SC non snapped head bolts roll call

[Clark Griswold]

Greetings. Hope I am not blowing it with a noob first post, but this is something I am curious about.

I have no problems finding horror stories of snapped head bolts, but I am curious of the opposite.

I recently bought a 1980 SC with 56k miles (give or take because VDO. I have learned enough in the BMW world to know to take mileage with a grain of salt) But this car has only been driven 900 miles since 2007 (when PO passed away. RIP).

I got someone that knows air cooleds better than I to give it a once over, replaced all fluids and some belts, then proceeded to push this car for over 100 miles of non stop tight turns today. 92 degrees. No AC. I feel beat up but the car is a damn mechanical marvel. Blown away at it's performance.

I want to dump some money into the suspension and get the wheels RSR finished.

Are head bolt issues a 'not if, when' issue like I have read? Are there tons of SC 3.0 owners who have had zero problems? I am trying to get a feel for this issue since it's irresponsible to spend money on fun stuff if head bolts are an inevitability. From my research I read that lower mileage cars are more prone? Couldn't find any real evidence to back that up though.

[Clark Griswold]

[gshiwota]

Greetings and welcome! Congrats on your new (to you) 911 and it's great to hear that you're driving it like it was meant to be.

I've had 5 911s (3.0 and 3.2) over the past 10 years. Unfortunately all of them had broken headstud issues. My first 911 sound similar to your as it was a low mile '82 46K mile car that was sitting for a few years before I bought it. It had a PPI that checked out but after driving it for a few thousand miles it developed a broken headstud.

The next 3 cars I bought, I made sure that they had headstuds replaced / motors rebuilt - the prior owners had problems but not me.

With my current 911 I thought I was smarter... I bought a used 3.0 motor that had a top end rebuild for my '75 (2.7). I had the motor PPI'd where they checked the headstuds and they were fine. The motor sat on a pallet in my garage for a couple of years waiting to go into my project 2.7 and one day when I was moving the motor, a headnut fell onto the ground. I reviewed the paperwork on the rebuild and saw that the shop replaced the headstuds with new Dilivar headstuds and it's the new Dilivar studs that are breaking. I found 2 broken studs and they only had a few thousand miles on them. I'm now learning how to rebuild my own 911 motor and am in the middle of replacing headstuds on my 3.0.

My experience is not scientific and I don't want to scare you and make you think this is a guarantee that you'll have problems. I may just be one of the least lucky guys in the world when it comes to broken headstuds. However in my experience, be sure to budget for it especially since your motor is lower mileage and/or had been sitting for a while. If you do have problems know that it's not the end of the world as it's a great excuse to make the motor stronger and/or learn how to wrench on these things. It's really not that hard especially with all of the great support on this site.

[rwest]

Welcome, good looking car, does it have a Pasha cloth interior?

[fanaudical]

Welcome to the forums. I have found tons of help and support here. Nice looking car.

I don't have any data for you on your question. I guess I just have a follow-up question:

Would you still have bought the car if you were expecting engine trouble?

[howard freeman]

Welcome to the Porsche world. The short answer is they will break at some point. It will be a bottom row stud. Those are the dilivar ones on that engine.

[Clark Griswold]

yea it has Pasha.

This kind of blows. Not the answers I was hoping for. I don't see me having the time or talent to tackle it myself which means $$$$.


Am I also correct that there are no symptoms for this issue?

[Mark Salvetti]

There was a poll on Rennlist a couple of months ago. Of 24 respondents, 17 had broken a stud.

It seems to be a matter of when, not if.

Eventually you'll hear an exhaust leak. If you find a broken stud when adjusting valves, you don't have to park it right away. Finish the driving season, fix it over the winter.

If you hear the exhaust leak first, I think I would park it before the leak damages a sealing surface.

Mark

[pmax]

It’s caused by corrosion.

Garage queens and winter drivers are more prone to this problem.

[Clark Griswold]

Any difference on a RoW car vs US as far as head bolts?

