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Need Northstar advice


stokes

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I am thinking about buying a 2001 DeVille with 40k miles.I am concerned about the Northstar engine and the problems I've heard about with the head gasket.I tried a search and didnt come up with much,so I appologize if this subject has been beaten to death.If someone could,I'd appreciate it,give me some insight to exactly what this problem entails.Is it something that is kind of like a sure thing to happen?Is there a certain mileage I should expect it?Is there a way to prevent or lessen the likelihood of it happening?I have heard the term "Timesert" (I think thats what it is) used in association with this "problem",what exactly is that and is it something I could do myself?I am fairly well mechanically inclined,I have,with the help of this board,a service manual and the on board diagnostics on my '92 ( I know this feature is not on the 2001 I'm looking at) do most repairs on my Seville myself for the last 100k miles I was able to put on this car.If it does need to be done by a shop,is it a very expensive deal?A lot of questions,I know,so I really appreciate any help and insight you guys can give me.Any other known problems associated with this model would be a big help as well.Thanks in adance for your assistance.

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I am not an authority on any of this, but here is my 2 cents worth. My car went 220,000 miles before it failed. That seems like a reasonable amount of miles for any engine to last. I am using the northstar performance studs instead of the timeserts. Just for a simplification, the timeserts are similar to a helicoil, though a helicoil is unacceptable for this repair. My car is a 99 and I hear it is the most failure prone year.

Before I would buy any pre 2004 northstar car I would get the kit from autozone etc.. to check for combustion byproducts in the coolant! As far as you repairing one, that is quite subjective. I am not a mechanic, just a guy that has done his own work for years, and I am doing mine. I also am in no hurry, have other vehicles to drive. You need a way to get the body up in the air far enough to get the engine out the bottom. I definitely wasn't looking forward to this job, and still don't care for it, but it's getting done. Most times the job is considered more expensive than the value of the car if you have to hire it done, if a dealer does it. There are people advertising on ebay and craigs list for reasonable rates if you live near enough not to have to ship it. I couldn't vouch for any of them. I love my car, but can't say I would do this again. I would much prefer one already done, but then I would have to KNOW the mechanic before I would buy it.

Other opinions will surely come. 40,000 miles seems like you should get a lot of use out of it, but I would absolutely test the coolant. good luck to you, and I hope you like it as much as I like mine.

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Thanks for that,Mike.I can do a lot of mechanical stuff,but dropping an engine isnt in on my list.So what exactly is the problem,is it that the head bolts strip somehow?I take it that GM remedied the issue in '04.Are there any preventive measures?

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I am not willing to state a cause for the failures. I took all the bolts out of my engine and not one had aluminum on the threads. That tells me the gasket failed, not the bolts or the block. The coolant definitely needs changed, there is a chemical reaction that occurs when it is left too long. There seems to be different opinions as to the cause of the failures. I am not willing to take the chance that the bolts or holes are reusable, therefore the studs. I also intend to drive mine another 200,000 miles. :glare: The ls engines don't seem to have the problem, so that really should rule out dex cool being the culprit, unless they use a different type of head gasket. In any case the cause has been debated with no consensus, that I know of. Simply keep the coolant changed and enjoy the car. As for the 04 change, yes they are different, and NEWER so maybe they are better or maybe they haven't reached the age of failure.

Sorry if I really didn't answer your questions, I can't. I sure like my northstars though.

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First off, a HG failure is not a given. It may or may not happen and there is no "average" mileage at which it might. The only thing you can do is frequent coolant changes (every 2 years. No more than 3). As Airmike said, doing the job is a major undertaking. Having it done is pretty expensive.

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So,is it the head gasket that fails or the head bolts themselves?Is it advisable to check/torque the bolts periodically?If it is the gasket itself,what is the reason for changing the bolts?What exactly is the kit from autozone etc.. to check for combustion byproducts in the coolant! that you mentioned?Thanks for the responses so far,guys,I am really on the fence about this car right now.I have had my '92 Seville for about 9 mostly trouble free years and am quite concerned about the northstar issue.

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I would say no on the bolts. I wouldnt think disturbing them would be a good idea. the only way is if you suspect that threads have pulled

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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You can get the test kit from oreilly, autozone, etc.. probably called a block test kit. It is part of the tool rental/loan program that will not cost anything for the tool. You will have to buy the fluid that you put in it. It mixes with the coolant and if exhaust is present the fluid changes color, indicating a blown head gasket.

