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bad turbo or worse?
by
irdiver
on 21 Feb, 2006 18:46
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here is the background story to my problem...
i bought a '91 eco diesel from a good friend who was the original owner, that was all well and good. it had been sitting with very little driving for two years, not so good. so i have been getting the thing back into drivable status lately. now here is the problem, i have changed every fluid in the car, cam belt, hoses, put in a new turbo rebuild kit due to wobble in the shaft, new fuel filter up front, over 3/4 tank of new diesel, and everything seemed fine in the city. before i rebuilt the turbo and after i never really hear the turbo spool up, but i didnt think much of it.
anyway i took the first highway road trip, 36 miles on the interstate each way, and about 25 or so miles into it, the engine temp has crept up, then it lost power and started beltching black smoke like i just lost the engine. i slowed the car down for a minute or two the smoke stops and the car runs like nothing happened. so i figure odd must be carbon somewhere in the system, on the way home about the same point in the road it does it again and afterwards is fine again.
the enigne has 273k miles on it, seems to run fine, compression test couple of years ago said 475psi on every cylinder, but one valve seems to be tapping a bit louder than the rest.
so what are the thoughts? turbo? valve seal leak? or not oil related at all? still bad diesel in the tank? im lost help! Sad
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#1
by
Master ACiD
on 21 Feb, 2006 19:17
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he typed that he put a new fuel filter on it.
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#2
by
myke_w
on 21 Feb, 2006 19:21
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Black smoke?
Maybe a stuck open injector?
Have you driven it since this episode? Perhaps it was blowing oil out of the exhaust and you just needed to run it out?
I wouldn't suspect the worst just yet..
Post back with your thoughts.
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#3
by
irdiver
on 22 Feb, 2006 06:55
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the fuel filter in the engine compartment is new. after each of the huge smoke cloud i had to drive it another 20+ miles to get where i was going and it didnt do it, even running it back up to 70-73 where i was sitting on the highway. i was talking to Jack at vwdieselparts and he was thinking it sounded like a turbo, but before throwing down huge amounts of money on a turbo i want to make sure that is the fix rather than the $.05 part.
i do know the turbo has a total swing of 1/4 inch or so out of the spindle in the turbo on the intake side. think i need to replace the guts?
oh i just thought about where i was on the highway, both times were just after a long climb up hill, 1 mile incline or so. thanks all!
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#4
by
irdiver
on 22 Feb, 2006 08:54
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when i had it apart last month the turbo parts all looked good and no obvious issues, bent or mangled turbo bits. but i am no expert when it comes to turbo's, the best bet will probably be to replace the whole spinning parts assembly. think i should replace all of the wear parts inside again? they have maybe 200 miles on them since the rebuild.
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#5
by
fspGTD
on 22 Feb, 2006 17:11
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FYI - I measured the radial play on a couple good turbos recently... not a KKK K14, but VW 1.6TD turbos. A 1.6lTD Garrett good used, before rebuild (which is currently in progress) had a measured radial play of .018" and an axial play of about .0025". As I proceed forward with the rebuild, I'm going to measure and report back the difference in the play the new thrust and journal bearings make, but this play is nowhere near .25", and is only going to get smaller, not bigger.
I recall the radial play of my 1.6lTD KKK turbo being somewhere around or even under .012" after I rebuilt it.
You'll need a dial indicator setup and a way of securely fixing it with your turbo in proper orientation and then you wiggle the shaft and watch the effect on the gauge to measure the radial and axial play. I recommend using a magnetic dial indicator stand and latching it onto the flat-machined anvil found on the back of some vices, and then clamp the turbo's center section securely in the vice jaws to hold it securely.
Was the color of the smoke blue (which would indicate burned oil) or more dark grey/black (which would point more towards inefficiently combusted diesel?) Did you engine "run on" (accelerate by itself without your throttle input) when this episode happened? If so, it is likely to be excessive blow-by gasses and oil vapors in the crankcase recirculation hose. That is most often caused by worn out or poorly sealing piston rings. The way to test if this is the problem would be to re-route your blowby recirculation tube down down under the car instead of into the intake, and see if that stops the smoking/accelerating eposides. Or, you can install a crankcase vent filter (like a MANN provent) in line with the blowby recirculation hose to completely remove the oil droplets (and additional fuel source) from the air intake.
Hope this, and other tips mentioned by e-mail (now's a good time for a boost gauge) will prove helpful... good luck!
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#6
by
irdiver
on 23 Feb, 2006 19:32
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i got a chance to go look at the engine again tonight and noticed that the dipstick had slid up an inch or so and looks like there was an oil spray happening on the engine. wondering if i am pressurizing the oil system causing the oil to spray out of the dipstick and thus cause the sudden smoke behind and then stopping once the pressure is off.
blowby from the rings or from the turbo? i would guess it is time for a ring job but what are the thoughts?
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#7
by
fspGTD
on 28 Feb, 2006 11:30
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My GTD autocrosser did the "dipstick push up" once:
http://www.vwdiesel.net/phpBB/viewtopic.php?t=219which I "fixed" by improving the crankcase ventilation of the motor. However, this only cured the symptom and not the real problem of excessive blowby.
After a lot of fussing around trying to make sense of what was really happening, I finally diagnosed the exessively leaking rings via a dry and wet leak down test. I reported the results here:
http://www.vwdiesel.net/phpBB/viewtopic.php?t=406&start=93I didn't have any problems with runaway on this motor, but I would expect it because I didn't have the blowby gasses getting recirculated back into the intake. I did experience some hard starting problems in the cold.
It sounds like a leak down test could do your Jetta some good too... Do it dry first, and then if the leakage seems excessive, repeat with a wet test (put oil in and repeat the test.) The oil will temporarily seal your rings, so if you find that the excessive dry leakage stops with the oil, you've pinpointed the rings as the cause. Hope this helps!
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#8
by
irdiver
on 01 Mar, 2006 08:58
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after doing some real thinking, it is probably just time to rebuild the engine. next step is finding someone with the experience to do it quickly or finding a donor na engine to run while i rebuild the td... a bene of the eco diesel it has a na injector pump setup. so i can drop in a na and go.
anyone know of a good used na 1.6 in the southeast US or even better FL? thanks!