LOOKS LIKE I NEED A LOTTERY TICKET!!

[gm_fan]

What are the chances of pulling my sts engine out , pulling off the heads, and just replacing the gaskets?? I torqued both heads back on with no pulled threads in the block. Like I said , I need to play the lottery tomorrow..Hard to explain to someone what a job this is to do and just keeping in mind it was a bunch of parts before it was assembled.I have done mechanic work professionally for 20 years now and I have never seen anything like it...gm_fan,,,,,,,

[Cadillac Jim]

This can easily happen - when an engine has been previously Timeserted. I would suppose that the Timeserts were installed properly but the head gaskets were not, if you had to replace the head gaskets on a Timeserted engine.

[BodybyFisher]

How many miles do you have on it since you replaced the head gasket?

You just completed this job?, as you were planning it in July 2010

What would cause you to just to torque down the bolts without studding or timeserting the block?

We had discussions with you regarding studding and timeserting in this thread

http://caddyinfo.ipb...=1entry171222

We have seen Northstars be "repaired" without studding and timeserting and they rarely last longer than 12,000 miles.

You talk about how hard this job was, its a shame you did all of this work and didn't do it correctly

By the way, I have been playing the lottery for 25 years and my biggest win has been $3

If I were you I would not take that car on any long family trips, avoid long hard inclines and avoid WOTs, Tick, tick, tick, tick....

There is an old saying that my Dad used to say, If you don't do it right, don't do it at all

[gm_fan]

How many miles do you have on it since you replaced the head gasket?

You just completed this job?, as you were planning it in July 2010

What would cause you to just to torque down the bolts without studding or timeserting the block?

We had discussions with you regarding studding and timeserting in this thread

http://caddyinfo.ipb...=1entry171222

We have seen Northstars be "repaired" without studding and timeserting and they rarely last longer than 12,000 miles.

You talk about how hard this job was, its a shame you did all of this work and didn't do it correctly

By the way, I have been playing the lottery for 25 years and my biggest win has been $3

If I were you I would not take that car on any long family trips, avoid long hard inclines and avoid WOTs, Tick, tick, tick, tick....

There is an old saying that my Dad used to say, If you don't do it right, don't do it at all

[gm_fan]

Yes the car has been sitting since July, as I just could not find time, since I am self employed at my Transmission business.When I took the car apart none of the head bolts were even remotely loose. As a matter of fact they were unbelievely tight. I loosened them carefully by hand and applied penetrant as soon as I could get the washer up enough under the bolts. The treads in the block were in very good condition and I cleaned them out and thread chased them.The gaskets was the problem as they had literally rotted and were coming apart. No warpage of the heads in any way and I used fel pro gaskets and replaced the heads, and Like I said. they all torqued within factory specs. The way I am looking at it is the car is good as it was when built and if I keep the coolant changed as needed, it should last ..I may regret not studding the block, but it was unbelieveably in good shape and the headgaskets were absolutely all to pieces..Again this is not a job for a backyard mechanic and the engine is very sophisticated ..Hope I dont regret my repairs..gm_fan.

[BodybyFisher]

Well keep us up to date with this.

I hope we did not neglect to impress upon you that doing the job this way was not recommended

I have seen mechanics do the job this way, and swear by it.

Keep us up to date, and good luck

[Ranger]

You might get lucky if the threads did not pull when you torqued them. Time will tell, but you are NOT supposed to chase the threads according to our old Guru. Inserting ALL the holes, even on good threads is an insurance policy.

[gm_fan]

You might get lucky if the threads did not pull when you torqued them. Time will tell, but you are NOT supposed to chase the threads according to our old Guru. Inserting ALL the holes, even on good threads is an insurance policy.

