Announcement

Collapse
No announcement yet.

Attack of the foamy oil - Part III

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Attack of the foamy oil - Part III

    As of this weekend I am still perplexed by the foamy oil problem. Here's what I tried:

    Pulled the oil pan again and removed the S4 windage tray altogether. Reinstalled stock 3B baffle. Removed the oil pick-up tube and packed the oil pump with white assembly grease - as per George Baxter's suggestion - thinking that the oil system hasn't been properly primed yet. Reinstalled pick-up with new gasket and lock plate, and reinstalled the pan. Filled oil again and removed spark plugs. Cranked starter for a couple of 15 second durations to prime the oil pump. I was amazed at how easily the engine tuns without compression, and nearly silent too! I had to get someone to confirm that the engine was actually turning! Interestingly, as I was cranking I kept an eye on the analog oil pressure gauge. During the 15 second crank the gauge would rise to just over 2 bar. Once it reached about 1.8 bar, the oil pressure warning in the Autocheck came on, leading me to suspect that the 1.8 bar pressure sender is faulty. I don't think I have an oil pressure problem. The other interesting and puzzling thing is that after the priming session I checked the oil to see if it was frothy, but it wasn't. It looked totally normal. I had my hopes up! However after installing the plugs again, I started it and let it run for about a minute. Oil pressure gauge showed 5 bar, but the warning still came on almost immediately. Shut it down and checked the oil and it again was frothy! At this point I'm more concerned with the foaming oil than with the pressure warning. The gauge reads OK and I don't hear any lifter ticking. The engine sounds and runs great. I'm going to replace the 1.8 bar sensor next time I'm there. It could be that it is stuck in the open (default) position after having sat for a couple of years. For the life of me though, I cannot figure out this foaming oil problem! This has held me up for about a month now. I realize I've probably gleaned all the info I'm going to get out of this group and others, but if anyone has some sort of wild brainstorm, I'd love to hear it!

    Regards,

    Ben
    Ben
    Calgary, Alberta
    Canada
    1991 CQ e//S2 w/ RS2 spec 3B 20vt
    Panther Black Metallic
    www.moda-architecture.ca

  • #2
    Haven't caught this thread before so sorry if any of this has been suggested already...

    Sounds like a maybe a head gasket leak to me - have you checked cylinder compression - both hot and cold ?

    Is the pickup pipe completely clear - thinking maybe oil starvation would cause this... ?

    Is the crankcase breathing properly - wondering if some aftermarket breather system is installed incorrectly in some weird way - can't think how it would cause frothy oil though.

    Its going to be something stupid - hopefully inexpensive !

    The 1.8bar switch can be easily tested for short or open with a multimeter - from memory I think that switch is supposed to be open when pressure is above 1.8bar... Don't take my word for that - I'll have to check the schematics, but I think this is one of Audis stupid fault intolerant wiring anomolies that our cars are blessed with.


    Paul
    Paul Nugent
    Webmaster http://S2central.net
    Administrator http://S2forum.com

    1994 S2 Coupe ABY - aka Project Lazarus
    2001 A6 allroad 2.5TDi - family tank
    2003 S4 Avant 4.2 V8 - daily burble

    Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

    There are only 10 kinds of people that understand binary - those that do, and those that don't

    Comment


    • #3
      The head gasket (and all other seals, gaskets & hoses) is brand new. The engine is virtually brand new. I did a compression test (cold) last week and it came up 134, 135, 139, 134, 135. This is the first time it has been run since it was installed. Could it be that it just needs sufficient time for the oil to circulate through? Total run time at idle is about 5 minutes. I have yet to rev the engine past idle.

      The pick up tube is free and the oil pump rotates properly.

      I had similar thoughts about the crank case breather system, but everything is bone-stock and new. I'm really stumped!
      Ben
      Calgary, Alberta
      Canada
      1991 CQ e//S2 w/ RS2 spec 3B 20vt
      Panther Black Metallic
      www.moda-architecture.ca

      Comment


      • #4
        I can't imagine there's many ways to get the oil to become frothy.
        Is there any possibility that some cleaning/degreasing agent was trapped in the block prior to filling and starting the engine? That could 'possibly' cause frothing. Perhaps air is somehow being drawn into the oil flow before it gets to the pump, or while it's in the pump..:confused:
        I'm now hoping I don't have the same problems when I put my motor back together. Good luck finding the solution.
        91 Modded 3B
        14 A6 Avant Black Edition

        Comment

        Working...
        X