Chris NottAH Fabrications
Results 1 to 4 of 4
  1. #1
    Reverse Gear

    Status
    Offline
    Join Date
    Jan 2009
    Posts
    3

    2.5 V6 TDI Oil Leak and Soot

    Hi All,

    My first post on these forums! I have a 2.5 V6 TDI Passat which has developed a bit of an oil leak. Having searched the forum it seems like a fairly common one.

    I've just read the rather excellent "Replacing crankcase breather" thread and plan to attempt this soon.

    The actual leak is visible "between the V" - If I look just in front of the oil filter there is a big black pool of oil. There is also a load of oil on and around the injector pipes where they leave the fuel pump. Underneath, there is a bit of an oil slick, its hard to pin point but its in the middle of the car, inline with the anti roll bar.

    The other problem is the amount of soot in the engine bay. There's loads of it! It's dry soot and wipes off easily but something tells me it's not normal. If I wipe it off then its back within a few thousand miles.

    Pictures speak a thousand words, so here's some to look at:

    Large amount of soot behind the turbo (on the firewall):


    Hard to make out, but there is a pool of oil in front of the oil filter:


    Another shot showing the soot problem:


    Just to the right of the EGR you can see soot splattered on the right hand rocker cover, and lots of soot around the engine cover mount:


    That's dirty, picture of the firewall:


    Lots of black between the V, and lots of soot from the EGR (to the right):


    Another shot of the EGR dirt:


    (ignore oil on the turbo shield, I spilt some during the oil change)





    So there we have it, a very dirty oily engine. I should mention the car has done 180k so some muck is to be expected. I have previously taken the inlet manifold off and cleaned it out. I noticed during the last oil change that the oil filter housing was half full with oil, so I had to submerge the oil filter in oil during fitting. I'm not sure if this is normal, is there some kind of anti drain valve?

    The only other problems I've noticed are it uses some coolant (needs topping up every few thousand) and it makes quite a lot of blue smoke if you rev it when its not warmed up. Also I took it on a motorway run recently and the low oil warning light came on. I checked the level and it seemed fine...

    Finally, the previous owner said something had been modified (possibly by VW) to prevent the intake manifold from sooting up. I'm not sure what this could be but I was thinking perhaps the soot is being dumped into the engine bay rather than being re-circulated.

    Can anyone suggest what I can check to reduce the soot situation and pinpoint the oil leak?

    Many thanks,
    Henry
    Last edited by blueice; 1st February 2009 at 18:17.

  2. # ADS
    ADS
    Join Date
    Always
    Posts
    Many
     
  3. #2
    Neutral

    Status
    Offline
    Join Date
    Feb 2007
    Posts
    92
    Where does the EGR pipe lead to after the vacuum valve? I think mine connects to the turbo but I can't remember for sure. If the previous owner disabled the EGR then I wonder how. Is yours blanked off?
    2010 A6 Avant TDI S-Line LeMans
    1999 A6 Avant 2.5 TDI Quattro - gone, not forgotten.

  4. #3
    fjtwelve's Avatar
    Moderator

    Status
    Offline
    Join Date
    Jan 2006
    Location
    Falmouth, Cornwall
    Posts
    765
    Coolant loss plus oil leak - have to say head gasket has to be suspect
    Blue smoke when cold - Definitely blue? Not just a bit of rich mixture while the engine is cold? What year is your car? Pre 2001 engines have various problems with the top end by the time they get to your mileage. Likely to be oil coming into the cylinder from the top end.
    Oil light on when level is ok is likely to be oil pressure rather than oil leak, in my expensive experience thats the oil pump, but it would pay you to check some of the less expensive items first, crankcase breather is a good one.
    Soot everywhere - think there's a problem with your egr valve or associated pipework which is blowing exhaust gas into the engine compartment. Your last photo shows the soot all around the egr valve. If the exhaust was blowing you'd know about it.
    2001 A6 Avant 2.5TDi quattro Sport 180hp+TurboDynamics MD438 hybrid+Bosio Race683s+3" exhaust+Celtic Tuning remap - now with adamss24 replaced with runabout
    2007 BMW 535d AM Sport + Celtic remap
    2004 A4 Avant 1.9TDi quattro Sport 130hp + Superchip - sold & replaced by
    2005 Audi TT 1.8T
    1988 Yamaha FJ1200 120hp finally traded after 23 years for
    1986 Yamaha FJ100 (1300 barrels shhh!) with too many bits to mention
    2011 BMW 320d M Sport son #1
    2004 Suzuki SV650 S son #2

  5. #4
    Reverse Gear

    Status
    Offline
    Join Date
    Jan 2009
    Posts
    3
    Thanks for the suggestions.

    The smoke is definitely blue, but it's not pouring out all of the time, so I'm not going to worry (yet!) It's a 1999 vintage, so maybe it is a top end issue.

    I'm pretty sure the EGR isn't blocked off (although I found a great guide to doing so a while back - I wonder if it would be worth while?)

    You're right, there is a lot of soot around the EGR. I can't understand this, as I thought the EGR recirculated hot gas, not vented it into the engine compartment.

    I didn't think there was much EGR pipework, just a pipe from exhaust to the EGR valve and then from the EGR to the intake (plus the vacuum line).

    I'll probably remove it when I get around to the crankcase breather and have a look inside.

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO