WR Ur quattro, oil filter housing.

Colin Aitchison · 30-07-23, 04:05 PM

Hi Guys on the scrounge for information, my WR Ur quattro 1984 oil temp goes up very quickly and take for ever to come back down, when I was parking the car the other night, I went below the car to feel how hot the oil cooler was, it was quite cold, from memory it is normally very hot.
I may be corrected on this, but, my thought are that the oil filter housing has a bimetal oil stat and what looks like a piston and spring in it on the parts menu, this is accessible from the cover on the end plate of the housing, has anyone had one of these in bits or has any other useful information on repairs, I do have a couple of spare housing but not wanting to bin a part if it might be something very simple to fix like a stuck piston.
Thanks in advance.

urquattr085 · 30-07-23, 08:14 PM

Hi Colin, no first hand knowledge of this unfortunately, but looking at the parts diagrams I can't see anything that would control flow to the oil cooler that would be temperature controlled.

It would make sense for there to be a bypass solution until warmed up, but I don't see how the spring and piston arrangement does that, seems more pressure related.

Side thought - is it possible one of the lines of the cooler has a blockage restricting oil flow?

tractor Dave · 31-07-23, 06:13 AM

The piston and spring under the temp sensor is a pressure relief valve. As above, might be blocked or partially blocked. As it's below the filter housing the oil inside never gets drained during an oil change and crud will always sink to the bottom.

Colin Aitchison · 31-07-23, 05:40 PM

Thanks guys, I will need to remove and dismantle, I have had the car for 32 years and this in my mind is the original filter housing, will report back my findings, on holiday next week, so could be a couple of weeks.

Colin Aitchison · 17-08-23, 03:32 PM

Hi Guys, Removed the oil filter housing last night, removed the end plate with the four M6 bolts, the spring was intact and the piston did move freely, the piston is round with a large slot in the side, the piston also has two radial grooves close together but no seals in grooves, close to the middle of the piston, in the center of the piston there is a steel plate with 4 equal size holes, the steel plate has an extrusion on both sides of the plate, this extrusion dose sit against a raise area on the end plate that I removed to gain access to the piston, on the internal center face of the extrusion their is text "100Deg" I take it from this the oil stat is built into the piston. Look for new piston online, I knew this would be a longshot, could not find any for sale, so back to shed to dig out a second hand oil filter housing.

30-07-23, 08:14 PM	#2
urquattr085 Senior Member Classic Audi Club Member Join Date: May 2016 Location: Displaced Northerner in Essex Posts: 1,528	Hi Colin, no first hand knowledge of this unfortunately, but looking at the parts diagrams I can't see anything that would control flow to the oil cooler that would be temperature controlled. It would make sense for there to be a bypass solution until warmed up, but I don't see how the spring and piston arrangement does that, seems more pressure related. Side thought - is it possible one of the lines of the cooler has a blockage restricting oil flow? __________________ 1985 WR quattro 2010 A6 3.0Tdi Allroad 2010 A3 1.4 tfsi Sport - Sold but still in the family 1984 80 Quattro - Sold many moons ago 1981 Coupe GT - Sold to buy above

31-07-23, 06:13 AM	#3
tractor Dave Senior Member Classic Audi Club Member Join Date: Apr 2018 Location: Wales Posts: 1,162	The piston and spring under the temp sensor is a pressure relief valve. As above, might be blocked or partially blocked. As it's below the filter housing the oil inside never gets drained during an oil change and crud will always sink to the bottom.

31-07-23, 05:40 PM	#4
Colin Aitchison Senior Member Classic Audi Club Member Join Date: Dec 2013 Location: Back home in Tillicoultry Posts: 1,311	Thanks guys, I will need to remove and dismantle, I have had the car for 32 years and this in my mind is the original filter housing, will report back my findings, on holiday next week, so could be a couple of weeks.

17-08-23, 03:32 PM	#5
Colin Aitchison Senior Member Classic Audi Club Member Join Date: Dec 2013 Location: Back home in Tillicoultry Posts: 1,311	Hi Guys, Removed the oil filter housing last night, removed the end plate with the four M6 bolts, the spring was intact and the piston did move freely, the piston is round with a large slot in the side, the piston also has two radial grooves close together but no seals in grooves, close to the middle of the piston, in the center of the piston there is a steel plate with 4 equal size holes, the steel plate has an extrusion on both sides of the plate, this extrusion dose sit against a raise area on the end plate that I removed to gain access to the piston, on the internal center face of the extrusion their is text "100Deg" I take it from this the oil stat is built into the piston. Look for new piston online, I knew this would be a longshot, could not find any for sale, so back to shed to dig out a second hand oil filter housing.