If the car test comes out ok I would not hesitate to buy the car if it is the car you like. You need to remember that people almost never get on these forums looking for other people commenting on how great their cars have been. They mostly come looking for help AFTER a problem occurs. If you could get your head gasket repaired for $600 people would just take the car to a local mechanic and have it done, and never be on a forum etc.. looking for answers. When the expense gets so high then people start looking and talking, therefore the reputation develops.

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Thanks Airmike,great replies.I do really like this car.I've had my '92 for about 9 yrs and love it.Got it with 37k miles,has 137k now.It needs some work,one of the issues is computer related,just ordered a new one,if that solves the issue I'll do the brakes and front struts and give it to my son,hopefully he'll get another 100 out of it.This car I'm looking at is at a local used car lot who I do trust,one owner,40k miles and very clean 2001 DeVille.He's also got a 2000 Grand Marqi that he'll give me for the same price,36k miles.He says either car is solid but he recommends the Mercury only because of the head gasket issues the northstar is known for.My big concern is that even tho I love the Caddy,am I going to drive the car for 10 years worrying for that shoe to drop.Is it really that common a problem?I've read about it a lot on this forum years ago but never gave it much thought since my car had the 4.9,not the northstar.I've bought 3 cars from this dealer over the years,including my Seville and every car was "the best used car" I ever owned.I sent at least a half dozen people to him and everyone of them was happy with him,so I figure I should listen to him,but I really like the Caddy and figured I'd come here and get some practical advice from people with firsthand experience.Your experience is certainly excellent,any car that goes 200k+,a blown head gasket is not unusual or unreasonable.One more question,if you dont mind,he was asking $8,999. for the car,he's willing to give it to me for 7 grand flat,again its a '01 DeVille with 40k mls very clean,fully serviced and he put new CV joints in it.I think thats a pretty good deal,what do you think?

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This is what car buying comes down to for me. Am I going to like the car, continue liking the car, or wish I had bought better, faster, more gizmo's etc.. If I paid $1000 more than the next guy, is it going to make me feel bad. With a few exceptions dealers put there cars for sale at a price that is comparable to the next guy. The options, miles, etc will raise and lower the price, but Joe and Bob are going to be real close to the same price, if optioned similar. The cars I have are in my price range and if I gave more or less than the next guy is really immaterial. As long as I look at it and am happy every time I get in it "I'm happy" If your dealer has a good rep, I imagine the car is not a steal, he wants to make a living, and its not overpriced or he would not have a good rep and repeat business. I, like anyone, like to think I got a bargain, but that isn't the biggest desire, nor a deal breaker.

I really couldn't say about your particular car. I am not willing to do KBB or ebay comparing. Your dealer has probably set it right in the middle somewhere. No doubt $2000 off sounds like a deal, but I am not in NYC either. Sorry if I didn't answer your question. Just make yourself happy every day, not just on buying day.

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I normally dont "look back" after buying anything,car or otherwise.If the price is what I am willing to pay at that moment,I dont look later to see who got it for less,or even think about it.Was just curious as to what you thought about the price.I think it is good and will not give it a second thought if I decide to buy it.I kind of wish I never heard of the head gasket issue.I get the feeling that if I buy it the issue will always be in the back of my mind.Thanks for the tip on that test kit.I checked autozone,I'll test it and see to make sure the car wasnt sold because the problem is already starting,or ask the dealer if he can have it done.Since he already alerted me to the potential problem and other reasons I feel I can trust him.

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....You will have to buy the fluid that you put in it. It mixes with the coolant....

Not quite. The air above the level of the coolant is what is being sampled.

The instructions included with the AutoZone tester are very detailed.

AutoZone tester = 27145

Autozone test fluid = 25739

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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So,is it the head gasket that fails or the head bolts themselves?

That's the chicken or the egg question. Two different theories on that. Neither has eve been proven.

Is it advisable to check/torque the bolts periodically?

NO! The bolts come from the factory with a thread sealant/locker on them. You DO NOT want to mess wit them unless you are removing them.

If it is the gasket itself,what is the reason for changing the bolts?

"Most of the time" threads come out with the bolts. Even if they don't, installing installing inserts or studs is a precausion. Many times the threads will pull when retorquing the bolts or even years later. You do not wan to do this job twice.

What exactly is the kit from autozone etc.. to check for combustion byproducts in the coolant! that you mentioned?

Yes.

