02 Jetta white smoke

Discussion in 'VW Mk4 Jetta, Golf, New Beetle, Passat TDI forum' started by Abasinger, Oct 11, 2016.

  1. Abasinger

    Abasinger New Member

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    2002 VW Jetta TDI
    Location:
    Ohio
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    Hello,

    I have a 2002 Jetta, alh engine, auto transmission. Have owned it for approx. 6 months. Noticed roughly 2-3 months after we got it that it would smoke white after startup just for 5 seconds or so. It smells very much like raw fuel. The other thing is it is random. Sometimes no (or very very little) smoke, some times a small cloud that you can very easily see in the mirror.

    Before you get too excited, it does it when starting "cold" in 90* weather, so it's not the glow plugs. I did replace one that was bad, all others ohm out good.

    I tested each nozzle. #3 was spraying very poorly, and would open around 1200 psi. #4 would open a little early around 1900ish if I remember. None of the nozzles dripped fuel at the nozzle under a test pressure close to the valve opening pressure.

    Replaced #3 injector. No different. Removed intake and exhaust manifold and started engine. Smoke appeared to mostly be coming from #2 cylinder. Removed head promptly to see. #2 piston was noticeably wet with fuel compared to the other cylinders, and the next day it was dry from evaporation. Removed all four pistons and re ringed them. The top compression rings were very soft and could be spread out. Honed the cylinders, cleaned, and reinstalled pistons with new rod bearings and bolts. Installed head with new gasket/bolts, manifolds, and retimed engine with new timing belt, water pump, pulleys, etc (was due). Timing is set to the advanced side via vag-com.

    No different. Changed #2 nozzle. No different.

    The smoke is not like when a diesel is catching and trying to start, it is an easy roll out the tailpipe. Engine always starts quickly even without waiting on glowplugs. It has good power and does not smoke during driving, except for an occasional black haze here and there during a hard acceleration. You can drive it for a while, shut it off for a couple hours, and it might smoke, or might not.

    It does not burn oil or coolant( just took it on a 1600 mile round trip, no issues).

    The intake manifold had some buildup, but I did not have time to clean it out, and it really didn't seem that bad.

    The turbo did not appear to be leaking oil, and had good bearing play.

    Before I put the other two nozzles in it, has anyone come across this?

    Anthony
     
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  2. chittychittybangbang

    chittychittybangbang Administrator

    Joined:
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    23,862
    Car:
    2006 Jetta TDI
    Location:
    CT
    Best guess is that it's related to fuel management. I don't know why it would do it only on #2 though. I doubt changing more injectors or nozzles will fix it.

    If it's just an occasional tiny puff and it doesn't cause any problems, I wouldn't worry too much, unless you want to dig more and spend more money.
     
  3. Abasinger

    Abasinger New Member

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    2002 VW Jetta TDI
    Location:
    Ohio
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    Maybe the #2 thing was just a fluke observation, but sure seemed like that cylinder was wet with fuel when I took head off.

    How did I know you were going to say that about the tiny puff and not to worry :) I would call it more than a puff. Puts a small cloud out that can haze garage up with door open and start it with tailpipe pointing out.

    It's really just annoying, it does run great otherwise. It does run a little (slight misfire on random strokes) rough until the smoke stops, which does not take long. Sometimes it idles rougher than others( sometimes can't tell). But every time it starts and there's no smoke, the idle is very smooth and no misfire.

    I replaced valve stem seals yesterday, sort of smoked some thins morning. I changed them just to rule out, didn't actually think it would do the trick.

    I guess I now wonder if there is a fuel drain back issue or air intrusion, any bad spots on these cars?

    Ordered another injector.

    To answer your question, yes I do want to dig further :) any other suggestions?

    Thanks
    Anthony
     
  4. dadeamann

    dadeamann New Member

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    2004 TDI jetta wagen BEW
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    milwaukee
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    ive got the same thing goiing on in my 2004 bew. a good amount of smoke at startup and just a little bit of a rough idle for like a min. this is in nice weather. once it drops down its harder to start. recently i started it on a colder morning probably close to around 40 degrees and i did get glow plug faults. all four.
     
  5. Abasinger

    Abasinger New Member

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    Ohio
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    Ok, might as well give an update.

    Tried retarding the timing to low end of spec just to see if it made a difference in startup smoke, nope.

    I ended up putting a new #4 injector in, didnt make a difference. Replaced #1 and about the same time got a fault for a bad glowplug and found #2 was open.

    I had replaced #3 glowplug 6 months or so before #2 failed, and all the other ones ohmed out correct so I ordered spares and left them be. Replaced the other 3 glowplugs at this time.

    Understand that it would take a week of starting the engine from cold to verify if smoking problem was there or not( due to the randomness of it) .

    Since then, it has not had one issue with starting smoke, or rough idle. Was it the glowplug or the injector? I am leaning towards injector #1 because it would exhibit this problem in 90* weather.

    SO... this was a very complicated issue with no great way to troubleshoot. I took steps to troubleshoot parts before replacement but nothing pointed to the root cause, so I began using the different parts to troubleshoot and find the issue.

    If anyone else is having this problem, make sure your glowplugs are all working. This is easy to do and cheap. Take them out and hook them up to a battery to physically see that they glow red hot. I wouldn't argue against replacing them all at once.

    Next I would check the timing and make sure it's not way out (mine was not) , then I would start checking the injectors... though in this case I pop tested them and they seemed fine. The only question I had about my test procedure with the injectors is that they were not stone cold, I had moved the car 50 feet or so to test them. Who knows..

    Anyways, problem solved (even after much a-do)
     
  6. Abasinger

    Abasinger New Member

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    This is about what it was doing. Maybe not idling even that rough. Sometimes more smoke than that sometimes less. (This was not my car)

     
  7. crsmp5

    crsmp5 Well-Known Member

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    :rolleyes: new rings are not seated/broken in yet is your #1 flaw of worry...

    #2 glowplug was original issue... but now you added to it.. the fact #2 was wet unlike the other 3 shows 1, low on compression, or 2 glow plug not working right... 3 could have been bad injector spray... but pop tested that to see it sprayed ok..

    i guess the ip could be failing.. and #2 is lacking pressure to "spray" fuel and instead of a mist its squirting streams of fuel... which is much harder to burn vs a mist..

    but till rings are seated/broken in.. its going to smoke due to compression on cold engine..
     
  8. Abasinger

    Abasinger New Member

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    I will respectfully disagree.

    The issue was there before and after the ring job, the engine had 2500 miles on it from ring replacement to injector swap, so they would have seated well enough in that time, and it also is not burning oil at all, so I maintain that the rings were not a contributing factor.

    It was either the plugs or injectors. I had taken all the plugs out though before the major engine work and they all glowed fine if I remember right...maybe I'm mistaken on that one though.

    Anyways, it hasn't smoked for 2 months or so, so I'm satisfied. I now also have a nice fresh engine minus main bearings, which don't see the most wear anyways.

    Thanks
     

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