[Cloud9...68]

Wow, that's a strange one. I can't think of anything in the variocam chain pad replacement procedure that would cause massive oil consumption without also causing the car to run horribly, belch black smoke, etc. That is excessively high oil consumption. I changed my oil over 1000 miles ago, and the car is almost exclusively a track car (other than the drive to and from the track), and the level on the dip stick hasn't gone down a millimeter. Are you sure it wasn't consuming a lot of oil prior to the pad change?

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[fleetwood]

Yeah -- before, it was a qt, maybe a 1.5qts, in between 3000 mi oil changes.

Definitely started after the variocam job -- could be coincidence, or maybe they unsettled something when taking apart/putting back together..?



Air/Oil Separator leak or other vacuum leak causing oil to be sucked into intake?

But then there's no smoke out the back...

Coolant is clean, as well..



Runs great -- just eats oil like crazy, and cant figure out where it's coming from or where it's going

Aside form the cost/grief of constantly adding oil, imagine this will kill the cat sooner than later too...

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[flash]

when they set the cams, they may have set the timing wrong, which would change the overlap.



the variocam solenoid itself could be leaking the oil back into the valve cover and down into the valves.



then, as mentioned, there is the AOS.

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[fleetwood]

Schiza --- gonna check for vacuum leaks first.



How much of a pain in the arse is it to replace the AOS?

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[Cloud9...68]

But wouldn't any of these effects (wrong overlap, faulty AOS, variocam solenoid leak) creating an oil leak into the engine cause it to smoke like a chimney?

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[flash]

not necessarily. depends on the rate and if it's vaporized. also, you usually can't see the smoke if you are driving. it takes someone behind you to see it. ask me how i know.



can we presume that it's not leaking out the corner of the valve cover? if they didn't put shmutz in the corners, or reused the gasket, you could have a leak there.

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[fleetwood]

Yep - no leaks anywhere (have triple checked from top, bottom, w/ mirrors)



I've had the wife follow on the road, and I've stood behind it at home while someone else revs & holds the throttle -- no smoke

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[fleetwood]

have also replaced oil fill cap and dip stick o-ring (saw a separate post here where that was the source of a vacuum leak / oil consumption problem).



If there were a vacuum leak at the top of the AOS, would that cause oil vapor to be shot into the intake?

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[flash]

it's a bit of a question just how that system works, but if there is a vacuum leak there, it will consume oil.



no smoke is good. that means that it is a more gradual process, and not likely a ring issue. basically you are combusting the oil, and it's not shooting out the tailpipe unburnt.



could be a valve guide issue though.



after searching for vacuum leaks, i would do a leakdown test to rule out any engine issues. to search for vacuum leaks, you will need to pressurize the system and use a gauge. you won't see small leaks any other way, though a gauge by itself would indicate any large ones. you should have a solid and unwavering 17 inches of vacuum at idle.

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[fleetwood]

Thanks much, Gentlemens - as always

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[Scott Collins]

Fleetwood,



Careful with the AOS - particularly the connection on top to the vacuum hose. There is a rubber elbow that connects the vacuum hose to the top of the AOS. The rubber elbow will likely have a crack in it, leaking air. You will want to pull that off, but BE CAREFUL!



The plastic can become brittle, and when you twist the elbow, if it is frozen in place it may crack the connector sticking out of the top of the AOS. I know from experience and it was time-consuming and costly repair. I'm not even sure that a new AOS can be optained, and the part is different from the 944 and 944 turbo cars. To compound the problem, the AOs is in a spot that is very difficult to get to.



Max at Provost Morotsports in Bordentown, NJ, did a repair which involved sealing the crack with some sort of sealing compound.



Take your time with that and good luck.

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[fleetwood]

Will do, and thanks for the heads up Scott -- much appreciated



yeah -- pelican lists AOS as a special order part for $600+ -- trying not to go that route...

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[KRAG50]

One other thing to note with the AOL, the whole top snaps on to the body and is sealed with a large O ring, that O ring degrades and can cause a perimeter leak over and above the hose attachment points. If you try to remove the top the snap catches will likely crack and it will be hard to get a reseal. This is how I found my vacuum leak. I ended up purchasing a new one, from Sunset, a bit over $400. You might be able to seal it with a Urethane automotive fuel proof sealer and not disassemble. I purchased a new one because I'm boosted and the AOL sees boost pressure, I didn't feel it would hold up with just an external sealant.

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[fleetwood]

Thanks for this --

I dont know yet if that's the source (or the only source) of the crazy oil consumption going on right now, but on inspection, the AOS does have a film of grime and oil on top of it.

I've cleaned it all off, and am watching to see if it returns (to see if this is an active leak, or if the oily grime was 20yr old residue).

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[Cloud9...68]

Post deleted.

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[jferraro17]

Pads.....



My service provider is telling me he can't find the lower pad without buying a complete tensioner from his parts sources. Can any of you who have replaced you pads tell me where you bought them? Did you replace the tensioner as well?



(Quick answer appreciated, the engine is open right now)



Thanks!

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[vliegwielolaf1234]

Top and bottom pad are the same .

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[jferraro17]

Great! Thanks!

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[MLB]

PN 944 105 509 00

About 18 apiece from sunset last year

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[jferraro17]

Just got home. Got a good look at the open engine...I'm not sure the pads even need to be replaced; although I couldn't see the bottom one, the top showed almost no wear at all.



The tensioner is really extended, so the chain is being replaced. Pads will get a second look before a decision is made. Just glad I don't have to buy a tensioner just for the pad!



Decided to change the timing belt, but keep the water pump, and bearings. Cam shafts looked great.



Getting this thing up to standards is worse than building a house!! <img src="/forum/images/smilies/968/dry.png" class="smilie" alt="" />



Thanks again for the help.

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