in it. You can Timesert it; but is a motor with 150K on it really worth Timeserting - IMO - NO.

The Northstar will go several hunderd thousand miles before it is worn to the point of making a fix/replace decision. 150,000 it is hardly broken in. There will not be any ridge at the top of the cylinders and the factory hone pattern will still be visible on the cylinder walls. If he does the work himself, the parts run about $800. If the case half seal, oil pan gasket and rear main seal are replaced, it is about $150 more for the parts. If the case half or oil pan area are leaking, the time to fix the leaks is when the engine is out.

The question that he needs to think about in making is will the car be worth more when it is repaired than the market value?

[Regis]

I have only about 7,000 miles on it but it is as good or better than the original. For example, there is a trace of crankshaft rate vibration at red-line in nearly all engines that I noticed in my original engine, but not in my Jasper re-manufactured engine, so primary engine balance is better. That means that the engine will be less prone to develop oil leaks over time.

I don't mean to be curt Jim, but isn't it a little early in the game to be putting your Jasper engine on a pedestal? I know Jasper makes a great engine but I don't think you should give them so much credit until you have at least 100K on the clock. A lot of things can happen along the way. And I hope you're still as positive if and when your Jasper makes it to the first 100K benchmark. In regards to the "trace of crankshaft rate vibration at red-line"..... is that a documented problem with the Northstar or is that just your opinion? Because I red-line often and I don't get that subtle vibration. Perhaps more red-lining should be in order?

BigRedCadillac,

There is really no reason why your 150K mile Northstar shouldn't be timeserted with a new head gasket installed. If the Northstar engine has a weak point the head gasket would be it. But that's true with most aluminum block engines. I'm pretty much just reciting what was preached to a lot of us by someone referred to as the Guru and who was hands on in the developement of the Northstar. If it helps in your decision making, my 94 Northstar has 225K miles on it and still has the original head gasket and runs like a champ. I'll save the bragging for when I hit 300K. I can't say enough about performing Regular maintenance.

[zonie77]

How does it run now? If it runs well with the exception of overheating and possibly rough running when cold I would recommend repairing the current engine. You know what you have. If it does run well I would not have the heads redone, it would be a waste of money. Most people who did the HG's did not have the heads done.

Only 96-99 (someone can correct me if I'm wrong) will replace yours.What are the chances of finding a good used one? I know every used engine someone asks about has 60K but how many cars that old really have 60K. Engines have been replaced only to have the used engine worse than the original. So that leaves a Jasper or some other rebuilt. A Jasper is $3500. KHE's estimate of $800 to replace HG is accurate. I agree with everything he and Regis wrote, BTW, a N* should go at least 250K. It makes more sense to repair the original engine. The value of the car doesn't really justify putting $4K into it.

[KHE]

I agree with Zonie77 - don't waste money on "re-doing the heads" unless you have a burned valve or broken valve spring, it is a waste of money.

[Cadillac Jim]

BigRedCadillac -- Please allow me to summarize the vast and seemingly contradictory advice you see here. In actuality there are no contradictions at all.

ADVICE

Get the whole story on the car and the engine and make an informed decision. Get the OBD II codes, look under the car and get the maintenance history, and run a CarFAX title check. If the car is good to go, then you can decide what to do.

150,000 miles won't wear out a Northstar. If it isn't leaking a lot of oil, a TimeSert job (head gasket repair with inserts for the head bolt threads and new had bolts) is all it needs. The heads shouldn't need rebuilding.

If you are looking at other engine repairs besides the head gasket repair, you may be able to get everything done cheaper if you do it all while the engine is out.

A quicker and simpler way is to exchange the engine with a used, rebuilt, or remanufactured engine. These alternatives, with pros and cons, include:

• A used engine. Be sure that it is a VIN "Y" engine compatible with your model and year. Pros -- least expensive; Cons -- availability for your make and model are what is out there when you look, you don't know where its mouth has been.
• A rebuilt engine. Pros -- less expensive than remanufactured. Cons -- some risk; research the warranty.
• A remanufactured engine from a reputable outfit like Jasper. Pros -- lowest risk for the long term; Cons -- most expensive.

With a rebuilt or remanufactured engine, you should get a written three-year unconditional warranty that includes labor to remove the bad engine and install the replacement engine.

VIEWPOINTS

Some look at the car like it is merchandise available for sale or trade at any time. This viewpoint looks at the cash or trade value of the car versus what you pay for it and any repairs at the time it is ready to drive. Others look at the value of the car at the time you buy it and the return on investment of repairs over the period of time that you drive the car. Some would value a car with a quality refreshed engine higher than KBB prices; this is a difficult argument for others because such cars are quite rare on the market and KBB gives no credit for a "new" engine. Others simply want to minimize the cost per year or per mile. Some will feel quite strongly about their viewpoints, but, it's your car, and your call.

RISKS

The background of this car is hazy past the current owner, and the $600 price is disconcertingly low. This is why a CarFAX check is important, and why you should look at things like the transmission and suspension for deferred maintenance or current codes.

[Ranger]

I have a quick quesiton for you guys, Jim your first post in this topic got me thinking, can any GM dealer look up service history of a vehicle or does each dealer keeps it owns records for just the cars the service (in other words are the dealers "networked" so that if the car had a repair done at Keyser Cadillac, Braun Cadillac-SAAB can see that piece of the record.) Also if they can, were they able back in 98?

Just curious is all

They are networked. Any GM dealer can pull the service history on any GM vehicle. It is probably not need to be said, but that would only show work performed by a GM dealer and not an independent shop.

