Head Stud problems in a 964 3.6?

Mikey83835 · Mikey83835's Garage

I am on the verge of buying a 92 3.6 motor for my lightweight outlaw-type '74 Targa, motor has all the rebuild receipts from 2005 and seems to have logged 14k miles since then, had 128k at rebuild,

All the right stuff including the new style cvlinders/pistons, but the head studs were not replaced, this seems to be a huge concern for the 3.0 motors, and the 3.2 motors to a lesser extent, they are not usually replaced at rebuild on a 3.6?

Motor is out of car so PPI might be difficult, but leakdown numbers look good,

Opinions?

Mikey83835 · Mikey83835's Garage

No opinions?

safe · safe's Garage

Usually the studs are OK, those engines (3.6s) I have come across has had all steel studs, not the dilavar crap.
On the other hand I have fitted Supertec studs to a 993 3.6 and a 964 3.6 because there was envidence of leakage and movement between the cylinder and heads.

Dan J · 10-01-2013, 03:53 AM

A 92 964 will have dilavar studs top and bottom. They will occasionally break
though not with the frequency of 3.0-3.2 motors. Do a leakdown test if you're concerned

porterdog · 10-01-2013, 07:11 AM

Discovered one bad one on my car when I first got it (~112k). Running one short, just crossed 140k.

umgang · 10-01-2013, 07:41 AM

They do break.
Problem is corrosion of studs themselves- internally, that snaps the ends off with bolts intact.
I have a 1991 964, 186,000 miles and just found three stud ends with bolts attached in the valve covers when preparing to do a valve adjustment.

safe · safe's Garage

Quote:

Originally Posted by umgang

They do break.
Problem is corrosion of studs themselves- internally, that snaps the ends off with bolts intact.
I have a 1991 964, 186,000 miles and just found three stud ends with bolts attached in the valve covers when preparing to do a valve adjustment.

Dilavar?

Strange, possible that there is a difference between US and ROW cars on this. I have checked 4 964 engines and 1 993, they all had just steel studs.

Dan J · 10-01-2013, 10:22 AM

You must have jinxed me 2 customer cars today with broken studs 1 intake 1 exh
993 were steel

umgang · 10-02-2013, 07:07 AM

Quote:

Originally Posted by safe

Dilavar?

Strange, possible that there is a difference between US and ROW cars on this. I have checked 4 964 engines and 1 993, they all had just steel studs.

Yes, Dilavar. The problem is not like the old days where they pull out of the case.
The problem here is simply age and corrosion. They corrode and snap, in my case with the head stud bolts still in place.