so the head has been checked... still oil in the coolant... - page 1 - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• so the head has been checked... still oil in the coolant... by mk2vr6 on 10 Sep, 2007 17:56
• So after sending the head to a machine shop and finding out its 100% fine, the car is back together and runs great.
  
  However, there still appears to be oil in the coolant.  After draining the coolant the first time, there was a LOT of oil in there.  We ran about 2 bottles of kleen-flo rad flush through, got a bunch of gunk out of there, and then another 3 or 4 flushes with just water.  There is still oil in there.
  
  Is there any real sure-fire way or other things to look for to determine if the block is really cracked?  It's gotta be between the oil and coolant passages because the car runs 100% and does not overheat or show any other signs of a cracked block or head. Plus, the head has been checked and new gaskets put in.
  
  I'm running out of ideas here...  is it worth it to change the oil cooler?  I've read that can sometimes be the issue...  how difficult is that to replace?
  
  Give me any other ideas, its my only 'working' car now...  ha.
• #1 by dieseldubber on 10 Sep, 2007 21:51
• wow from my understanding changing the oil cooler would be much simpler than what you just went through. It is the thing which the oil filter threads into right in front of the engine bay. I also have oil in the coolant and am gonna pressure test my oil cooler first for possible cross contamination and go from there.
• #2 by jtanguay on 12 Sep, 2007 09:37
• yea seriously dude... i changed my own oil cooler... $75 part.  also did my t-stat and a coolant 'flush' while i was in there.  the most painful part was removing those stupid hose clamps.  theres a tool somewhere that makes it easy, but without it... it is uber painful!!!  i didn't want to remove my a/c lines, otherwise that would have made it SUPER easy!  i think its a 27mm nut holding the oil cooler on.  i didn't buy a new rubber seal for the cooler and i think im leaking a minor amount of oil from it (but i dont care) so do yourself a favour and get a new seal for a buck.  all of my oil in coolant and coolant in oil problems dissapeared afterwards...
  
  good luck!  at least you know your head is good though...
• #3 by mk2vr6 on 12 Sep, 2007 09:44
• Thats it?  just a 27mm nut?  I'll give that a try next but so far it appears the oil is being cleaned out with every flush.
• #4 by jtanguay on 13 Sep, 2007 06:56
• Quote from: "mk2vr6"

  Thats it?  just a 27mm nut?  I'll give that a try next but so far it appears the oil is being cleaned out with every flush.

  
  
  yep thats it.. 27mm i'm pretty sure..  and the tool to remove the water hose clamps. you don't need it, but it will make life easier.   (i recommend you buy some ratcheting hose clamps)
• #5 by mk2vr6 on 13 Sep, 2007 07:06
• Do the oil pressure senders need to be removed as well?
• #6 by burn_your_money on 13 Sep, 2007 11:58
• No. You unscrew the oil filter, then the threaded hollow rod has a 27mm (or w/e size) nut on it. You remove that and all the hoses attached to the oil cooler/warmer and it should slide right off.
  
  Are you sure that you are getting new oil in the coolant though? It might just be oil trapped in the cooling system somewhere and it is just slowly releasing. Oil is a major PITA to get out of the cooling system
• #7 by mk2vr6 on 13 Sep, 2007 15:12
• Yea, it could be, but i've flushed it about 4 times now so I'm still waiting for it to be clean before I can tell if its the block or not...
• #8 by BlackTieTD on 14 Sep, 2007 09:49
• oil cooler! i had one of these come apart. its just a nut holding it and if the filter is screwed on too tight, you can actually loosen off the cooler nut when you unscrew the filter.... or something like that. was a long time ago  :lol: check that before you dig into the block or anything that serious.
• #9 by mk2vr6 on 14 Sep, 2007 10:00
• Is there anyway to pressure test the oil cooler?
  
  I'll have to give that a try.
  
  The first time after dumping the old coolant, there seemed to be more oil than coolant.
  
  I'm running just plain water through at the moment to determine if theres any oil in there and flushing it out...  The water is coming out a brownish grey, almost a 'dusty' colour.  If there was an oil leak from the block into one of the coolant passages, would there be 'blotches' of oil floating to the top of the resevoir, since oil and water do not mix?
• #10 by jtanguay on 14 Sep, 2007 13:27
• Quote from: "mk2vr6"

  Is there anyway to pressure test the oil cooler?
  
  I'll have to give that a try.
  
  The first time after dumping the old coolant, there seemed to be more oil than coolant.
  
  I'm running just plain water through at the moment to determine if theres any oil in there and flushing it out...  The water is coming out a brownish grey, almost a 'dusty' colour.  If there was an oil leak from the block into one of the coolant passages, would there be 'blotches' of oil floating to the top of the resevoir, since oil and water do not mix?

  
  
  you could waste a bunch of time pressure testing an oil cooler, but i wouldn't...  real world conditions are:  temperature - you need to heat up the oil cooler so the metal expands, then flow piping hot coolant & oil through it to actually get some results, because it seems like you have a minor pinhole leak in it.  
  
  you've obviously changed the HG while checking the head, so that is a huge culprit right there crossed off.  just change the oil cooler like me and be done with it!  
• #11 by mk2vr6 on 18 Sep, 2007 06:58
• I've flushed the coolant a couple more times since last time (well, the water I've been running through)... its a bit of a brown colour now, but as far as I can tell, there is no oil floating around in there. It should be floating at the top or in little bubbles, right?
• #12 by lord_verminaard on 18 Sep, 2007 07:33
• I'd change the oil cooler anyway.  It's like one extra step over an oil change.  I've seen OEM oil coolers for less than $75 even.   When it gets cold and oil pressure is really high upon startup, the internals of that cooler could explode and you'd have oil and coolant milkshake in both the oil and cooling systems, and trust me, you DONT want that.  
  
  Brendan
• #13 by TD_Bunny on 13 Dec, 2007 10:49
• this may be self explanitory but if the oil cooler is leaking the coolant in the expansion tank will continue to get worse and worse right? I just put in a brand new oil cooler with gasket and now it seems i am having more issues with oil in my coolant. However, after the initial run through of the coolant i dont think it is getting worse. Already sux as i just put in new G12 coolant and it went from nice and pink to brown!
• #14 by smutts on 16 Dec, 2007 08:59
• They are bit of an arse to sort out afterwards, Washing machine powder is excellent for this at least in Europe. DO NOT use caustic soda, sodium hydroxide, washing soda, sodium carbonate, dishwasher powder etc. as your aluminium engine components will dissolve like sugar. Just keep changing the water powder mix each day after the commute, and after a week it should be history. Might take longer in winter as the radiator flow is sluggish as it is mostly bypassed. Long nosed locking mole grips are what I use on those wretched hose clamps. Mind your eyes when they fly off!