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Author Topic: please help!! possible head gasket gone- aaz  (Read 3817 times)

September 27, 2015, 03:43:58 pm

benmeek94

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please help!! possible head gasket gone- aaz
« on: September 27, 2015, 03:43:58 pm »
hi guys, recently brought a bargain mk3 golf with the 1.9td aaz engine. it only has 83,000 with full vw service history up till 15,000 miles ago, the first owner served it every year even when one year he only done 1,500 miles. it runs a dream so I was very happy with my purchase, my coolant light kept flashing so I checked it and it was topped up with nice clean anti-freeze. sensor went on and off so I put it down to a faulty sensor.

done a nice long 2 hour trip in it and when I got home I thought il check the coolant level one last time, although this time it had abit of oil in it, I am a DIY mechanic and mostly know what im talking about. I knew straight away this is a sign of a head gasket gone. I checked the oil filler cap and no creaminess... no white smoke when it was running either.

I had a quick look online and people said it could also be the oil cooler, so today I have drained the oil and there is 100% no water into the block, it was nice and black. just seems to be the other way around, oil getting into the coolant but again not a lot as I also drained the coolant today and I would say 95% was antifreeze. I have taken all the coolant pipes off and flushed the system through. in most of the pipes is a very thick black gunge, which looks and feels more like grease then oil.

i got the oil cooler off and pressure tested it on my compressor raming air down it and shoving my finger in the other pipe. seems fine to me, i was hope it was hiss out air meaning that would clearly solve my problem, maybe the pressure wasn't enough or something. i have a new oil cooler on the way anyway so when it arrives il top it back up with oil, fit all the pipes back on after trying to clean out as much sludge as possible, top it up with water and start her up and keep checking my expansion tank for oil but i am expecting some as that sludge is probably all in the block ect.

just any ideas guys? my heart is still telling me it cant be the head gasket as that isn't exactly common on these old bullet proof diesel engines, especially one so well serviced with such little miles... or is it just one of those unfortunate things?

if its not is there any other way oil can get into the coolant? because i always thought if it was head gasket you normally loose water into the engine not the other way around...

worst case scenario how much roughly is it to replace the head gasket? because if it is that ive definitely caught it early.
 



Reply #1September 29, 2015, 12:56:12 am

vanbcguy

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Re: please help!! possible head gasket gone- aaz
« Reply #1 on: September 29, 2015, 12:56:12 am »
It's actual far more common for oil to leak in to the coolant than it is for coolant to leak in to the oil - oil pressure is quite a bit higher than coolant pressure. A weak head gasket can let some oil pass at cold startup (when oil pressure is super high) but not let any coolant go the other way.

That said the oil cooler is definitely a good place to start! They definitely can and do fail especially if the coolant is the cheap green stuff and hasn't been changed in a while.
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #2September 29, 2015, 01:43:07 am

libbydiesel

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Re: please help!! possible head gasket gone- aaz
« Reply #2 on: September 29, 2015, 01:43:07 am »
Check the oil cooler first, not by trying to listen for a his, but instead, plug one of the hose nipples and rig a way to apply air pressure to the other one.  Then *submerge the oil cooler in a container of water while maintaining pressure.  Is there a stream of bubbles?

Blown head gaskets are quite common on these engines.  Not as common on the AAZ as on the 1.6s but certainly not rare.

Head gaskets can fail in several different ways.  Oil in the coolant, coolant in the oil, loss of compression in two adjacent cylinders, loss of compression on cyl 1 or 4, exhaust gases in the coolant, coolant in a cylinder (or going out the exhaust), coolant leaking to the exterior, oil leaking to the exterior, etc...  The interesting thing is that it is rare to have more than one symptom.  It just depends on where the leak is occurring on the head gasket.  If it is a leak between one of the coolant channels and one of the oil drains from the head to the block you will get coolant in the oil but no oil in the coolant.  If it is a leak between the high pressure oil channel (between cyl 3+4) and one of the adjacent coolant channels, you will get oil in the coolant but no coolant in the oil.