'79 Turbo Head Stud Problems

[Germaneighter]

I posted some time back about a troublesome noise on a '79 Turbo with about 65K miles. When the turbo starts to kick in there is a knocking noise....sounds like a loose exhaust pipe banging against the frame. Many people suggested a broken head stud. One person suggested it was the bypass gaskets. I changed the gaskets although the existing ones were fine.....no difference. Well I finally got around to pulling the lower valve covers as many suggested, the right bank had one broken stud. I did not check torque on the others as it is late and I am shot....

At this time I need some advise.....a friend of mine bought this car a couple years ago. He drove it only twice then parked it. (His appetite for Hemis overpowered his desire to own a Turbo.) He offered the car to me for what he gave..$22,500.00. I thought it was a little steep but he told me to put $5K down and take the car. Payoff could be at my leisure within two years. This was probably the only way I was going to own a Turbo in th near future. I called him immediately after getting it home and informed him of the noise. He had not heard it during his two trips.

Now for the advise....Should I re-negotiate with my buddy or run? He is OK with whatever I decide. If I re-negotiate, how much could this cost me? How far should I go on this repair? I will likely do the work myself if at all possible. I have owned four other 911s but never a Turbo. The rest of the car is in pretty good shape except for paint. It is petrol blue and has been re-sprayed...not a great job either.

Any thoughts?

Germaneighter
'79 SC Targa
'73 914
'79 Turbo Coupe (Maybe)

[beepbeep]

It's not so problematic, albeit pretty unusual to see broken stud on turbo ... you can probably do it yourself. Try to bring down the price a bit so you can afford parts. You never mentioned mileage, but you could also do some valve-job while everything is off.

As i said, Turbos rarely break studs but often start to leak from head/cylinder gaskets (probably beacuse heat-induced expansion coupled with boost trying to lift the heads etc.) so it's good to take off those parts and resurface them now and then.

It's a cool car and you'll probably like it more if you fix this yourself. That being said, it's a bit steeper than plain-vanilla SC so if you have "afordability-problems" then you got wrong car


Cheers!

[yelcab1]

SHould have thought about carefully when you buy a car from a buddy. I say stay with the price, just make sure he pays for the repairs. Have a shop do it so they can find out if there is anything else wrong.

[john walker's workshop]

turbos have 24 dilivar head studs. it's common to have one break, turbo, or normal engine. they all need to be replaced when you tear it down. the heads may need to be flycut to repair the surface that contacts the cylinders. one bad surface means a flycut on all. a valve grind would be prudent at this time, as well as rings. the parts will be in the $1000 range if you do it yourself. easy to get carried away though, "while it's apart". the purchase price seems reasonable, in spite of the problem, but if your friend drops the price, so much the better.

[Doug Zielke]

Turbo's (930) have *all* 24 head studs made from the infamous Dilavar alloy. They get corroded/fatigued and start to break.
The prudent thing to do is to do a top-end inspection, and replace all the studs. That, and a re-seal. The costs can escalate from there if you're unlucky.

Edit:
Sorry JW......I type and think way too slowly.

[beepbeep]

OK, guru has talked

I stand corrected on failing 930 studs. Somehow, i didn't heard about it nearly as much as on SC's. Maybe beacuse there are fewer 930's?

P.S. Shouldn't low CR in 930 engines make life easier for studs when off-boost?

[TurboBert]

For what its worth, I think you got a good buy on the car, even with a broken stud. If your friend is willing to lower the price further to offset the repair, then that's a steal. Friends like that are hard to find.