: Is it just me or does it seem like there are a lot more bad head gaskets, esp 2000+



jimsbox
03-31-11, 05:31 AM
Is it just me or does it seem like there are a lot more bad head gaskets, esp 2000+ lately? I don't remember there being that many popping up until very recently.

Jim

ThumperPup
03-31-11, 09:11 AM
jim your right there are alot more 2000+ going bad
it comes down to where now some of us think it has nothing to do with the changes they made to try and fix the HG issue over the years with the Northstar atlest he Eldo Seville and Deville Northstar engines
it comes down to time and age that they seem ot be fealing more over the years from what i take on others take about it threw reading the threads and all i feel this is the way it is also
i think its a matter of time between now and when we see and hear about a 04 that goes bad
im still waiting for one to pop up i thout we had someone in here a few months back with an 04 that went bad but i guess we didn't i dont think

and because of this i always said if i get another seville it will be an 04 for because they fixed the hg issue that year with the new coraser threads and all
well im not thinking that way anymore its bound to happen just time will tell
if i get another seville its going to be a 02.5 or 03 sts

jimsbox
03-31-11, 10:53 AM
I wonder if maybe GM knows more than it is owning up to and that may be why they are shelving the Northstar for good. It is still a very young engine, not even 20 years old, how long has the 350 been on the market? It's too bad, I really like the engine and except for the head gaskets they are bullet proof. It may also just be a matter of perception because I really have no idea, nor does anyone outside of GM what the overall failure rate is compared to those that don't. I would bet any amount of money that any mass produced engine with over 100000 units sold will have some head gasket failures. Alas, it pains me see so many young people buying their first Cadillac and wanting to know why it overheated within a day or two of purchase.

Jim

Ranger
03-31-11, 11:42 AM
The 2000+ engines ARE getting older so I suspect we'll see a few popping up now and then. They are not immune. I can't say that I've noticed a lot though. Certainly not like the pre 2000's. Especially the '99's.

97EldoCoupe
03-31-11, 01:22 PM
The Northstar is a great engine. I don't think they're any more prone to HG failure than anything else out there with the exception of two key factors:

- head bolt & thread design
- open deck

HG's give out on many, MANY vehicles, especially at the age of these late '90's Caddys...

RippyPartsDept
03-31-11, 01:43 PM
there's two designs in 2004 ... there's no VIN break or production date break noted in my parts catalog

the only way you can tell is by inspecting the bolts to see if they have the coarse thread or not

we have done headgaskets on one or two of these cars w/ the coarser factory threads but it was not due to bolts pulling from the block
and we don't tap/insert the block on those either... just new parts put back on ... still a lot of labor to drop the powertrain though

ThumperPup
03-31-11, 02:57 PM
wow so if you got a 04 in with a coraser thread you woud not drill and tap the block and insert
i would think that it does not matter hwo the threading is still its the same just difrant thread in block i dont know if id do it without inserting but maybe this is why jake does not have anything for the 04 engine atleast at first glance cause the descrition when ordering studds on his website askes what years and i dont see where it has a 04 stud kit
but still why not insert the block atleast

jimsbox
03-31-11, 03:18 PM
Actually, if I am not mistaken, the thread size and count for the Suregrip Studs is the same as 04+ threads and you should be able to put the studs in without any machining of the block.

ThumperPup
03-31-11, 03:33 PM
ah ok so if they sirted the block on an 04 then they would have to use big sirts cause its already thicker then the 03 and older then is that corect

jimsbox
03-31-11, 04:22 PM
As I understand it, yes

NHRATA01
03-31-11, 04:34 PM
The Northstar is a great engine. I don't think they're any more prone to HG failure than anything else out there with the exception of two key factors:

- head bolt & thread design
- open deck

HG's give out on many, MANY vehicles, especially at the age of these late '90's Caddys...

They are most definitely more prone to HG failure. Head bolt design and open deck are part of the reason, but a major one seems to be poor block castings with excessive porosity. Threads do not just pull out of normal aluminum blocks. The LSx motors have been around since '97 in performance vehicles and in huge numbers of the full-size trucks since '99. Many in either case seeing higher mileage and more severe duty than your average Caddy. HG's simply aren't a problem. A lot of foreign manufacturers use an open-deck design and an Al block (such as Nissan's VQ series V6), again, not HG issues to this level.

RippyPartsDept
03-31-11, 04:50 PM
that all sounds about right... the parts catalog says M11x2 is the size of the new bolts

97EldoCoupe
04-01-11, 04:56 PM
Whoa back the truck up a minute - M11x2.0 is the same diameter bolt as M11x.1.5 the threads are just coarser (less threads per inch).

5/8x11 is what my studs are and that is about as extreme as you can go without taking too much meat out of the block.

You still have to drill and tap to use my studs on the 2004+. I know they will work up to 2005, I have never done anything past '04 yet but I have sold quite a few sets for 04/05. I will someday work on the 06-2010 blocks and find out what revisions are necessary (if any) to make the kits for the newer engines.

