Bernie

Hi All,
First, a big thanx to Greg86_5 and Wally for their continued effort in helping me narrow down my vacuum and false air leaks.
Greg, the innertube trick works great and helped me identify a couple of other trouble spots.
Wally, I bypassed the idle stabilizer and the car wouldn't run at all. I turned the idle adjustment 3/4 turn clockwise and it bottomed. Hmmm, lets go counter clockwise then. Spun it out by 3 turns and the car now idles. A little high so back in 1/2 a turn. Now it really doesn't stall anymore. Probably another PO screwup. I suspect that only having the idle screw up 3/4 of a turn from bottom means that the idle wasn't set at all. Correct me if I'm wrong? I need a good external tach to set it exactly but I am satisfied right now.
On to false air. Found cracked runner boots on drivers side and replaced them all. Passenger side left for next parts order (they're not leaking anyway.) Once fixed, I found a cracked elbow on the smog pump actuator. Need a part but PVC'd the elbow as temporary fix (it worked. Also put on o-ring around outside of MAF body and seated it properly in the intake.
I pumped up the MAF using the innertube trick and heard air leaking from the rear of the motor on the passenger side. Hard to isolate (buying stethescope this week). It appears that it could be the cam cover but I think it may be the cam seals at the rear. Is there anything else back there that could be the cause of the leak? I also have a burning oil smell when I throttle hard so something's getting pushed out somewhere. Could it be those seals as well? My sparkplug sockets fill up with oil on that side too so I am changing out all the cam cover gaskets.
Next question:
What tool works best for getting to those tight corners on the cam covers? I messed around trying to get various wrenches down there but with little success. My shark has hex head bolts not hex socket cap screws. Any suggestions would be appreciated. Finally, are there some good alternatives for vacuum lines? Once I pull the intake (soon) I plan on changing all the lines and I am wondering if I need BIG3 input for these parts or will "over the counter" vacuum lines and fittings suffice?
Once again Greg and Wally, thanx for keeping my shark from dropping dead in traffic.

Dozman

Bernie,

Where is your oil leak originating from? The reason I am asking, I recently replaced my seals and all vac lines, elbows and etc...in the dreaded 'V'. I found the PO was so generous, that he thought I would enjoy reinstalling the hose clamps back on oil lines in the 'V'. This had cut most of my oil leaks down to nothing.

John D.
'85 928 Auto, Black

Greg86andahalf

Bernie, Sounds like you're making great progress!

I haven't tried the smoke method, but there is a way to blow smoke into the MAF, then presurize and watch where the smoke comes out.

You can also try starting the car and lightly spray carb cleaner at suspected vacuum line leaks listening for a change in idle. (be real careful spraying around spark plugs and wires while car is running!)

I may be overlooking a component, but on the passenger side rear, there is vacuum at the fuel dampner, the transmission vacuum line may run down the firewall around there, there's vacuum at the hot water valve in that area, the multi-splitter below the airbox, and a few lines running under the intake. and that's about it.

I would follow the oil leak as you indicated.

As far as vacuum connectors and elbows are concerned, I found at least on some sizes, the OTC ones fit loose. I assume that the 928 stuff is metric and the OTC hose and fittings I tried were SAE.

If you call DR, he can set you up with what you need. I bought enough rigid line (not allot of line, really) to redo the car including the long run to the transmission. I tried to make my own multi-splitter with some OTC stuff I had, but as I said, the sizes were wrong and the fit was poor.

The oil leak has me interested. Keep updating please.

HTH
Greg

joel roeder

i dont know how deep your ck,s have gone so far but have you ck,d the tps at idle position. the cpu needs idle contact to want to run the idle air valve properly. also the throttle plate itself needs a certain amount of bypass air to alow for a base idle. if the butterfly bore is real dirty it upsets this bypass air and somtimes the tps. good luck, joel

Bernie

Hi Joel,
Thanx for the input.
I haven't checked but i think the tps is alright. Actually, I think the overall stall problem has been licked. Car is starting to idle much smoother as leaks start to disappear and the low speed stalling has ceased. My curiousity there lies in where the idle was set and where its set now. I mean the adjustment was only 3/4 of a turn from being completely down. It took 3 turns up to get the car idling normal. It does however idle properly and once the idles stabilizer was re-engaged, no more problems. Does 3 turns up from bottom sound normal or does that seem like a lot. I just want to be sure I am not avoiding the real problem with idle adjustment. The car idles smoothly without the help of the stabilizer so I assume all is well and that the last mechanic was too busy to do his job properly - gggrrrrr <img src="graemlins/cussing.gif" border="0" alt="[grrrrrrr]" />

Greg
I don't think these are vacuum lines. When I pressurize the system, it sounds a little bubbly so I would suspect there is fluid of some sort involved. It sounds like its coming right from the back of the motor itself and since I am leaking oil anyway, I am hopeful that it might be one and the same.
Once I am ready, I will do price shopping between the BIG3. I will take your advice. What about VW parts? Probably cheaper and probably will fit well. Hopefully cheaper then the Porsche stuff.

Any ideas on tools to fit those tight spaces on the cam covers? What about "crows foot" wrenches. I don't own any but I am wondering what tool works best to get into those tight areas?

Thanx again Greg and Joel.

Hey Doz,
No, I think all the poop up front has been solved except for the gasket on the filler neck. There is a small amount of oil in the V but I don't think it is much to worry about for now. All problems appear to be gaskets throughout the 1-4 bank. I've got new cam cover gasket sets but I want to powdercoat the covers before the reinstall. The shark is a daily driver so planning is very important. One screwup or non-finish and I'm takin' the bus.

WallyP

The most common oil leaks at the rear of a four-cam engine are the cam bore seals. If you look at the front of the cylinder heads, you will see that the cams and sprockets occupy the outer cam bores, and that there are plugs in the inner cam bores. On the back of the heads, there are four of the cam bore plugs.

The '86 originally had metal plugs with O-rings. The O-rings get hard and then leak. The O-rings are NLA, but you might can find the proper size locally. Porsche now supplies rubber-coated cam bore plugs that do a very good job of fixing the leaks.

Replacing the plugs on the rear of the engine is a real PITA, but it can be done. You will have to use some interesting tools to pry and push the plugs into place.

The idle adjustment sounds as if someone had cut the idle air bypass way down in order to compensate for leaks. Now that you have fixed soem leaks, you have to open up the bypass to get engough idle air.

Bernie

Hi Wally,

What your saying about the idle makes a lot of sense. You know what bugs me? Looking at the amount of money the 2 PO's paid out for "top notch" service!!! I mean, between the two of them, they paid out nearly the price of the car in repairs. When I see some of the band aid crap that's been done to this car, it makes me ill.
I'm on a mission now!!!

The cam bore plugs sound like they may be the culprit. Is this something that could have been another botch repair? What I mean is "what service being done to the motor would require removing these cam bore plugs?
The bigger PITA is the stink of buring oil everytime I jam the pedal.

Do any "special tools" come to mind for this repair? I guess I should be tackling this job when I go in for the cam cover gaskets - or does it make a difference.

I think the stalling problem is finally coming to an end and I need the Rennlist members to know that you were all responsible for the fix.
I am very grateful.

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

WallyP

Leaking cam bore plugs wouldn't be a botched repair - just old O-rings.

No special tools available to replace the plugs, but you will need to use some ingenuity.