[gm_fan]

The purpose of chasing the threads is to remove debris so an accurate torque can be achieved. I did not run a tap through the holes, just a thread chaser to make sure the bolts ran down smoothly with no extra drag giving a false torque reading..time will tell on this repair, but the one thing I had going for me was the fact the car only has 63 thousand miles and the block had definitely not been inserted in any way..It was all aluminum ..and I certainly used anti-seize on the threads because of the dis-similar metals,steel and aluminum, and the anti seize also acts a a lubricant to make the bolts go in smoothly.. I just got lucky but I am very satisfied with the tightness I achieved on the head torque and I want to point out regardless of studs, inserts or what ever the torque specs are to keep you from overtighten the bolts and the question is will corrosion allow the bolts to pull later, as they are definitely holding right now...this car is a virgin one owner and I hope it works out in the future,,gm_fan

[Cadillac Jim]

One thing I recall from discussion about pulling heads on Northstars over the years is that the factory uses threadlock and sealant with torque-and-twist head bolts. This means that the bolts tend to come away with some of the metal out of the threads. Only where the threadlock breaks first all the way around and all the way down does the head bolt come out clean. The odds of this happening with all 20 with an engine that has never been apart are essentially zero. Thus I would think that this engine *has* been apart, and was probably Timeserted at some time in the past. This would explain the experiences described by gm_fan. In particular, the head gaskets were all shredded, something I haven;t heard about Northstars before; I suspect that the wrong head gaskets were used in the previous rebuild. If I'm right, his engine is now good to go.

[BodybyFisher]

When you removed the bolts did they "snap" when you broke them loose?

GM Fan, did you replace the head bolts?

You said you chased the threads to clean them up so that you didnt get a false torque reading. However, unless this torque pattern has changed there is only one 'torque' on the first pass of 30 foot pounds, the rest is torque angle, what torque spec did you use? This was posted by Barry94 a while back.

First Pass -- 40 N·m (30 lb ft)

Second Pass -- 70 Degrees

Third Pass -- 60 Degrees

Fourth Pass -- 60 Degrees (190 Degrees total)

This statement was made by our friend who is a Northstar Powertrain Engineer (you will see him referred to as the Guru)

There is an issue with galvanic corrosion over time that can make the bolts harder and harder to remove. The thread interface tends to get bonded together and is often the reason the threads in the block are damaged to some extent when removing the head bolts after 10 or 12 years....but that is why the timesert repair was developed

http://caddyinfo.ipbhost.com/index.php?showtopic=5035&st=0

Maydog made this statement, which is true

I read over that entire site. Sounds like most of the problems described came about after a trip to the mechanic. Both accounts I read there the engine was not timserted. Headbolts pulled and then they were helicoiled. Timeserts were not used, sounds like the reliability problems were caused by the technicians not understanding the reccomended service procedures

Keep in mind that while you appear to be lucky, many mechanics think they were lucky and the head gasket fails shortly thereafter. I really hope that you are lucky, I personally would be nervous

[CarlaValentine]

When you removed the bolts did they "snap" when you broke them loose?

GM Fan, did you replace the head bolts?

You said you chased the threads to clean them up so that you didnt get a false torque reading. However, unless this torque pattern has changed there is only one 'torque' on the first pass of 30 foot pounds, the rest is torque angle, what torque spec did you use? This was posted by Barry94 a while back.

First Pass -- 40 N·m (30 lb ft)

Second Pass -- 70 Degrees

Third Pass -- 60 Degrees

Fourth Pass -- 60 Degrees (190 Degrees total)

This statement was made by our friend who is a Northstar Powertrain Engineer (you will see him referred to as the Guru)

There is an issue with galvanic corrosion over time that can make the bolts harder and harder to remove. The thread interface tends to get bonded together and is often the reason the threads in the block are damaged to some extent when removing the head bolts after 10 or 12 years....but that is why the timesert repair was developed

http://caddyinfo.ipb...topic=5035&st=0

Maydog made this statement, which is true

I read over that entire site. Sounds like most of the problems described came about after a trip to the mechanic. Both accounts I read there the engine was not timserted. Headbolts pulled and then they were helicoiled. Timeserts were not used, sounds like the reliability problems were caused by the technicians not understanding the reccomended service procedures

Keep in mind that while you appear to be lucky, many mechanics think they were lucky and the head gasket fails shortly thereafter. I really hope that you are lucky, I personally would be nervous

Nervous doesn't even describe how I would feel driving that car. I get anxiety driving with a slightly under-inflated tire, let alone the possibility of head bolt failure after ALL that work!

