Strange sound after valve cover replacement

[greensc]

I just did the following:

- Removed all valve covers
- Tightened one loose head stud nut on #6
- Removed broken part of head stud on #6
- Replaced all valve covers with new gaskets (I tightened the cover nuts too tight first, then realized it and retorque to 6ft-lbs)
- Replaced chain tensioner oil lines.
- Removed oil strainer and replaced gaskets
- New Oil filter

I refilled the car with 10 qts oil, started it up, and after about 15 seconds a squealing started. I turned the car off, added 2 more qts oil. Started it back up but the squeal continued. It didn't seem to be coming from the alternator belt, but from underneath the car.

Can anyone tell what I might have done wrong?

[greensc]

No one has any ideas?

[Wil Ferch]

For one thing you added too much oil....

Total system capacity for cars with front oil coolers is 13 qts...but 3 qts stays behind...refill capacity is typically 10 qts max...and you "ease" into this value by adding maybe 8 and topping off slowly as required...drill is car running at idle ( 880 rpm)..on a FLAT surface...and up to temp ( say 190 degF). If any one of these is incorrect..then oil level procedure won't work right.

Can't offer comment on removing broken head stud piece and/or tightening head stud...but this changes things. People who've added hydraulic chain tensioners also state that engine sounds different afterwards.


--Wil Ferch

[greensc]

Thanks Wil,

I'll drain the oil and start again. I started with 8qts, then 10qts, then I goofed and put 12qts in. (No wonder I keep finding oil in my airbox! I'm such an idiot.) The noise happened even at 8 qts.

The chain tensioner upgrade was already on the car. I just replaced leaking flexible oil lines.

This noise is really loud! It sounds like a squealing belt, but it's not coming from the belt. I don't think it changes pitch with rpm change. The normal engine noise just drowns it out.

I started it up very briefly again this morning. The noise was still there, but then after a few seconds it disappeared for 10 seconds, and then reappeared again.

The rear of the car is still up on jack stands... but I wouldn't think that could cause any trouble.

The only other thing that I fixed was the right intake valve cover had no gasket (from the last valve adjustment done by a dealer who shall remain nameless at this time). It had been run for 1 1/2 years that way.

Could re-torquing the loose head stud nut on the #6 cylinder with the broken head have moved something that is now scraping.
Thanks for any suggestions, or criticisms!

[scottb]

This is an odd one. You might try posting something on the engine rebuilding board. Maybe they have suggestions. Good luck!

[Jim Sims]

Some ideas:

Blockage (perhaps partial) in a new camtower oil line that is limiting oil flow to cams. Was any silicone rubber or RTV sealant used in your engine?

On number six, did you tighten a cylinder stud nut or a camtower to head stud nut? If the later, you may have put the camshaft into a bind.

What type of oil filter did you use?

Was the sump screen and cover plate reinstalled in the proper orientation? If not, the oil pump pickup tube may be pushed upward putting the oil pump in a bind.

Good luck, Jim

[Gunter]

Re-check the position of the sump strainer plate and screen. It has to be mounted so that the pick-up pipe sits in the plate recess. (Essential for suction) Also, put the car level before running so you can tell the proper oil level. What is this:
"Removed broken part of #6 head stud"? Are you saying that there is a broken head stud? How many?

[AirCooledExcellence]

John,

You said that one of the valve covers didn't have a gasket? If so I reckon it must have been tourqued down really tight to stop the oil leaking out, perhaps the cover has been warped and now you've put a gasket on (and torqued to the correct value?) is now not sealing properly?

Cheers

[jason2guy]

im gonna second the sump. recheck that thing pronto

[greensc]

Will do tonight. Thanks for all the great advice guys. I was feeling pretty worthless last night after two days of work and ending up with a bigger problem than was I started with.

(BTW: I come from the midwest where guys is guys and gals. I should just say y'all)

[greensc]

Tim:

Yes, I think it was torqued down tight. But oil was still leaking out a little. This was a Porsche Dealership that did the work.


I was stupid and overtorqued all the valve cover nuts the first time I put them back on. I should probably check all my covers for warping.

I'll look for a thread on flattening them back out. I have the turbo covers.

[smarjoram]

my heater blower fan makes a deafening squeal, and it's intermittent - you sure it's coming from underneath?

[Early_S_Man]

John,

If the sump cover was installed without the proper clearance around the oil suction pipe ... the scavenge pump may have been sucking air because of the blockage ... and, the sump may have completely filled up with oil! How long did you run the engine both times? Did a proper oil pressure reading ever take a nosedive during test running?

[RoninLB]

Originally posted by greensc

(BTW: I come from the midwest where guys is guys and gals. I should just say y'all)

y'all live in an old famous party town.. I had some wild party action in Boulder just before they had traffic lights.. the cops couldn't keep with the street action.. that's one of the reasons for traffic lights, many moons ago

[greensc]

I did find a broken head stud (bottom-forward on #6), laying in the stud recess with the nut off!!! (I don't think the nut could have come off all by itself. Hm... Did someone put it back in there?)

Only one broken on #6. But the top-forwared stud on #6 was not up to the 24ft-lb spec, so I retightened it. I can't afford to rebuild the engine now.

I'm using a mahle oil filter, brand new, same as I always use.

If the oil pump is being starved, would it make a whining/squealing noise?

BTW, this saga sort of follows after by previous thread Popping when on the gas under load .

Jim: Is the cam-tower to head stud nut one of the six 13mm regular hex nut on each side on the bottom?

[greensc]

Originally posted by Early_S_Man
John,

If the sump cover was installed without the proper clearance around the oil suction pipe ... the scavenge pump may have been sucking air because of the blockage ... and, the sump may have completely filled up with oil! How long did you run the engine both times? Did a proper oil pressure reading ever take a nosedive during test running?

30 seconds. 15 seconds. 1 minute. 2 minutes. (approx)

If I did install it wrong, can I correct the problem by draining oil, and just installing correctly? Or do I need to do something else.

I don't really understand exactly how the oil system works yet.

[greensc]

I'm sure it's not the heater blower fan. It's off.

[Jim Sims]

Don't feel too bad; overfilling 911 oil is a very common novice error. Also, in the words of my Porsche mentor : "I might as well make the mistakes since the professional mechanics seem to be making the same mistakes at greater cost," recalling an episode where professionally installed 911 timing chains were rubbing against the chain housing. Keep at it. Buy references, go slowly, search the archives on this site and ask questions (post them here) if you don't know about something. Develop an understanding of how the 911 systems work. A question is not dumb if you don't know the answer and can't figure out the answer. Cheers, Jim

[Jdub]

Where the heck did that broken stud nut go? And you might consider an upgrade to the "bowler" style of sump screen. In the '78 (i own one) the screen for oil pickup had no capacity for "retaining" the oil in the center of the sump on hard curves (or, for cars at a tilt, such as your car on jackstands I might add). In this scenario, the oil was not picked up as all the oil took flight to a side of the sump by side-G force and deprived the oil pump of oil.

But I sure do wonder where that nut went.

John

[Jim Sims]

The cam tower to head studs are fastened by both regular hex nuts and a few barrel or cylinder type nuts (inside wrenching hex). Jim