The M11x2.0 thread pitch is not the end of the thread problem. I didn't trust the holes on my '04 Bonneville GXP, some aluminum came out, so I studded it. I expect to see a drop in kit sales for the '04+ but not entirely. When it's your paycheck it's difficult to wish for no problems with the threads but as Cadillac owners we all would be very lucky if the thread pitch redesign would have been the answer to the stripped threads. For the most part, I believe it is. :D

RippyPartsDept
04-01-11, 05:27 PM
yeah, like I said we have done (i think) two and haven't inserted the block on those

i think they were actually on 2006 DTS cars also

ThumperPup
04-01-11, 06:11 PM
still i don't understand why not sirt the block on an 04 or 05 at your dealer rippy wouldnt it still be prone to the same issue of stripping the block when torqing the bolts back down ?

RippyPartsDept
04-01-11, 07:12 PM
we haven't seen any stripped bolt threads on these newer blocks with the coarser threads - just two gasket failures

i'll ask my HG guru on monday if you'd like me to... and for all i know i could be totally wrong

ThumperPup
04-01-11, 07:39 PM
it's just a curiosity if you could ask when you get a chance no need to rush on it just curious about it and all
guess maybe that could be a good thing for those who have 04 and 05 blocks probalby what about 6 hours of work less so thats what problaby like 500 dollars less to do the hg job or something so guess its a good thing
but i know if i had a 05 deville or an 04 or an 04 seville and someone came to me saying oh you don't have to do the drill and tap and thread the block
on these they where better i think i would still rather have it done why ll the drive train is dropped just for my own peace of mind

ThumperPup
04-01-11, 07:41 PM
hey rippy off topic here but i was thinking about sending you a PM saying that the cashier must not have put a . between the 8 and the 2
and that my credit card was charted 9825 dollars when it should have been 98.25 lol
but i feel that might have not been a good joke cause i think before you contact me you would have contacted the job and would have put a panic threw lol

RippyPartsDept
04-01-11, 07:52 PM
yeah that would have been a good april's fools joke... but you're right that i might have freaked out because stranger things have happened before

although now that i think about it a bit

i don't think that they use the . on the credit card machine... i think it puts it in automatically so to charge that much they would have had to add two zeros after typing in the 9825

still would have probably stopped my heart, so thanks for keeping that one on the shelf

RippyPartsDept
04-01-11, 07:56 PM
and back on topic: if it was my car i would still want the studs in it if you're tearing it down that far

but on those two that we did it was under GM warranty so i guess i should really double check to make sure that's what we did so people don't get the wrong idea taking what I say I remember as actual fact

ThumperPup
04-01-11, 08:09 PM
yeah that would have been a good april's fools joke... but you're right that i might have freaked out because stranger things have happened before

although now that i think about it a bit

i don't think that they use the . on the credit card machine... i think it puts it in automatically so to charge that much they would have had to add two zeros after typing in the 9825

still would have probably stopped my heart, so thanks for keeping that one on the shelf

nope dont want to stop your heart i think if i did that id have a few ppl here ready to kill me for looseing there part hook up lol

ThumperPup
04-01-11, 08:10 PM
and back on topic: if it was my car i would still want the studs in it if you're tearing it down that far

but on those two that we did it was under GM warranty so i guess i should really double check to make sure that's what we did so people don't get the wrong idea taking what I say I remember as actual fact

i would have thout at the price it cost to tear it down and do the work that GM probalby would have just sent you out a new engine
atleast i thout thats what they did when these went bad but maybe thats not the case

RippyPartsDept
04-01-11, 09:21 PM
at first they did, but then they devised the timesert repair

jimsbox
04-02-11, 03:03 PM
Jake, ever consider putting out a kit with the M11x2.0 threads so don't have to drill and tap 04+ blocks?

97EldoCoupe
04-02-11, 08:13 PM
No I have not Jimsbox, but that would be a good idea. Then if those studs pull the threads, the Suregrips would take over.

edb150
04-03-11, 12:47 PM
I have seen 2 2004 blocks with failed threads. 1 car we did with jakes studs and the other was another shop that was doing hgs and stripped 1 hole on reassembly. he borrowed my tools and inserted 1 hole and used a 2000 headbolt in the insert and the course thread in the other 9 holes. The customer had no money to spend .The car we did had only 2-3 threads that were questionable.

RippyPartsDept
04-03-11, 07:39 PM
was it a 2004 block w/ m11x2 threads??

maeng9981
04-04-11, 03:47 AM
In my case, unlike lots of 97-99, bolts were fine, it was just the gaskets that were corroded to the point that it looks so nasty. Both banks. I am guessing that the engine was neglected on coolant changes. Previous owner followed the 5-year / 150,000 mile thing. I replaced coolant right after I bought it but I think it was already too late.