You can get the test kit from oreilly, autozone, etc.. probably called a block test kit. It is part of the tool rental/loan program that will not cost anything for the tool. You will have to buy the fluid that you put in it. It mixes with the coolant and if exhaust is present the fluid changes color, indicating a blown head gasket.

The test fluid NEVER mixes with the coolant. Air from the surge tank is bubbled up through the test fluid. If the air contains exhaust gases the fluid turns yellow. If coolant mixes with the test fluid it is contaminated and the test tube has to be cleaned and the procedure started over.

:EDIT

Oops, Jim beat me to it.

Is it really that common a problem?I've read about it a lot on this forum years ago

Not saying it is not a problem, but keep in mind that people come to these forums when they have a problem. You never hear from those who don't. Gotta keep things in perspective.

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Good info there,Jim,Ranger.So the real issue is not the gasket itself and the bolts become the problem when you change the gasket.That makes things clearer.I was wondering what keeping up on the coolant had to do with the bolts.So if I test the cooling system for exhaust by products and come up okay at this mileage I will know the leak hasnt started and can be reasonably sure the gasket should last like any other car.The real problem comes when the gasket does goes because of a flaw in the bolt/thread insert when you do have to remove them.If the gasket doesnt go the bolts wont become a problem.Does this reasoning make sense to you guys?Again I apologize if this has been covered,but my search didnt come up with anything as specific as I think I am asking.A lot of the discussions seem to start beyond my basic knowledge of the issue.

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Neither the gaskets nor the bolts are a problem... until the gasket starts leaking combustion gases into the coolant.

Then you replace the gaskets, install TIEMSERTS and new bolts or install studs.

Problem is then solved.. probably forever.

And then again, it may never leak... but that's something you just can't tell ahead of time.

For what it's worth, it seems like a lot of them that do start leaking, start at around 100,000 miles or so.

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Enough is enough. Please lose the language and mindset of inserts or helicoils or studs or other unproven "fixes". Nothing need be done until there is evidence of head gasket failure. And headgasket failure is not unique to Northstar engines.

GM/Cadillac and other car makers have been clamping aluminum heads to aluminum blocks using ferrous bolts for decades; they know how to do that. The physical/chemical challenge is how to avoid the predictable oxidation/corrosive action at the point where a ferrous bolt thread contacts an aluminum block thread. GM dealt with that in the Northstar by coating the head bolt threads AND designing the head gasket to keep the bolt hole in the dry.

A head gasket can fail in such a way as to simply push combustion byproducts into the cooling system.

Worst case is a head gasket fails in such a way as to allow coolant to come in contact with the head bolt threads. The coolant acts as an electrolyte and promotes/accelerates the predicatable oxidation.

Reports of head bolt thread failures soon follow. But the reality is, the gasket failed.

It would be folly to open the top end of a Northstar for any reason without properly dealing with the head bolt holes/threads in the block. GM/Cadillac Service Manuals specify TIMESERT products (http://www.timesert.com/) be used when clamping the engine back together.

Anyone not prepared to assume the risk of a pricey repair with any vehicle at any time should buy new and trade when the bumper to bumper warranty expires.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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For what it's worth, the Grand Marquis and Lincoln Town Cars are not immune from headhasket failures either. Also, I see some of them burning oil - visible blue smoke while accelerating. I looked at buying a 2003 Lincoln Town Car a couple of years ago that supposedly had bad headgaskets. I figured it was the intake manifold gasket and my plan was to buy it cheaply, repair it and sell it to make some money. I started doing some research and the Ford 4.6 engine has had cases of headgasket failures.

I spoke with the local Lincoln dealer inquiring about replacing the headgaskets. I figured since it was a RWD car, the headgaskets could be done with the engine in the car with plenty of room compared to a FWD car. Wrong - the dealer said the engine had to come out. In the meantime, the owner of the car had it repaired and his selling price was then at full retail value so I passed.

I doubt a Northstar with 40,000 miles on it would have a headgasket issue but it would be a good idea to test it prior to purchasing it. The first thing I do after purchasing a "new" used car is to change the oil and coolant to establish a baseline.

The issue with headgaskets has not deterred me from owning a Northstar. I have had three of them now. My first one: a 1996 Seville that was 4 years old and had 54,000 miles on it. I sold it a year and a half ago with 150,000 miles on it. Never any issue with the headgaskets. In fact, when I bought it, I knew nothing about Northstars until I found this site. The second one: a 1997 Seville STS that I bought knowing it had bad headgaskets. It was a North Carolina car and had 105,000 miles on it at 9 years old. I repaired the headgaskets and 6 years later it now has 172,000 miles on it. Again, I repaired it properly and don't expect to have an issue with the headgaskets. My third one: a 2005 Deville I purchased in 2009 with 39,000 miles on it. No issues with the headgaskets.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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NEXT Question. Why in the world would he put new CV joints in this car at 40,000 miles?

