Symptons of possible broken head studs
 

Just started to make a strange noise under a load, almost sounds like a air leak but goes away with higher rpm's. I had a valve adjust done back in March and the wrench found a broken head stud in the valve cover. He said it would be ok for awhile because it was one in the middle but with one breaking there will be more to follow.
Could this be one of the symptons? and what other things will the motor do?
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1981SC Coupe

Thanks
Barclay

Please, Just take it to a competent mechanic and have it fixed

Broken head studs
 

The cylinder with a broken head stud can sound like it has an exhaust leak at the header flange when idling but it is actually the power stroke expansion gas coming out of the head gasket or base seal. I have this problem right now, top end rebuild coming this winter.

I don't know about 911s, but I have seen that kind of leak destroy heads on 914s. Think red hot flames on aluminum.

Sounds like a broken head stud(s) to me. That's what mine sounded like...

sometimes you can drive with the broken stud if it hasnt started to leak yet but it seems too late in your case.
the diesel sounding exhaust leak is ruining your cylinder and head mating surfaces.
Ask how I know....

Unfortunately it sounds like yours needs to be fixed now. I wouldn't drive it anymore in hopes you can salvage the head and/or cylinder with the broken stud.

im no expert but in the past, ive searched this topic and i recall reading that if the sound goes away when warmed up, you may have an exhaust leak which is disappearing once the heat expands the metals and temporarily closes up the leak. I mention this because you said it goes away at higher RPMs which suggests to me, perhaps, that its actually going away at higher temperatures.

However, you do now know you have a broken stud. if the guys on this board are warning you, why didnt your wrench warn you of the dangers suggested above? what kind of wrench is this person?

btw, there are suggestions around, including I think, Wayne's book, that say a broken stud in the middle is not as bad as one of the outside studs.

Yes,..the "pieces' to be found from broken head studs (as they will certainly be evident, no?)

I know the guys' have suggested some Extension of longevity as to ignoring these types of failures////I wonder,,..,..but will go with the pros,..and that it needs addressing,..no?

Not sure,..but most welcome for data...


Best,

Doyle

It sounds like playing cards in the spokes of your bicycle....that and the nuts in your valve covers....are prime indicaters....

Agree with everything said here. Before I knew I had broken head studs I noticed a rattleing noise under acceleration until the car warmed up. Once it warmed up I didn't notice anything strange, maybe down in power a bit looking back.

Once I found out I had broken studs the car was never started again until repairs were made. I had 4 studs from different cylinders fall into the oil pan when I went to do an oil change and I still have nightmares about that night.


I'd question a mechanic who thinks it's OK to drive a car with broken head studs, the fix is fairly cheap right now but if one of the other three lets loose hang on to you hat.

Good luck

Brian

Thanks for the responses, This started two days ago. Back in March when I had the valve adjustment there was one no issues with this leaking sound that I'm getting now. I will not be driving it much anymore.
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1981SC Coupe

The mechanic I use is very good and would not stear me wrong. If he says it's ok to drive it and not be to aggressive with it then I believe him.

Mind you it was only one stud in the middle.


Thanks again for the responses
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1981SC Coupe

When you do decide to get your head studs replaced, I'd recommend a set of these...

http://i81.photobucket.com/albums/j2...1/DSCN1684.jpg

ARP 911 stud kit. Pretty much bulletproof. Around $650.

Take Bill's advice or park it. Here is the 2.7 Daughter Project engine I am working on now. Pulled studs. Note the head is beat to death and beyond repair because the remaining studs would not hold it down. Also the cylinder is beat to death and beyond repair. Once one goes, it increases the load on the others and combustion pressure starts blowing by destroying things as you go.

If this engine had been repaired sooner, the costs of the rebuild would be much less. Drive it if you must but IMHO you are making a huge mistake
http://forums.pelicanparts.com/uploa...1220674418.jpg

http://forums.pelicanparts.com/uploa...1220674456.jpg

Henry @ Supertec sells a nice set too, available thru Pelican.

Lots of mechanics say stupid things....

what is the typical cost of doing a head stud job? certainly a job that all SC owners should plan for.

+1

That's bad advice from your wrench. "OK to drive just don't be aggressive" is true before the cylinder leaks. You are ruining very expensive parts by running a leaky cylinder.
The pics 84toy posted above would be even worse on an SC because of the spring loaded head gasket that scores the head and cylinder when the leaking cylinder blows it out.

This post was started to tell all that I'm hearing what I think might be another stud or studs giving way. Back in March there was no leak with one middle stud out.

I have stopped driving it and will price out the cost of a re-build.

Thank you for your concern

Barclay

3-4K....depending on what's needed and the "while yer in there" stuff that piles up. DON'T put the same crappy studs back in....buy new Raceware....