Author Topic: ecess Oil consumption in 91 ecodiesel?  (Read 9268 times)

Cruciform

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ecess Oil consumption in 91 ecodiesel?
« on: May 08, 2004, 05:49:06 PM »
Hello,

 I just picked up a decent running, albiet a little rough around the edges, 91 TD w/115k on it for $200. very stoked

the PO said it used a ton of oil, and there is alot of empty containers in the back. 250 mi per qt!??!

now I have done a little research, and know a bit about VW diesels, so here's what I have so far-

Engine smokes on startup. bluish grey (looks like oil to me) and continues for a few minutes. then it seems to clear up. I wouldn't say it's billowing, but maybe twice what I would expect from a diesel
I did put a few miles on it, and it seems to have plenty of power (for an eco diesel)
it seems to start easily, but the PO said It wouldn't start in the winter easily (it's 60 plus here now)

It also sounds like one of the lifters has collapsed-I've had a lot of VW's, and usually they pump up eventully, but not this one. it speeds up with RPMs, but doesn't get louder, just faster. I'm not entirely positive it's a lifter-maybe a broken spring, or something. I've also heard of a bad injector causing knocking?

There are only a few things that would cause excessive oil consumption-
A) bad rings
B) turbo seals
C) external leaks
D) headgasket
E)valvestem seals

mind you I haven't done a compression test yet (need to get a tester)
but the car runs very well and seems to have decent power. It also doesn't seem to "run on" like worn rings could cause it to do (probably not rings)

It does smoke on startup, but as far as I can see, clears up. (doesn't lead me to belive the turbo seals are bad)

 there are no excessive external leaks

the headgasket seems ok, but there is a little oil in the coolant, not much, possibly from a past headgasket change- no excessive pressure in resevoir
Valve stem seals do cause smoke on startup, but usually it goes away after the car has warmed..and rarely consume much oil.

I'm kinda stumped...

 any tests or things to look for that I've over looked?
 The airfilter was dirty..not horrendesly, but enough. no oil on the filter itself

thanks for any and all advice!

 Percy



Offline HughF

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ecess Oil consumption in 91 ecodiesel?
« Reply #1 on: May 09, 2004, 04:48:33 AM »
As a stop gap until you get your compression tester, remove the oil filler cap from the rocker cover when the engine is running and note if there is any blow-by... you'll spot it as a white sort of water vapour type stuff coming out. If so, you've got worn rings, and your compressions will be down. It might have been driven hard for that 115k miles that's on it, with no respect for the thing when it's cold, and as a result, the combustion products pick up oil mist when they exit the crankcase breather.

I'm new to this bored, I haven't got any experience with VW diesels, but have been running peugeot and Iveco diesels here in the UK now for about 10 years.

Hope that's of some help,
Hugh, Dorset UK

Offline dieseltech

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ecess Oil consumption in 91 ecodiesel?
« Reply #2 on: May 11, 2004, 09:57:38 AM »
here is a test for the turbo seals.   drive the car for 10 min or till its warm and no smoke,  park the car somewhare and let it idle for 30 min to an hour, after that hop in and WATCH THE EXHAUST  give it full throttle for 2 seconds, do that a few times, see any smoke? blue greay. go for a ride, if you see lots of blue/grey out of the exhaust for for the first 30 seconds then clears up. your turbo seals are most likely going. could also be valve guides but rare. i have beat the *** out of every vw diesel i have ownd and never wore out rings or valve guides, but i also use good oil.     oh btw what oil are you using??  i have seen people use 5w 30 oil in a vw diesel and have high consumption. try shell rotella 15w 40 diesel oil.

good luck
86 td jetta power everything dd (update off the road for major resto).  97tdi bare bones, DD
and a private junkyard of various other vw/audi/bmw/peugeot/volvo/toyota diesels!!!
Cummins has the worlds record for being the most efficient engine ever!!!!!
for converting fuel into noise!