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Blue Devil Head Gasket Sealer WORKED in 99 Northstar


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As most everyone knows, the 32V Northstar had some bad years for head gaskets. My father has a 99 Deville w/ 104K (Clean car/ cold A/C etc.) that is stored 6 months out of the year. Upon pulling it out of climate controled storage a few weeks ago, it began giving us all the signs of a bad head gasket. Pre mature pressure in the radiator (tank), leaking oil, over heating, bad mis fire and the hint of white smoke out the dual exhaust, codes on the dash came up random mis fire.

Had it tested by a trusted mechanic and he confirmed it was the head gasket leaking at #3 cylinder. My understanding is that you are better off swapping the engine out with a salvage one (with a warranty) then trying to repair the current engine. Either way we were looking at $2,500 - $3,500 to get the car back on the road. (GM wanted $6,500 to fix and basically laughed at the fact I called) You could only drive it a short distance because it would over heat, not to mention clog up the cat's etc.

I have used the Blue Devil head gasket sealer in 2 vehicles I have had (long story on both of them, but anyway) one was a 99 Caravan 3.0L and one was a 95 Deville with the pre Northstar Engine. Blue Devil worked on them both and they are still on the road. Both of them clearly had blown head gaskets. The Caravan belonged to someone at church and she was looking at a $2,500 repair. Months later the van is running with no problems.

On the 99 Northstar I was not equipped to follow the process of adding the Blue Devil at the location we were at, you need to drain the radiator, flush, remove the thermostat, etc. I had limited tools so I asked the Mechanic who worked on the car to follow the directions exactly for one hour shop time, of course not holding him accountable for any results.

Blue Devil seemed to work!!

500+ miles later, the car is still running perfect. Not over heating, no mis fire, no white smoke, no loss of coolent, oil , anything, hard to believe this stuff actually works. Now I know the long term effects could probably be challenged, I have read mixed reviews, but some people have said they have driven the car for years with no problems. The bottom line is that for $60.00 you can put off a major repair or maybe never repair. The other option was to do the engine swap, so we really had nothing to lose. If we need to fix it down the road, we just bought time i guess, but so far, it's perfect.

On another note, shame on GM for not recalling these Northstar Engines, I have found documentation as the relate to the GM TSB's that the NS engine for certain years has a ONE IN FOUR failure rate on the head gaskets. How is that acceptable? There are many discussions about bolt lengths, strength of the block, not maintaining the anti freeze to dealer spec eats the aluminum if the car is stored and when you start it, the head simply separates from the block - any way; lots of theories. Bottom line is that GM should have fixed them, especially on their flag ship fleet - Caddy.

If you're in a situation with a Northstar engine, try the Blue Devil; they claim an 85% success rate on the Northstar - even if it get's you buy for some time to save up and fix it, or whatever.

PS: I have nothing to do with Blue Devil, but 3 for 3 on a fix in a can is pretty darn good.

Thanks...

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Although I can't recommend that approach as a permanent solution I am happy to hear you are pleased with the result. Please continue to keep us updated as to how it proceeds over time.

I disagree on several points you make. The approved repair for head gasket or stripped head bolt is not a used replacement, but is a thread repair and head gasket replacement. Due to the complexity of the work, it does cost more than it is economical to pay for repair of older models.

GM did in fact stand behind and support the Northstar V8, and would repair head gaskets or other items when the issue happened under warranty. Obviously your 99 Cadillac at 104K was apparently no longer under warranty coverage. No surprise then that it would be an out of pocket repair.

I am surprised your Dealer would laugh when you called about having the car repaired; my dealer is happy to have the work. Maybe you need a new dealer.

