Hi all, as mentioned above I have a lot of oil in my coolant reservoir - no sign of coolant in the oil though. Reservoir seems to over pressure as well and start leaking. Symptoms include coolant temperature gauge dancing all over, sometimes going up to 120 momentarily but usually staying around 90. My colleague suspected head gasket, I was cynical due to no coolant mixing in with oil in the sump - compression test shows normal readings. I personally felt that the oil cooler below the filter had probably failed, after attempting to remove it from the topside I came across a pretty poorly located bolt at the bottom of it that I couldn’t access and had to end up stripping the whole front end off and rad off (needed flushing anyway) and removed the oil cooler. When it was off it SEEMED like the o rings on the oil side of it had failed and there were traces of oil inside the coolant ports, plus traces of oil on the face of the cooler,  and the o rings looked rough, so I am happy I replaced it even though it was a pretty ridiculous task. 
 

Here comes my actual question - there seems to be I believe a water cooled intercooler, two coolant pipes to the bottom and one large boost pipe. I can’t find this part new ANYWHERE even euros struggled to find it. When I removed the coolant pipes to this they were really thick with oil. Anyone had similar issues with either of these two parts and the symptoms I suggested earlier? I really don’t want to overlook something simple whilst the whole front end is removed. Anything I should replace whilst I’m here that I haven’t thought of that could be damaged? Obviously flushing all coolant system, oil change and filter, etc. hopefully not looking to replace water pump/gaskets as that’ll be coming up soonish anyway. Thanks for reading.

Thanks

 

edit: to add, this is one of my own personal vehicles that I recently bought. Not much history. 

Edited September 28, 2025Sep 28 by HGVTechToy
More info

Hi,

The intercooler on the 1.6 TDCi is not water-cooled.

Perhaps you are looking at the EGR cooler?

A picture would be ideal here.