Northstar stud problem

['90 Eldo]

I just learned of a car for sale that has a Northstar engine with a problem where the studs are pulling out of the block,apparently someone overtorqued them? Can this be fixed? If so can it be dependable?

[dkozloski]

There must be a thousand posts on this subject by now. Do a search on headbolts, head gaskets, Time-Serts, and blown gaskets. By the way, it is bolts and not studs that have thread problems.

['90 Eldo]

Thanks for the input. I just heard the guy say it had studs I don't know much about the engine. I will look up the info you mentioned on it . I'm a newbie so I appreciate your patience here.

[zonie77]

Look in the tech section for the head gasket post. There is a link to an illustrated article on installing timeserts.

[dkozloski]

'90Eldo, to answer you question in a nutshell, some Northstar engines have problems with pulled threads and blown head gaskets. They can be fixed good as new by a reasonably handy mechanic that can follow directions. Some of the tooling required is an added expense.

[peteski]

90 Eldo - if your car is same as your name: 1990 Eldo, then it doesn't have a Northstar engine. So, you wouldn't have the "stud problem"

['90 Eldo]

The car I'm referring to is a newer Sedan DeVille that is about to be towed. The car is nice other than the engine problem. I thought it would be worth fixing and reselling if it can be dependable. Is the problem symptomatic of the engine itself or is this something mechanics are doing to the engine when they are r&r ing the heads? At any rate I appreciate your input and I will look into it further with a mechanic,thanks again.

[nota]

has any one found a source of studs to replace N* head bolts?? in proper grade ect
yes I know about time-certs still I like the idea of never ever removing the studs
from the problemmatic alloy block, just undo the top of stud nuts
IF any of my extra N* blocks are lucky enuff to unbolt without pulling out threads
btw main cap studs would be a good idea tooo

[dkozloski]

It's much trickier than it seems. Do some searches on this subject on this forum and you become Bbob educated like the rest of us. Basically; the heads, the head gasket, the crankcase, and the torque to yield bolts are all together a highly engineered and tested system that is not to be modified by the unwashed masses without serious risk of disaster.

[STS 310]

Originally Posted by dkozloski

It's much trickier than it seems. Do some searches on this subject on this forum and you become Bbob educated like the rest of us. Basically; the heads, the head gasket, the crankcase, and the torque to yield bolts are all together a highly engineered and tested system that is not to be modified by the unwashed masses without serious risk of disaster.

Well said dkoz....

['90 Eldo]

Experimenting with a replacement stud sounds tempting. I have had some experience in aluminum engines where the studs themselves will "stretch" I suppose more likely under higher compression ratios. This is a problem in Porsche engines which are being fixed using Dilivar (whatever that is) studs as a replacement. But as you stated there is the head gasket,and probably clearance problems to contend with,and this is a very expensive engine to be playing with.

Thanks for your input.

[odarodle]

You can re tap using a boot or Check with a machine shop, They have the equipment to do the job right.......

[denscor]

Originally Posted by nota

has any one found a source of studs to replace N* head bolts?? in proper grade ect
yes I know about time-certs still I like the idea of never ever removing the studs
from the problemmatic alloy block, just undo the top of stud nuts
IF any of my extra N* blocks are lucky enuff to unbolt without pulling out threads
btw main cap studs would be a good idea tooo

I called ARP today and inquired if they carried Head Studs for the N* to my surprise the rep I spoke to new exactly what I was looking for.
He said they have a Kit but it's not labeled for the northstar but for a VW 16 valve DOHC and the part number is: 204-4204 and you will need to of these kits.
He also mentioned that he has been selling these kits to Cadillac dealers for several years. Hmmmm interesting.
The kit has 10 studs, molylube & 10 twelve point nuts. I looked into the specs of these units and they have the M11 x 1.5mm thread and are 6.5" long (165mm) for the block side.(Stock bolts for mine are listed at 152mm) Didn't get the specs for the nut side thread, Sorry.
These babies are rated for 190,000 PSI tensile strength. WOW! ARP
mentioned Timeserts were a necessity.


Hope this helps!!!!!!!!!!!!!!

[davesdeville]

^^Hmm I read that on a Fiero forum awhile ago. Nice to know that ARP itself says the same thing.

[parts68]

thats funny when I said the same thing about head studs on another post I got flamed.
How are they torqued?by measuring stretch? torque to yeild?