I would like to see your documentation on NS failure rate if you have some. Please email it to admin@caddyinfo.com

I have found documentation as the relate to the GM TSB's that the NS engine for certain years has a ONE IN FOUR failure rate on the head gaskets

Bruce

2016 Cadillac ATS-V gray/black

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I can see people "fixing" their caddys before they sell them now to sell them as "runs strong"

* 1966 Deville Convertible

* 2007 Escalade ESV Black on Black

* 1996 Fleetwood Brougham Black on Black V4P -Gone
* 1983 Coupe Deville Street/Show Lowrider -Gone

* 1970 Calais 4dr Hardtop GONE
* 2000 Deville DTS - Silver with Black Leather and SE grille GONE
* 1999 Seville STS - Pearl Red GONE

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have never seen a professional mechanic say they feel comfortable using miracle headgasket repair in a can. many threads online from amateurs saying cure in a can works. the theory of adding a slurry to coolant to seal leaks is valid. maybe on a hose connection or cracked plastic fitting. not cool with a leaking steel headgasket and aluminum block/heads and pulled head bolts. way too much thermal expansion going on there.

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Its a band-aid for an ax wound and I would be terrified to take the car on a short road trip out of town. The amount of head gaskets I have seen and what Dexcool does destroys, eats away the head gasket and crossover gaskets. Ya everyone want to save some cash and gamble but in the end time, money, frustration its better off fixing the smoking gun the head gasket that's decaying.

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I don't mind you posting your experience, I do mind you posting your opinion, this is opinion that we did not ask for and that I disagree with. GM has a responsibility to repair/replace these engines during the warranty period, what was that on a 99 4 years/100,000 miles? The 99 is now 12 years old. As the 93 - 99 Northstar ages, the % of failures will naturally increase. NOW, what I want you to do, is to take the car on a LONG, high speed trip with lots of WOTs in 95 degree heat, I doubt very much that it lasts the trip, make it about 1000 miles.

The internet is the focal point of problems people dont come to the internet to report how happy they are, so what you find on the internet is natural bias toward problems. You will also find bad statements about Dexcool, but there are always reasons for problems.

This is opinion

On another note, shame on GM for not recalling these Northstar Engines, I have found documentation as the relate to the GM TSB's that the NS engine for certain years has a ONE IN FOUR failure rate on the head gaskets. How is that acceptable? There are many discussions about bolt lengths, strength of the block, not maintaining the anti freeze to dealer spec eats the aluminum if the car is stored and when you start it, the head simply separates from the block - any way; lots of theories. Bottom line is that GM should have fixed them, especially on their flag ship fleet - Caddy.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Its a band-aid for an ax wound and I would be terrified to take the car on a short road trip out of town. The amount of head gaskets I have seen and what Dexcool does destroys, eats away the head gasket and crossover gaskets. Ya everyone want to save some cash and gamble but in the end time, money, frustration its better off fixing the smoking gun the head gasket that's decaying.

It is not the DEXCOOL in my opinion. However allowing the DEXCOOL to remain long after is loses its corrosion protection will accelerate a failure.

I believe the head gaskets fail from multiple creeping causes, heat being the most dangerous cause that degrades the block aluminum over time

As far as the crossover gaskets are concerned they CRACK from heat and age then begin to leak, that type of deterioration is not caused by Dexcool. I have photos of mine, the crossover seals were badly cracked and deteriorated

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Mike...

You are wrong... :P

I came here to say.... "I LOVE MY CADILLAC"... :hatsoff::yupi3ti::bluesbrothers:

Just playing with you.... :D

I don;t like "UNSUPPORTED OPINIONS" either...

Either back it up or retract it...

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Sorry Jim, I stand corrected

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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....and what Dexcool does destroys, eats away the head gasket and crossover gaskets.

There is no scientific or statistical basis for that "urban legend" misinformation.

All a reasonable person has to question is; why GM continues to factory fill cooling systems with Dex-Cool sixteen years after Dex-Cool was developed? And the only reasonable answer would be; because Dex-Cool is NOT guilty of any of the cooling system problems it has been or will be accused of.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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Dex-Cool is some pretty amazing stuff. It not only attacks just the HG's, but it only does it on Northstars. I don't know how they made this stuff, but it is amazingly sophisticated for a liquid.