I have to admit though, seeing all this hg related stuff on the boards lately has seriously got me considering finding a northstar with a blown hg, just so I can attempt the job myself. I certainly don't wanna try it on my daily driver though...unless it becomes necessary.

[gm_fan]

I have done mechanic work for 40 years. I have tightened more bolts that is in that whole cadillac I am working on 20 times over. But I am confident in the repair I have done and the bolts[new] were tightened to 30 foot pounds and then I used a torque angle meter to complete the job as specified . My point is I have enough experience to tell when a bolt is tightened or if it is pulling...these all tightened up nicely and if it fails later, so be it..It is a 1998 model car ,even though it has the original window sticker in the glove box for 49,860.00 its still an old car . I feel good about the repair as like I said previously, the head gaskets were rotten and falling to pieces, so I believe this was the main issue with this car.I am perfectly willing to admit to anyone if I made a wrong call, but that remains to be seen..I do appreciate all the input on this site, but 40 years experience has to be worth something..The last 15 years transmissions only,,,thanks gm_fan

[BodybyFisher]

Listen I am 57 years old myself and have worked on Cadillacs and Packards since I was 6.

It is not necessary to IMPRESS us with your mechanical experience, we are not looking for resumes. We believe it or not have quite a bit of experience here ourselves.

We have been here for over 10 years working on and sharing experience of head gasket jobs

We have had GM techs here who have worked on the Northstar (Ian, AJ) and who have helped to design the Northstar (guru, John Sundeen)

We have had a Northstar Powertain Engineer here who was on the design team, his name was Al Cline, and he was a genious, he is referred to as "the guru" here. The guru spent a long time here passing along his wisdom and experience and we hold him in high esteem

The guru worked on a team who designed the timesert, because threads were failing when a head gasket was done.

We now have a STUD solution, that looks incredible, that you researched here

We have seen disasters, where many members did not have their NS head gasket repaired correctly (timeserted) and it failed in short order.

If you choose to IGNORE all of that, so be it, but we are NOT here to try to impress eachother with our experience.

You did NOT repair your Northstar correctly, whether you think so or NOT, and only time will tell whether it will last, NOT the spewing of how experienced you are.

I only wish you Good Luck, but if you sell it, make sure you tell them it was not repaired correctly.

One thing I want to tell you is this, your 40 years of experience is great, but with the Northstar, you need to RELEARN everything, and keep an open mind, YOU do not have an open mind, you are rigid. I hope that works for you

[KHE]

..and I certainly used anti-seize on the threads because of the dis-similar metals,steel and aluminum, and the anti seize also acts a a lubricant to make the bolts go in smoothly.. I just got lucky but I am very satisfied with the tightness I achieved on the head torque and I want to point out regardless of studs, inserts or what ever the torque specs are to keep you from overtighten the bolts and the question is will corrosion allow the bolts to pull later, as they are definitely holding right now...this car is a virgin one owner and I hope it works out in the future,,gm_fan

Sounds like you re-used the old head bolts. Sorry to say, the repair will not last. The head bolts must be replaced when removed. The head bolts have a microencapsulated threadlocker that is applied to the threads and the underside of the washer. There is no way to duplicate that coating in the field - that's why the shop manual states to replace the headbolts. Chasing the threads is not recommended as the factory threads are rolled threads and chasing the threads will remove some material compromising the strength of the threads in the block.

By applying anti-sieze on the threads, the bolts will not be locked and may loosen up over time causing the headgaskets to leak again.

[BodybyFisher]

Here is a thread from GM Insider that will make the hair on the back of your neck stand up. I do believe you have a 98. You'll notice how they said to head over to Caddyinfo, the 'source' of all things when it comes to Cadillac!

http://www.gminsiden...d-gasket-74464/

[scott y]

Dang...now I'm worried,after reading all that.I wonder if I should start browsing around for some fresh wheels before the snows and evil winds start to "blow".