[Clark Griswold]

garage queens are more prone to corrosion?

[Bill Douglas]

Oh Jeesus, nice car. And nice girl in there too.

Welcome to Pelican Parts. Don't worry about problems well before they happen. Keep on enjoying that excellent car

[Clark Griswold]

Originally Posted by Bill Douglas

Welcome to Pelican Parts. Don't worry about problems well before they happen. Keep on enjoying that excellent car

This just summed up most of my problems in life. something something be present / stay in the moment.

[smadsen]

I've had my '82 for 15 years. The clock shows 241,000+ miles. I got it at 157,000 miles. To my knowledge the motor has never been opened. It still has a nice linear pull to 6000 RPM. I've fixed most of the common leaks, replaced the clutch, and adjusted the valves every two years and checked the studs/nuts. Car has always been garaged and of course in so. Cal the streets are seldom wet. Some day I'd like to do the motor, out of curiosity if nothing else, but if it ain't broke...…….

[Coastr]

Mine has not. 95k on three prior owners. But then sometimes cars get repaired and the receipt is not put in the folder.

Nobody seems to know for sure. Garage queens seem to corrode more because more time for moisture to build up and corrode. Regular drivers heat off moisture.

Don’t worry if the studs don’t get you the tensioners will.

FWIW I have known cars with no engine issues at all. It’s like IMS issues- you hear about the bad outcomes. Most people have no idea if their SC has ever had broken studs because few cars are one owner/one famiky

[manbridge 74]

1) Don’t worry about it. Rather keep an eye out during valve adjustments.

2) Nice car, need some interior and engine pics.

3) Nice screen name

[Clark Griswold]

yes! some positive comments!!!!

I mean even my title is attracting people that have had head stud issues.

It's always tough on the forums. These are the places where people diagnose and fix the issues so it is logical that the issues get the focus. Nobody, well I shouldn't say nobody. but most people don't come on car forums and say hey just wanted to check in, zero issues, cheers!

[Reiver]

I have an '83 and traded my 930-16 (your same motor) for a euro model. When I swapped it out I had 230k miles on it with the original head studs 5 years ago...it ran well but was tired.

Generally, it is the lower mileage cars that have the issues as many were driven on short drives and not properly warmed up...if the studs had any imperfections (surface nicks etc) then the condensation would attack the areas open to corrosion. That explanation is not from my experience but from talking to Porsche mechanics.

I suspect location is an issue too....colder climates and exposure to road salt some say.

The car/motor that I have has always been in the Phx. Az. area or Socal….hot and dry.

The '83 Euro I traded for had a top end rebuild 6 years ago at 67k miles due to 3 broken studs (dilivar) and the conditions I described above...short drives not to temp. It was rebuilt with all steel studs.

If it is good to go then just drive it....get it up to temp and have at it....the more they are driven the better they 'act'...

BTW...if it was driven properly you may just be fine...anyways, with that mileage you wouldn't need a case opening just the head and a minor top end job (not cheap but the lowest engine work monetarily)

Nice looking SC...I like the gray's and have Pascha in mine...just the seats tho.

[Clark Griswold]

my car pretty much ticks all the boxes stated for broken head stud candidate. Low mileage. Garage queen. Northern car (Chicago and Wisconsin). Car is amazingly rust free and supposedly never driven in winter and kept in climate controlled garage. This info came from seller and I take it all with a grain of salt.

It's a Germany import.

I guess my thing is I am all for enjoying the car until the problem arises. Just not sure when that is exactly since head bolts apparently show no symptoms.

I suppose I will do as the gentlemen suggests and check them whenever valves get adjusted. Last one was done in 2013. edit: 2013 and probably 500 miles ago. The thing sat a lot.

[hienz]

My 1975 911s has 35K, and garage queen for years. It never has any major problem until this year 2018 while checking for valves clearance, I found one head bolt fail off the head stud. I put it back and still running strong as new.