1995 940T Cleaning out Oil Cooler??

macs70GLT · Post by **macs70GLT** » 20 Jul 2015, 13:26

Wondering if anyone has experienced excess pressure, or blockage of oil passages in the oil cooler of the 940T? Specifically the coolant oil cooler mounted to the block, oil filter screws onto the cooler.

Car has 190K miles. I have owned it about 40K miles (3.5 years) and always use Mann filters with Pennzoil full synthetic. Car has always used some oil between changes, but is currently using a lot! Appears to be leaking at the filter, though could also be dripping down from the distributor.

Last week I replaced the oil separator box & all hoses so it's not a crankcase pressure problem.

I'm wondering if the filter seat area on the cooler is damaged - though that wouldn't explain why it hasn't always leaked this much.

Thanks

Mike
current 1995 940T (family teens car), Daily Driver (2002 Audi A4 Q 1.8T)
Lars (1988 245, traded at 250K miles) Son of Lars (1998 S70GLT traded at 225K miles)

mika · Post by **mika** » 21 Jul 2015, 13:20

how do you know it is not a crankcase vent issue? Did you do glove test?

I am having same problem on my 940T. I did the PCV system and everything is patent and fresh. (all seals done too) However, the glove test is still failed Just like you, my filter housing area is caked and so is everything under it. There must be blockage somewhere.

q1: I know that with the 850s, if the EGR is clogged, the PCV will act up. Do we have an EGR and if so, where is it?

q2: I thought "oil coolers" are mounted like a radiator up front? Are you saying the filter screws onto an "oil cooler?"

lummert · Post by **lummert** » 21 Jul 2015, 15:19

Investigate replacing the o-rings on the filter adapter to block and filter adapter to oil cooler. Running synthetic oil makes the o-rings leak even more. The o-rings in there now are going to be rock hard and shrunken up enough to leak.

lummert · Post by **lummert** » 21 Jul 2015, 15:21

mika wrote:how do you know it is not a crankcase vent issue? Did you do glove test?

I am having same problem on my 940T. I did the PCV system and everything is patent and fresh. (all seals done too) However, the glove test is still failed Just like you, my filter housing area is caked and so is everything under it. There must be blockage somewhere.

q1: I know that with the 850s, if the EGR is clogged, the PCV will act up. Do we have an EGR and if so, where is it?

q2: I thought "oil coolers" are mounted like a radiator up front? Are you saying the filter screws onto an "oil cooler?"

The oil cooler on later the B230FT is water cooled (sandwich type) and attached to the oil filter adapter.

macs70GLT · Post by **macs70GLT** » 21 Jul 2015, 16:56

@ Mika; on mine (1995) the EGR valve is mounted on a separate bracket that attaches through the oil separator bolt holes. Made replacing it a lot more difficult (I didn't remove the intake manifold). I checked the EGR valve which seemed to work (diaphram intact), and the metal tubes were clear. As Lummert noted the my oil cooler is a sandwich between the filter & an extender attached to the block.

@ Lummert - I may well end up removing it all & replacing the o-rings and cleaning it all up. I'm thinking it is leaking less now that I replaced the breather components (oil separator etc). On a positive note I cleaned up the plastic grate pieces on the bellhousing (?) which remained clean after 70 miles so I think the rear main seal is not the leak!

I'm planning to replace the oil filter first though - in case the old filter seal was still on & I doubled them up (unlikely but who knows) ...