Finally got the coolant hose done and took the RR for a test drive. There wasnt a big puddle underneath like there had been previously but still a strong smell of hot oil.

What degreasing products would anyone recommend to try and remove the oil from the back of the engine, V valley and underside?

Mine kept smoking for a few trips. The oil collects in the V of the block and slowly trickles down. Just wait a couple of weeks and it will be gone. I went round a really sharp bend and got traction control kicking in, then 10 mins later smoke pouring out!! I thought a seal had failed but it was just more oil coming out of the V. It's not easy access to use degreaser. Time will do it better. 2012 L322 4.4 TDV8
2001 P38 2.5 BMW

Many thanks to mm289 and others for vital info that enabled me to (almost) sort out my oil cooler / O ring leak. Brilliant.

I say almost because, having carefully completed the job and started the engine AOK with a smug smile, I thought I'd just have a quick check under the engine as it was warming up to ensure all was well, and my bubble was burst on seeing coolant dripping through....

Turns out it is coming from the click connector coolant pipe that connects onto the oil cooler, as in the photos below. It hadn't formed a proper seal and was leaking (and I suspect might have caused a previous slow coolant leak). I removed the seal within the connector which was perished on one side (additional pic). It looks like an 18mm internal diameter seal, and is slightly flattened and a bit more like a seal than an O ring (though maybe because it's been squashed?). Does anyone know what the spec is, or where I can get one?? Would an O ring work?

I've searched online for the connector and can only find links to bulk buy in the US. Thanks, Matt

At least it's not an oil leak!! I was suspicious of that connector when I did mine. Seamed to connect too easily and I couldn't feel any O ring or something slide over the male part. Seemed to form a seal tho! 2012 L322 4.4 TDV8
2001 P38 2.5 BMW

Years ago I bought a selection box of O rings off ebay and have used them numerous times on various cars for such occasions. Might be worth a try.

Thanks Alan and Kevin. Yes it clicked on perfectly - I guess as little resistance. It was dripping out quite fast once engine running. I've a feeling it's the top of the three-way EGR cooling pipe?? Anyone changed one?

The T-piece with its 3 hoses is LR022718. I'd be looking for a suitable o-ring.

Many thanks for the confirmation Graeme. Have ordered both...

Found this surprise .....
And this time it was not the o-rings .....

Click image to enlarge

Well done on the repair. Very strange having the bolts shear, especially when there's a rubber gasket below. 2012 L322 4.4 TDV8
2001 P38 2.5 BMW

That was our "thinking" as well ....
And after the third we changed to new ones. RR Vogue, 4.4 TDV8, 10/2010, Santorini Black
(EGR out, 380HP, 800Nm)

Pretty sure I have now sorted the oil cooler leak - many thanks to wisdom imparted on here which made it possible.

After doing the repair I had a dripping coolant leak from the click connector which attaches to the cooler as below (I think this is the EGR cooler hose). Inside this connector is an O ring - which I have since discovered is a 2.5 x 18mm ring, available from simply bearings for buttons. I don't know what the correct material should be so I got both EPDM and Viton rings, but both seem about right, with EPDM feeling a bit more soft like the existing ring. In any case, I ordered the complete EGR cooler T-piece hose (Part LR022718) for only ~£25 and took the O ring out of that to fit to my existing T-piece. It's stopped leaking now.

I was losing coolant before doing the oil cooler fix and suspect this to be the culprit as the existing O ring was perished. It might therefore be worth also changing this O ring anyway if you have the manifold plenum off to sort the oil cooler. It is just about visible to check for leaks without removing the manifold by looking with a good torch from the front right of the car.

That o-ring is cooked like the cooler gaskets and the o-rings on the turbo oil feed pipe, so I'd keep the Viton ones with spare oil feed pipe o-rings where they'll be found when next needed. Thanks for the sizing - I'll procure a couple for when mine fails.

A bit of advice and guidance please:

So, I have just had a service on my 4.4 TDV8 and the start of an oil leak from the oil cooler has been identified. I have been quoted £967 for parts & labour for supply & fit of a new cooler

Does changing the O ring cure the problem in most cases?
How long should it take to change it cost the o ring at an independent, how much should it cost?
Can anyone recommend and independent for the job Northamptonshire or Leicestershire preferred, or Cambs, Lincolnshire at a push.

There's 2 types of oil leak from the cooler. 1 from the O rings as you mentioned, then also a gasket (2 gaskets) failure on the cooler itself. If you go to the top of this topic and follow the comments you will be able to find where to look to see if it's the O ring at the back. If it's O rings, it's a 20 minute job. 2012 L322 4.4 TDV8
2001 P38 2.5 BMW