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I’vehad this issue when I bought my car and have now resolved it:
Oilin the coolant is common and if the car is behaving and driving okay with nosmoke out of the back, then is more than likely just the oil O-Ring seal onyour cooler that sits above the oil filter.
Unscrewthe filter (use a small screw driver on the end of it against the tabs ifneeded). Then unscrew the thin hex-nut I think its about 27mm, with the coolerremoved inspect the seal to see if it is hard and evidence that oil was leakinginto the water. IF possible then plug when end of the cooler and force air intothe other end to see if it still a sealed unit, you can do this in water to seeif any bubbles appear, of if you have a pressure gauge look for a drop inpressure.
Ifyou really want to be sure then buy another cooler with a fresh O-ring seal andfit back on the car, you will not have to drain the engine oil but use somerags for drips.
Nowthe important point here is when tightening up the thin nut DO NOT over tightenit, the torque is very low around 22Nm to 25 Nm. Likewise the oil filter ishand tight only.
Flushthe system multiple times using hot water via a hose, I did this by making asmall connector that plugged into my house hot tap on the shower. You need thehot water to get the sludge out and it took me a good 3-4 times to clear itfully !
Removethe header tank from the car and empty out, then use some white spirit orpetrol to swish around, followed by washing up liquid and then lots of hotwater and leaver to drain out.
Disconnectthe inlet and outlet to the heater core that goes into the cabin and put thehot water on the outlet of the pipe (reverse) to clear the gunk, then connectthe hose to the engine hoses and clear the system via the two pipes thatconnected into the header tank that is now removed. Drain the main radiator atthe base using the tap or just pull the sensor clip off if jammed and flush thegunk out.
Connectall back up and will fill the coolant, you may need to bleed the system a fewtimes until it settles using the small screw on the metal rail. Repeat theprocess another 2 times and check in the header tank for traces of oily gunk,if you’ve done everything correctly, after 3 times it will pretty much be gone, then add the anti-freeze!
Minesas clean as a whistle and pink !
2. Stick your 27mm socket on the nut and break it free. It will spin off the threaded rod. The oil cooler is now free to slide down and off the threaded rod.
This is a view looking up at the housing. You can see the original o-ring stuck to the housing.
Old o-ring.
3. Clean up the contact surface of the oil cooler before snapping the new o-ring into place. The two tabs on the o-ring latch onto the hooks on the oil cooler. Lubricate the o-ring with some oil before putting everything back together to help it seal.
New o-ring in place.
Cleaned up oil cooler secured back into place.
Torque the nut to 18 foot pounds. I had to use an 18" extension to get an angle that would allow my torque wrench to fit (not ideal.)
I'm planing to install an external oil cooler, im confusing about the sandwich adapter thermal or non thermal can you help me which one to buy. thanks in advance
04-18-2017, 09:01 AM
A4 B6 1.8 BASE. OIL ON COOLANT RESERVOIR
