ZAMIRZ

Hey guys, took the 911 in for a valve adjustment and to fix an oil leak I had that was sourced to the oil pressure guage sending unit (located at the base of the engine fan on the right side). Anyway, went to pick the car up and he said that the head stud on the closest cylinder to the rear on the left bank has a pulled head stud. So I was like "oh, well, what's that gonna run me", he said "$4500 if you want me to replace all of them with high-performance updated units"....needless to say my jaw dropped to the floor. As a senior in High School I do not have that kind of money to blow on my car, my job only supports my weekend In'N Out hamburger binges, movies and some CDs.....the rest either goes into savings or the 911. Anyway, I took the car home with me and parked it, pulled the cover on it and am now driving my beater car until I find a solution. My friend who has a Carrera 3.2 offered to help me drop the motor and said it wasn't that big of a task, he had no idea on what was involved with replacing the head studs. So earlier today I'm looking through Excellence and I noticed that Vertex's add says "Dilavar Head Studs $12", I nearly fell out of my seat and my Physics teacher gave me an odd look. Where the hell did this $4500 price quote come from? Is it really ~$4,000 in labor? What I'd like you guys to tell me is what are my options? I have HIGHLY considered doing the work myself, unfortunately I do not have access to a lift, only your basic garage tools (floor jack, good set of metric wrenches). What all is involved with this process, and is it possible for the average mechanically inclined person to perform this work? All opinions (good and bad, if you want to slander me I'll try to take it as constructive criticism) are welcome. Thanks guy.

later,

amir

J richard

Zamirz

The $4500 is probably to tear the motor down and replacing (probably all) the studs with inserts and reassembling the whole thing. When a stud is "pulled" it literally strips the threads right out of the case, the only trusted fix is a threaded insert called a "time-cert", although I do know of a guy that used a helicoil on an SC case that seemed to take.

I didn't think that pulled studs were very common on an SC case, this is usually the earlier 2.7 problem. You might try to retorque the stud and see if it takes, you might get lucky, and you don't have anything to loose. Most mechanics won't try this unless you ask, if the stud comes out you really don't want to drive it.

If it turns in the bore or just pulls out of the case, the least costly fix is a partial teardown, insert, new stud(or studs depending what you find) and reassembly. Since it's one of the outside studs you will have to take the cam tower/heads off, and at least the jug to get the insert and new stud in. The only risk is during dissassembly/reassembly you strip out another stud. How far you go depends on $$$ and the condition of the car. Everything but the insert should be do-able with some determination, a good manual, some specific tools, a good porsche buddy and some of his favorite beer

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

hope this helps

Chris Martin

First off, best of luck with your car.

I think dropping the motor is the easy part in this job though. Depending where the stud is broken, assume the worste and be very happy if it's not too bad, you might have to pull the pisonts and cylinders to drill the stud out. This is where the "while your in there" disease can really take hold. Replace all bearings, install high compression pistions, machine heads, new cams.... Maybe you could work out a deal with your mechanic so you could do some of the grunt work? Worth a shot. The $12 stud is a replacement, the high performance studs your wrench quoted should be Raceware, the bullet proof way to go. Might be overkill for a street car, but they are the best.


Chris

Rick Lee

Well, you're in for a headache. The job can be done by you and your buddy. But probably not on a weekend. If you have 24 head studs, that's $288 just for those parts, plus shipping. I think the $4500 includes all the other things you should have done while the engine is out and apart. You would actually save money in the long run by having everything done at once. If you and your buddy can get the engine out in one day, plan on having your car apart for at least a month, assuming you can only work on it weekends. A P-car mechanic usually charges 30 hrs. of labor on a top end job. So at $65 per hour, that's $1950 right off the bat. Add his markup on parts, a bunch of other little stuff like replacing seals, valve guides, maybe even throwing in a new clutch while he's at it, and it can get to $4500 pretty quickly. If you plan to do this yourself, get all the parts and tools you'll need and have at it. You'll cut the cost in half by doing it yourself, you'll learn a ton and you'll have a great feeling of satisfaction. There's definitely enough help out there in these boards, so that you should be able to do it yourself with some persistence. Be sure and take pictures of each step and post 'em here.

