2.8CRD Weird oil cooler failure
 

Hi
Recently changed the oil and filter on my 2.8CRD GV. When I got under the car I could smell coolant, my coolant header tank had dropped 1/4 inch or so.
As I unscrewed the oil filter I nudged (very gently) the ruber hoses that go to/from the oil cooler located underneath the filter and one of them literally fell off pouring coolant out.

So, question to the forum is does anyone recognise the type of failure. The inside of the pipe has small craters, almost as if the aluminium has been scooped out. Both the input and output pipe were similarly affected.
The coolant was very clean, I could see no sign of corrosion, in fact the inside was very shiny. Its as if the metal has been eaten away somehow, but in small localised areas.

I know these coolers have a reputation of failing internally and letting oil into the coolant messing up the header tank.

I think it may be cavitation damage since it is very close to the water pump outlet, but I would love to know what you guys think.

Dread to think what would have happened if I had been on the motorway, trashed engine I guess, my advice is next time you change your oil, give the oil cooler hoses a gentle tug and make sure they are ok.

that's is worrying, lucky you found it in time.

I've not seen that kind of damage before - though it's a bit hard to make out on the pictures. I wouldn't have thought cavitation as the pressures aren't really sufficient for that. Tried testing the pH of the coolant?

Regards

Ricahrd

Hi Rodger, i think that the coolant is the culprit. Probably it's not suitable for aluminium: flush it, otherwise it will eat you radiator too...

Fabio/Richard

Thanks for reply. You can imagine that I'm worried that the same thing is happening in the radiator, front/rear heater matrices and anyhing else aluminium in the circuit! That would be a bit of a mess to fix!.

The car is 2.8CRD auto, 2005, 198,000 miles. The coolant was changed by dealer at least once for sure and I think twice in the service schedule. Thermostat was changed Oct 2010 which will have replaced some of the coolant.

I replaced about 6 litres of coolant when I changed the oil cooler, but I will try and find a way of checking the Ph.

I am going to pull some hoses off and have a look inside. I will also try and get some better photos. I think as a precaution I am going to flush and change the coolant.

Thanks again for your response.