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My head bolts did not pull in my 94 Concours until I had 166,000 miles. I did not think that GM owed me anything. I only paid $6000 for it and drove it for over 100,000 miles. It was the best car I ever owned. In an older northstar over 100,000 miles it is not a question of IF the headbolts will fail it is WHEN. Do I think it is a defect? Maybe if it failed under warranty. It is an issue that was improved on 2000 & up caddys. Yes 99 had a high failure rate but it was due to a faulty block if I remember right and it was fixed under warranty in a TSB. Do a search on here and you might find the thread. I only paid $4000 for my 97 Deville and I almost have 158,000 total miles on it and almost 100,000 since I bought it. It has no leaks and maybe uses 1 quart between oil changes. I expect it to last over 200,000 miles at this rate. I love my Caddy's, the 94 is my parts car for the 97 now.

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My head bolts did not pull in my 94 Concours until I had 166,000 miles. I did not think that GM owed me anything. I only paid $6000 for it and drove it for over 100,000 miles. It was the best car I ever owned. In an older northstar over 100,000 miles it is not a question of IF the headbolts will fail it is WHEN. Do I think it is a defect? Maybe if it failed under warranty. It is an issue that was improved on 2000 & up caddys. Yes 99 had a high failure rate but it was due to a faulty block if I remember right and it was fixed under warranty in a TSB. Do a search on here and you might find the thread. I only paid $4000 for my 97 Deville and I almost have 158,000 total miles on it and almost 100,000 since I bought it. It has no leaks and maybe uses 1 quart between oil changes. I expect it to last over 200,000 miles at this rate. I love my Caddy's, the 94 is my parts car for the 97 now.

Paul:

I applaud your experience with Northstar engines. But I have to disagree with your assessment of headbolt failure being a cause rather than an effect.

Take a look at this thread (on another Cadillac board) and specifically posts #7 and #11.

http://www.cadillacforums.com/forums/cadillac-seville-cadillac-eldorado-forum/234256-why-do-i-have-coolant-my.html

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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With regard to that recall for 99, that was ONLY applicable to a specific VIN number run

See this link

http://caddyinfo.ipb...&hl=recall&st=0

With regard to Dexcool eating the head gaskets. The Northstar has an open deck wet sleeve design, I posted a photo. Recently I have seen someone suggest that a closed deck would have been better, but stating that without the benefit of the designer's ideas / reasoning is Monday morning quarterbacking. In the open deck wet sleeve design the coolant contacts the head gasket, I can only imagine that over time acidic or non acidic the heated coolant (and this is located at the hottest area of the sleeve) will eventually deteriorate the head gasket above the open coolant passage. Personally, I am not surprised to see deterioration in that location. However, while that portion of the head gasket can be deteriorated there is still a section sealing the sleeve between the combustion chamber and coolant passage. The question in my mind is, if the portion of head gasket above the coolant passage gets deteriorated, can that negatively impact the head gaskets sealing capability or even allow coolant to seep or be wicked into the head gasket eventually causing the block aluminum to corrode/soften/deteriorate.

Why had a gasket not been designed that will better resist coolant deterioration above the open coolant passage for this engine? Is an aftermaket head gasket like this a better alternative > http://www.cometic.com/est.aspx

1569_3mg.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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With regard to that recall for 99, that was ONLY applicable to a specific VIN number run

See this link

http://caddyinfo.ipb...&hl=recall&st=0

With regard to Dexcool eating the head gaskets. The Northstar has an open deck wet sleeve design, I posted a photo. Recently I have seen someone suggest that a closed deck would have been better, but stating that without the benefit of the designer's ideas / reasoning is Monday morning quarterbacking. In the open deck wet sleeve design the coolant contacts the head gasket, I can only imagine that over time acidic or non acidic the heated coolant (and this is located at the hottest area of the sleeve) will eventually deteriorate the head gasket above the open coolant passage. Personally, I am not surprised to see deterioration in that location. However, while that portion of the head gasket can be deteriorated there is still a section sealing the sleeve between the combustion chamber and coolant passage. The question in my mind is, if the portion of head gasket above the coolant passage gets deteriorated, can that negatively impact the head gaskets sealing capability or even allow coolant to seep or be wicked into the head gasket eventually causing the block aluminum to corrode/soften/deteriorate.