Never underestimate the amount of a persons greed.

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NEXT Question. Why in the world would he put new CV joints in this car at 40,000 miles?

Was actually wondering that myself.Apparently I wasnt paying attention too well,he said he changed the boots.

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KHE,I realize no vehicle is "immune" to haedgasket,or any failure for that matter.The first time I heard anything about the Northstar issue was here as well.I didnt fully understand what was going on because it didnt matter to me at the time and I didnt look too far into it.I had the misconception that the bolts were the problem,but I now see that the bolts become a problem only after the gasket fails and they have to be removed.I assume with other cars,if the headgasket fails,you can change them and put the same bolts back in.As I think I understand it with the northstar,when you remove the bolts the threaded inserts come out with them,or something to that effect.Do I have that right?If so,I guess my concern is if the northstar is really more prone to a headgasket failure than other vehicles.I get the idea that some people think,and it makes sense to me,that if you keep up on the coolant maintenance,it will help keep the gasket from deteriorating.Thanks for your input.Its actually good to hear from the other side,cars that actually go the distance without a failure.

JimD,I have been driving used cars for close to 40 years and I am well aware of the pitfalls,but I wouldnt want to pay a premium price for a used car that has what seems to be a likely problem that will cost 3 to 4 grand to fix.If it were a $500 to $1000 fix,I wouldnt even be asking.Sorry if the subject annoys you,but if "enough is enough" as you say,just change the channel.

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Neither the gaskets nor the bolts are a problem... until the gasket starts leaking combustion gases into the coolant.

Then you replace the gaskets, install HeloCoils and new bolts or install studs.

Problem is then solved.. probably forever.

And then again, it may never leak... but that's something you just can't tell ahead of time.

For what it's worth, it seems like a lot of them that do start leaking, start at around 100,000 miles or so.

Helicoils are a gauranteed failure. A repair must be done with inserts (Timesert or Norm's NS300L or studs).

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Neither the gaskets nor the bolts are a problem... until the gasket starts leaking combustion gases into the coolant.

Then you replace the gaskets, install HeloCoils and new bolts or install studs.

Problem is then solved.. probably forever.

And then again, it may never leak... but that's something you just can't tell ahead of time.

For what it's worth, it seems like a lot of them that do start leaking, start at around 100,000 miles or so.

Helicoils are a gauranteed failure. A repair must be done with inserts (Timesert or Norm's NS300L or studs).

I am so sorry I said that...I apologize to everyone.

I meant to say TimeSerts and to also say to "NOT EVER" use helicoils...

I need to proofread my posts better.

I will go back and change it.

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"Was actually wondering that myself.Apparently I wasnt paying attention too well,he said he changed the boots."

Hmmm, quote function not working again.

I still wonder HOW and WHY he changed the boots. If he took out the CV joints and half shafts to change the boots properly, did he relubricate everything before reassembly? I don't understand why someone would go through all that trouble just to change the boots unless they were torn or damaged. Now if they were torn or damaged, additional steps would need to be done to ensure that the shafts and CV joints were not harmed by water intrusion.

If he used "split boots" which are the common aftermarket replacement, he may have done more harm than good.

Never underestimate the amount of a persons greed.

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I am sure he had them changed because they needed to be.He fully services every vehicle he sells,well not himself,he has a mechanic that does it.If it needs brakes it gets brakes,if it needs a hose.....etc.I am really not concerned about that,like I said,I've bought 3 cars from him over the years,never had a problem.My only concern here is if the Northstar is actually more prone to head gasket failure or if it is just a case of the fix being so expensive that it has become exagerated.

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I am sure he had them changed because they needed to be.He fully services every vehicle he sells,well not himself,he has a mechanic that does it.If it needs brakes it gets brakes,if it needs a hose.....etc.I am really not concerned about that,like I said,I've bought 3 cars from him over the years,never had a problem.My only concern here is if the Northstar is actually more prone to head gasket failure or if it is just a case of the fix being so expensive that it has become exaggerated.

In my opinion that is the most likely case,

On the majority of cars, the head gasket can be replaced without dropping the engine.

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