Club 80-90 Forums

Hope I have this in the right subforum.

The DJ engine have a unit that sits between the oil filter and case. It is fed coolant which circulates around warming the coolant or the oil dependant on your view point I guess.

They are common place on VAG vehicles.

Years ago I had one of these spontaneously rupture internally on a diesel Audi A4. It dumped the oil into the coolant system and made a real mess.

My question is whether this is a known issue with type25s or whether it is a diesel thing, or I was just unlucky.

Engine out at present so I considering some preventative maintenance.

Matt

VW's oil interwarmer is really an emissions device. It helps to warm the oil in a cold engine because it is plumbed in on the coolant bypass circuit (which allows coolant to circulate around the engine before the thermostat opens) then once the oil is hot and the stat opens, it dumps a small amount of heat into the coolant by virtue of the differential temperatures.
These donut type heat exchangers are known to be bad for restricting flow and thats not great with the wbx high volume/lower pressure oil pump and system.
They are even fitted to 1.8T engines and they are known for making black treacle in the sump, so what does that tell you about their oil cooling effectiveness?
A thermostatic cooler with a "radiator" in the bottom of the D post is really effective, but the hoses and oil stat become long service interval items.

Thanks for the explanation. My Audi was a 1.8td.

I'm not keen on the donut unit, based on my part experience.

I was interested to see if other wbx owners had similar experiences, or if I am an anomaly.

Matt

I am anti-donut interwarmers too. I've run a 2.1 MV for 6 years without one, no problem. After a few years however, I did swap out my 87C water thermostat for a 80C thermostat; the water temp needle moved to 12 o'clock from 1 o'clock, so that was nice. The vehicle has got a radiator, so let it do its job & cool the engine. I think the DJ's run a bit hotter, so I'd go with SB's recommendation on that front - cooler in D-pillar with thermostatic 80C sandwich plate. VW did not fit donuts to DG's. But yeah - VW still using them, I have a 1.9TDI engine from 1993 with one.