Judgement day for my engine.

jk911 · 08-31-2003, 03:16 PM

After having owned the car for nearly 2 years and having always supected that my engine had pulled head studs. I finally allocated Saturday as the "judgement day" at which time I would adjust my valves and check out the head stud stiuation ....

So here is the result :

1) first time I have ever performed a valve adjustment...... It was so easy I couldn't believe it BUT I also couldn't believe how LONG it took me to do " The Whole day" ! (all my valves were pretty tight. I fact I think most were too tight )

2) All my head studs were intact !

3) I re- torqued all the head studs at 24 lb/ft. None were loose but a few tightened slightly more . They were all stong and tight in the end !

I was so happy to find this because my mechanic told me that he thought I had a couple of pulled studs (without taking the valve covers off ..mind you) so i believed him and thought this all along.

Can someone plaese confirm that I don't have any pulled head studs given my results on saturday ? Note my car is a fully original early 1975 cis (1974 type with none of the pollution things and the 11 blade updated fan) It also has only travelled 43,000 miles.

Am I as lucky as I think ? or not ?

The reason I suspected pulled studs is that when I drive past a wall I can hear a phatt... phatt.. phatt sound. I must also note that my exhaust is 28 years old and has a few small rust holes in the silencer part ?

What do you guys think ?

dd74 · 08-31-2003, 03:54 PM

I can confirm the holes in your exhaust is the reason for the "phat" sound. Early on when I had a 2.7, I also had an exhaust with holes in it. When I replaced it the sound was gone.

Good work on your valve job!

jk911 · 08-31-2003, 05:13 PM

Thanks for those words of comfort "dd74".

I basically want to know the way to test for pulled head studs.

Is resistance at 24 lb/ft a clear sign that the studs are not pulled ?

350HP930 · 08-31-2003, 05:52 PM

I would say that the fact that they all successfully torqued and none required more than 'slight' additional torquing is a good sign.

Then again some additional twist and torque and few additional miles might be all it takes for one to have incentive to give up the ghost.

I used to hear so many horror stories about old turbos that I was certain my engine was going to be some kind of basket case when I took it apart.

I was pleased to have only one stud that broke in the middle after 130K miles after a lot of hard use and due to daily driving a lot of wide temperature ranges too.

Doug E · 08-31-2003, 07:28 PM

Congrats on not finding any broken studs. When I went to do a recent valve adjustment I found 3 busted studs on mind

The only way I've heard to check for a pulled stud is either via sight (once it is torn down) or a measurement but I don't think either of those are possible with the engine in the car.

Adam · Adam's Garage

Another good way to check is to look for weepage where the cylinder barrels meet the crankcase. If your studs are pulled or pulling, there would most likely be some evidence of it there.

Do a compression test too. It's also a good indicator to see if your valves are consistently set.

jk911 · 08-31-2003, 08:15 PM

Another thing I noticed was my right flat panel of the heat exchanger was rusted with a big opening (hole) near the mufler . will this cause any problems other than bad heat contol. I.e will this cause excessive engine noise or any tother problem ?

911pcars · 10:38 PM

350HP930 wrote:
"I was pleased to have only one stud that broke in the middle after 130K miles........."

Just curious. Do you recall what row this stud break occured and the color of the stud (silver, gold or black)?

Thanks,
Sherwood Lee
http://members.rennlist.org/911pcars

k9handler · 08-31-2003, 11:11 PM

the exhaust leak would cause the sound you described, as well this can be from a damaged exhaust gasket...sounds like you are in good shape with the engine though.

jk911 · 08-31-2003, 11:20 PM

Sorry for the dumb question ... But when you say exhaust leak do you mean the muffler at the back or the heat exchangers ?

k9handler · 08-31-2003, 11:33 PM

I mean at the heat exchangers, I had a exhaust head gasket blow out on mine on the way to ship the car from LA...and the sound you describe was it to a "T".

jk911 · 08-31-2003, 11:45 PM

Thanks K9 . Ill check it out !

350HP930 · 09-01-2003, 07:11 AM

Quote:

Originally posted by 911pcars
350HP930 wrote:
"I was pleased to have only one stud that broke in the middle after 130K miles........."

Just curious. Do you recall what row this stud break occured and the color of the stud (silver, gold or black)?

It was #4 (right front) and it was black. I was an exhaust side stud that broke in the head area so you could not easily tell it was broken and I am pretty sure it was the stud that was not next to the oil cooler.

A couple of other things that stud had going against it was that the right side heat exchanger was probably a lot hotter than normal since my right air shroud air feed nozzle was broken and it was the furthest cylinder from the knock sensor.

Doug Zielke · 09-01-2003, 07:52 AM

Once again, it seems there is some confusion here between a pulled stud and a broken stud. Pulled studs (case thread failure) occur in the later mag-case engines (jk911's for example). Broken studs are usually attributed the Dilivar stud type as used on 3.0, 3.3 and 3.2 motors.
It's a bigger deal to re & re a mag case with time serts, than a Al case that just needs some new (steel) studs.

jk911 · 09-01-2003, 07:38 PM

Correct.

Another question ..

If the engine has pulled studs wouldn't the nuts be really loose in every case. ???

UTKarmann_Ghia · 09-01-2003, 08:09 PM

Here's a stoopid question: If you didnt do anything about a broken head stud or two, what could happen?

jk911 · 09-07-2003, 03:10 PM

Update,

On the weekend I put my hand onder the engine while it was running and I could feel air blowing out under the heat exchangers around cylenders 2 and 6.

I obviously have major exaust leak problems (my car is so load !) but I can't tell if its comming from the heads, the gakets or the heat exchangers.

Any suggestions ? how can you diagnose the cause ?

350HP930 · 09-07-2003, 03:16 PM

Pay $ to fix it right, right now, or pay $$$ to fix more stuff down the road.

The choice is yours.

dd74 · 09-07-2003, 03:30 PM

I had a minor exhaust leak once with my SSIs. I took it TRE, and Tyson wound up putting double gaskets between the outlets and the SSIs. This might be helpful. It certainly fixed the leak for me.

But heed the advice to get this fixed soon. If you burn an exhaust valve, you'll be very sorry.

afterburn 549 · 09-07-2003, 07:58 PM

to properly retorq. you have to back the nut or bolt off a 1/2 a turn or so.
this gives a much more corect reading. sa far as yours goes... drive till the next valve adj. then retorq this way... but i would sneek it up to about 28 lbs.. I know mine were holding @ 30lbs b4 case savors.
if you did not have reactors on there chances are good your not pulin them. t.m.o.