Why had a gasket not been designed that will better resist coolant deterioration above the open coolant passage for this engine? Is an aftermaket head gasket like this a better alternative > http://www.cometic.com/est.aspx

1569_3mg.jpg

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What are you saying bbob?, you replyed and there is no text, can I help?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I have to be honest. - The more I read this board, the more worried I get that my '96 is going to pull it's headbolts. :(About a year ago, I decided the engine is too old to perform (WOT's) anymore. It may be OK for a 10 year old car, but my position is that once it's past 15 years, I'd rather have a little oil getting past the rings that put that much pressure on the headbolts with a WOT. (Plus I drive it so little) My temperatures still seem normal, however several weeks ago, someone posted some temperature readings that they reported as unusual - which were exectly mine too). Thankfully BBF corrected that person, and mentioned they were perfectly normal -phew!!. The only other (in my opinion) preventative action I take is to open the hod on a hot day on a 220 degree engine.

I can imagine the head gasket sealer can work if the failure is the result of a corroded gasket (rust bubbles). But there is no way of knowing what the cause of the HG failure is, so it is a risk.

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I have one question: Has anyone actually proved that Northstar head bolts pull or separate from the block?

It seems to me that claiming Northstar head bolts pull and therefore cause head gasket failure is an unsupported theory. I have yet to see anyone post any proof.

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I have one question: Has anyone actually proved that Northstar head bolts pull or separate from the block?

It seems to me that claiming Northstar head bolts pull and therefore cause head gasket failure is an unsupported theory. I have yet to see anyone post any proof.

I think that theory was proven but I can not remember when it was discussed. Wasn't it the corrosion of the head gasket from antifreeze being neglected that caused the head bolts to pull? If the head bolts were not a problem then why the better/bigger bolt change?

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I have revised my thinking, on this, I don't think the coolant necessarily has to be left in beyond its change interval to cause a problem, I think that the head gasket that is visible to the coolant in the coolant passage takes a beating and eventually coolant gets to where it should not be causing corrosion that with heat degrades the aluminum surrounding the bolts.

The reason I say this is because I know that my coolant was not left in too long in my 96

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I have one question: Has anyone actually proved that Northstar head bolts pull or separate from the block?

It seems to me that claiming Northstar head bolts pull and therefore cause head gasket failure is an unsupported theory. I have yet to see anyone post any proof.

I have been singing that song for years but very few seem to enjoy the lyrics enough to repeat them.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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I have revised my thinking, on this, I don't think the coolant necessarily has to be left in beyond its change interval to cause a problem, I think that the head gasket that is visible to the coolant in the coolant passage takes a beating and eventually coolant gets to where it should not be causing corrosion that with heat degrades the aluminum surrounding the bolts.

The reason I say this is because I know that my coolant was not left in too long in my 96

I remember reading a long discussion about this topic on the Cadillac Forums website when the Guru was around and he explained how head bolts are encased in order to protect them from coolant seepage. He said those who claim head bolts actually pulled or separated from the head are actually seeing the results of damaged threads caused by removing the head bolts in order to replace the head gasket, which is why Time-Serts are necessary. I've seen many parrot the pulled head bolts claim, yet no one has provided any proof. The Guru did say that the head gasket is a week point and that eventually it could fail due to thermocycling. Here is a link where Poobah mentioned thermocycling back in 2007 and in post #6 I also mentioned what the Guru discussed.

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Interesting stuff. Jim, I dont think I ever understood where you were going with your idea until today

I have never done a head gasket, but I recall members saying that they found bolts loose, wouldnt that tend to go against the thread wiped by removing them theory?, or could it be a little of both causes?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I had my 95 SLS N* on the road for 336,000 mi with no head gasket problems. Drove it into a telephone pole drunk one night and the head gasket was still good.

Caddy_Grill.jpg2008 DTS
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