new owner, already have a problem...

gbyron · 07-31-2009, 03:18 PM

Hello all,
I've been reading this forum for some time and it is very useful. So I finally bought an 1988 S4 automatic, and first things first started an oil change on her. Upon pulling the plug I unfortunately see some small metal shavings on the magnet, what a shame. I don't have much money in the car but still. The motor seems fine, good oil pressure, no funny noises but this is a huge alarm bell for me. here is a picture of the plug. the shavings are smaller than they appear in the picture... they are still a bit wet from when I rinsed the oil off. Any guesses as to the source? Thanks in advance

Mike B · 07-31-2009, 05:02 PM

Welcome to the club!

Hmmm, How many miles on the old gal? Have you checked for Thrust Bearing Failure (TBF)?

Have you read the VERY informative thread here?

http://forums.rennlist.com/rennforums/928-forum/40990-new-visitor-read-this-forum-guideline-faq-before-your-first-post.html

TBF is referenced in post 37. This is serious, engine killing stuff so please check it.

What colour is the residue on the plug?

gbyron · 07-31-2009, 07:40 PM

the car has 85,785 miles, it was fairly well maintained judging by the service history. there is a slight whirring noise coming from the torque tube, not screeching like I've heard in others but a sort of pleasant whirring. I figure the screeching will come next and that will be when I replace the tube. The car has 3 bar of idle oil pressure when hot and otherwise runs great. The shavings were small shards and looked a bit like bearing material

the plug otherwise just had brown slime residue from the old oil that sat in the engine 3 years in storage (I wasn't the first person who started the car so don't think I'm THAT dumb to not replace TB before even starting, but if this isn't a serious issue that is the very next thing on to-do list). I know I'll need to check for play on the crankshaft now and release flexplate pressure. If this is indeed some thrust bearing, knowing what else I've stated, what are any assumptions you may have on whether this engine is already damned just form any shavings being found or is this "acceptable" given mileage and otherwise seemingly fine condition of engine- provided crankplay is within spec. Thanks!

m21sniper · 07-31-2009, 08:50 PM

Possible TBF?

Check the torque tube pre-load.

american-kiwi · american-kiwi's Garage

that amount of shaving is nothing to worry about...wait untill you pull the one out of the trans!!...those give you a scare!...but the same..its fine.....dont panic

m21sniper · 07-31-2009, 09:03 PM

I tend to agree, but it's best to be safe and check the pre-load on the torque tube.

Herr-Kuhn · 07-31-2009, 09:08 PM

That little bit of metal is nothing...if you can't see the magnet when you pull the plug then it is time to worry. The magnet is there to catch those size particles.

Danglerb · 07-31-2009, 10:14 PM

All the same, check the crank end play.

I would also cut open the oil filter and spread it out for a look.

american-kiwi · american-kiwi's Garage

funny you should say that mike...i cut open the fuel filter in the wheel well after the #2 pump went bad in the 78...boy!!...load of crap in there!...some large bits of pump motor bearings!!

928Guy · 08-05-2009, 10:58 AM

That is absolutely a normal amount of metal on that magnet. No need to panic at all. It is SOP to check axial endplay on the crank before purchase, but hopefully that won't be an issue for you at this point. Check your endplay, replace your fuel lines, replace your timing belt (with Porsche belt only), install a Porkensioner, and a PKlamp or a Constantine clamp to prevent shaft migration into the future..