[Cadillac Jim]

Scott F -- Your description of the work was very atypical in at least two respects: the head gaskets, in your words, "had literally rotted and were coming apart," and the head bolts came out just like head bolts from an iron block. This says to me that there was an earlier repair in which the head gaskets were not appropriate for an all-aluminum engine but the head bolt threads were Timserted or otherwise repaired. When you chased the threads, were the shavings aluminum? Could they have been Timesert material such as mild steel? If so, then you likely won't have a problem.

I would just get a plan for fresh gaskets and a Timesert or Bigsert kit and be prepared. After doing the job once, if you have the right facilities like a warm place to work, an engine crane (rent?), and an engine stand (rent?) you can probably do the job in a day, two days max. My mechanic did a R&R of my 1997 Eldorado engine in about a half-day when I got my remanufactured engine in 2006. That included changing over the fuel injection and cam covers and installing all the little things like a new water pump and idler, etc., so this is more that you would do to fix a pulled head bolt, other than the obvious - R&R the heads and install the Timeserts, which is an afternoon or so in itself.

[BodybyFisher]

By the way, Kevin, I re-read this thread and they fellow DID replace the bolts, but then it appears he used anti-seize on them.

[scott y]

Scott F -- Your description of the work was very atypical in at least two respects: the head gaskets, in your words, "had literally rotted and were coming apart," and the head bolts came out just like head bolts from an iron block. This says to me that there was an earlier repair in which the head gaskets were not appropriate for an all-aluminum engine but the head bolt threads were Timserted or otherwise repaired. When you chased the threads, were the shavings aluminum? Could they have been Timesert material such as mild steel? If so, then you likely won't have a problem.

I would just get a plan for fresh gaskets and a Timesert or Bigsert kit and be prepared. After doing the job once, if you have the right facilities like a warm place to work, an engine crane (rent?), and an engine stand (rent?) you can probably do the job in a day, two days max. My mechanic did a R&R of my 1997 Eldorado engine in about a half-day when I got my remanufactured engine in 2006. That included changing over the fuel injection and cam covers and installing all the little things like a new water pump and idler, etc., so this is more that you would do to fix a pulled head bolt, other than the obvious - R&R the heads and install the Timeserts, which is an afternoon or so in itself.

[scott y]

Sorry Jims_97_Etc but I think you're mistaking me for gmfan, I was merely reading the link that BBf posted and it's starting to scare me about the future of my 94 STS, wondering "if and when" the bolts may pull...

[BodybyFisher]

Sorry Jims_97_Etc but I think you're mistaking me for gmfan, I was merely reading the link that BBf posted and it's starting to scare me about the future of my 94 STS, wondering "if and when" the bolts may pull...

Don't get yourself worried about it, just drive it. I was VERY reluctant to post the link to GMInsider for fear of freaking someone out. But its NOT something we don't know already, its just painted different.

[BodybyFisher]

You know its interesting Jim and Kevin, GMFAN said his bolts came out just like cast iron bolts.

I was my understanding that if the integrity of the bolts is good, there will be a SNAP, is that correct? I previously asked GMFAN if he got a SNAP on removal of the head bolts?

He did say by the way that he didn't believe the block was timeserted. Kevin is it obvious that a block has been timeserted?

[KHE]

You know its interesting Jim and Kevin, GMFAN said his bolts came out just like cast iron bolts.

I was my understanding that if the integrity of the bolts is good, there will be a SNAP, is that correct? I previously asked GMFAN if he got a SNAP on removal of the head bolts?

He did say by the way that he didn't believe the block was timeserted. Kevin is it obvious that a block has been timeserted?

When breaking loose the headbolts, there will be a snap/pop sound if they were holding and not pulled. I think the noise is a combination of the threadlocker and the torque of the bolts.

If the block has been Timeserted, it will be visible through the thread bolt hole. A magnet can also be used to confirm the presence of the insert.

[KHE]

Sorry Jims_97_Etc but I think you're mistaking me for gmfan, I was merely reading the link that BBf posted and it's starting to scare me about the future of my 94 STS, wondering "if and when" the bolts may pull...

Don't lose any sleep over it - just drive it and keep the coolant changed. The headbolt issue is exaggerated due to internet forums as people rarely seek the internet to brag on how reliable their car is.