[joeb]

i would think a 97 sls with 130k miles would go for around 4-5k which is probably what the current owner might have payed in the last year. if the mechanic she goes too says a used or rebuilt motor will cost 3k or so installed and she decides to sell it as is instead, than 600 is not out of line.

[BigRedCadillac]

I agree with Zonie77 - don't waste money on "re-doing the heads" unless you have a burned valve or broken valve spring, it is a waste of money.

Well i jumped into the pool this afternoon and bought the car. I still dont have a clear picture as to how I am going to proceed. I checked on used engines (not rebuilt or remanufactured ) and I was told that although the engine would be warrantied (for 30 to 60 days) there was no labor warranty for installation. While I am not suprised this makes that route unappealing unless you have a definitive history of the engine in question.

I called two Cadillac dealers about just doing the heads, one told me that as a matter of policy they would not redo heads on a Northstar engine with 150,000 miles on it the other told me that I should plan on 20 to 30 hours of labor @$90.

I did some research on ebay and google and found two or three possible sources of engines though I never could find a web site that sold "Jasper" engines.

The one ebay listing that caught my eye was $2695 plus $99 shipping:

"Custom Innovations has been specializing in Cadillac Northstar engines for many years......The #1 most common cause of failure on these engines are head gaskets, due to 'pulled' head bolt threads. We perform a process to replace the threads, which is recommended by Cadillac. It is called 'Timeserting,' which consists of drilling the old threads, tapping the new hole, and installing a solid alloy insert. This insert is significantly stronger than the factory threads. We are proud to say we have not had a single failure with this procedure! "

If I paid $3000 for an engine and it cost me between $1000 and $1500 to install it I would have about book value in the car but I would hopefully know the engine in it had a lot of life left

My other alternative would be to try and go the least expensive route and just fix the heads either on my own or through a less expensive mechanic than the Cadillac dealer route.

The big question i have for this group, how practical is it to R & R the heads without pulling the engine?

[JimD]

....

The big question i have for this group, how practical is it to R & R the heads without pulling the engine?

It can be done and has been done. The consensus seems to be that dropping the cradle makes a head gasket job easier and faster.

[Cadillac Jim]

I would NOT use the dealer for R&R the motor because they charge top dollar but are a slave to the available technicians for the job. You might get a good job done for $1800 - $2700 but you can get a good job done for $1500, too.

The Jasper web site is http://www.jasperengines.com/. I would deal with them directly until it is time to buy the engine, including having them recommend tow or three installers in your area, then work with the installer of your choice in who orders the engine.

You seem to be inclined to look at the DIY angle, and that is certainly the most economical route. Lots of people here have done it; one of them has already chimed in. If you do it yourself, you can look at the O-ring and oil pan gasket and add them to your agenda as you deem appropriate. The only other major issue with old Northstars is stuck rings, and that can be handled with the engine in the car. When you are done, you will have the satisfaction of handling the problems yourself as well as minimize your expenses, and you will know that all the bolts and nuts are in the right place with the right torque.

This could be the beginning of a long and satisfying relationship with your SLS. Good luck, and Happy New Year.

[zonie77]

Doing HG's on an N* is a long tedious process but it is not technically difficult.

I would NOT recommend doing it in the car. It has been done but it is the hardest way to do it. The rear head and the timing chains are very difficult to access in the car.

The engine was designed to be dropped out the bottom. The cradle serves as the engine stand. You do not have to seperate the engine/trans. Pulling it out the top is harder than dropping the cradle.

My recommendation...drop the cradle, timesert the block and reuse the heads as they are.

I wrote up the first one I did on the "other" board:

http://www.cadillacforums.com/forums/north...d+gasket+repair

[BigCat83]

I agree with Zonie77 if you are determined to fix the engine yourself.

Get a copy of the FSM, use the description for dropping the cradle as a checklist to disconnect and remove everything that must be removed and drop the cradle.

I'm in the middle of the same project now on my '97 Eldorado and and have been posting an almost daily journal of my progress, which you should review.

Good luck. And feel free to ask about my experiences.

[Cadillac Jim]

The page for Helm, Inc manuals for the 1997 SLS is here. The home page for Helm, Inc. is here. One parts source recommended by many is Rock Auto. Used parts for Cadillacs are available from Cad Auto.

Keep us posted by keeping this thread alive with posts of your progress, questions, and questions. Good luck and Happy New Year.

[BigRedCadillac]

The page for Helm, Inc manuals for the 1997 SLS is here. The home page for Helm, Inc. is here. One parts source recommended by many is Rock Auto. Used parts for Cadillacs are available from Cad Auto.

Keep us posted by keeping this thread alive with posts of your progress, questions, and questions. Good luck and Happy New Year.

Jim, I already have a complete manual set for the 98 Seville, do you think there is much difference between the 98 and the 97. My manual set says "Preliminary" on the cover, i wondered if that didnt mean much of the info was from the 97 model year anyway? I was also curious, while checking out one of the previous posters information on head gasket repair I popped open a sidebar ad for a product called "Steel Sealer" or something like that. I have never had much luck with leak stop type products but If there was a magic elixcer which would fix this problem it sure would be a lot less painful.

[Cadillac Jim]

There was a platform change in 1998 for the Seville. The engine is pretty much the same for the 1997. There may be some differences in the way the engine cradle drops, the accessory mounting on the engine, etc. Others with experience with the 1998 and later Seville platform and FSM will likely chime in. I would go ahead and get the 1997 FSM and use it for your 1996 and 1997 Sevilles, which are almost identical.

I wouldn't even consider an attempt at a chemical repair on a Northstar because the head gaskets practially never give problems unless a head bolt pulls out, hence the TimeSert repair, which no chemical treatment is going to address.