Sean Hamilton

I know you said a "pulled" stud, but check the book "101 projects for your Porsche 911"- there's an interesting article on how the author dealt with a "broken" stud - in the end a bit messy, but interesting nonetheless.

jlkline

Even if you are mechanically inclined, this job is not for the faint hearted. There are a lot of subtlties that go into a teardown and repair/rebuild of an aircooled Porsche motor and you might end up worse off.

You didn't specify the engine size or mileage, but if this is a 2.7, you might want to study some of the charicteristics of this engine on this forum, and seriously consider investing in a nice used 3.0 (a bit risky). Depending on mileage and climate, this thing might be ready for a total rebuild, which if not done correctly will result in a very expensive boat anchor.

If it is an SC or Carrera motor, I'd have the top end rebuilt.... rings, valves, whatever is needed. Again, depending on mileage/climate, and if you plan to keep the car, consider the bottom end done as well, but the 3.0's and Carrera's go pretty long from the factory.

ZAMIRZ

My car is an '83 SC Euro, 3.0 liter 204hp. 100% completely stock with 97,000 miles on it.

jlkline

This motor at this mileage is a tough call for a top end. You need to look at the delta between simply replacing the studs (and all 24! The dilavars are no longer as popular than the newer 993 studs or Raceware products. I used the 993's on my 83 3.0)and getting /doing a complete top end rebuild.

The difference in parts isn't much(I'd upgrade to the hydraulic tensionsers,though)but you'll need a good P machine shop for the head work and that is the biggest difference barring any suprises.

If you choose to take this job on yourself, make damn sure you time the cams correctly, or you'll be very disappointed. <img src="graemlins/cussing.gif" border="0" alt="[grrrrrrr]" />

I would bet the bottom end is fine.

Harry

I was in the same position. I was going to do it myself(I'm very good mechanically) and lucked out by hooking up with a porsche club member that offered to help me. I never, I repeat, never could have done it myself. The engine is very basic but there is a lot of stuff that has to be done during reassembly. Don't drive your car with pulled studs, I did and screwed up a couple cylinders and the heads from them floping around.

EC83SC

Did the mechanic fix the oil leak and adjust the valves when you had it in the shop? Does it run OK? If so, I'd just continue to drive it until you figure out what you are going to do. I don't think a single broken head stud would affect driveability that much. I've corresponded with other P-car owners with broken studs who drive them daily. Your call...

jlkline

EC83SC,

I don't know which P owners you've been communicating with, but this is very bad advice.

gerry100

He wouldn't have known at all about the head stud if he didn't have the valves adjusted.

What other symptoms are there?, If none how bad can it be to run the engine?

Just curious.

Tom F

I would like to hear from someone who has actually observed damaged cylinders/cylinder heads caused by broken studs on the 3.0 or 3.2 motors. I have seen it on 2.7 motors, where nearly the whole lower row of steel studs pull out, and the cylinders and pistons show pitting and melting along the bottom part of the mating surfaces. But, I haven't seen it on 3.0 or 3.2 motors, where the stud breakage tends to be isolated. A few others whose opinions I respect say not to bother taking apart a 3.0 or 3.2 engine for broken studs.

EC83SC

I'm not trying to give advice here, just stating what I would do if I was told I had a single broken head stud. I certainly wouldn't stop driving my car unless I was hearing the telltale 'popping' sound associated with a bouncing head. There are many threads on this subject on the Pelican board and widely varying opinions just as on this board.

erkj79

I had the same problem with my 79 sc...piece of cake. Do not use dilavers they may break as well. Use Racewares. they are bullet proof. Dropping the engine is easy with some help and a simple floor jack. You can rack up a lot of miles on the sc before you see cylinder and ring wear, so I would just pull all the cylinders and replace all the studs. If you have an sc, the stud usually breaks such that you can still get a set of vice grips on it and back it out. If you need some advice email me at jmerkan@twcny.rr.com