Oil Cooler!

[Ralph1Malph]

Hello All,
Well, a trip to the Indy has seen my leaks diagnosed.
Leaky engine coolant connector assy (replaced only 4yrs ago, but leaking from the rear connection); and leaking oil cooler assy.
I did prioritise the coolant connector assy, but now notice oily residue in the coolant overflow bottle.

I've searched and read, and read and searched the interwebs, but can't get a definitive explanation regards how the oil gets into the coolant.
I understand the external leaks through the mating surface gasket, thus filling the valley, but can only assume the coolant galleries inside the assy corrode or fail and allow oil into the coolant?

I'm keen to understand this as it means the difference between changing the gasket ($50) or the whole assy ($500)!

I'm compiling a parts list and am going to buy from England coz I'm able to let her sit, unused in the meantime.

List so far:
Gasket,
Coolant connector assy,
Overflow bottle,
Bottle cap.

I'm going to do all this myself, with time I don't have, but I have more time than money!

Whilst I've got it all apart, is there anything else I should do?

Cheers
Ralph

[loanrangie]

Touch wood no leaks thus far but have you had the belts done ?, cheap from the UK if you need the kit or any suspension bushes, compressor service kit etc.

[Ralph1Malph]

Touch wood no leaks thus far but have you had the belts done ?, cheap from the UK if you need the kit or any suspension bushes, compressor service kit etc.

Belts ok due to HPFP replacement 4 yrs ago. I will order a bunch of sway bar and track rod bushes tho!

[PerthDisco]

There’s an o-ring for the oil cooler to coolant assembly connection you need to order separately and replace at same time. This becomes very hard after time. Worth doing the o-rings on the intake manifold also.

[shanegtr]

I've searched and read, and read and searched the interwebs, but can't get a definitive explanation regards how the oil gets into the coolant.
I understand the external leaks through the mating surface gasket, thus filling the valley, but can only assume the coolant galleries inside the assy corrode or fail and allow oil into the coolant?


It would be an internal leak between the oil and coolant galleries. Since the oil is generally under higher pressure than coolant the oil will generally leak in that way. Ive had a successful detection of coolant into the oil from the oil cooler through oil analysis earlier this year

[Ralph1Malph]

It would be an internal leak between the oil and coolant galleries. Since the oil is generally under higher pressure than coolant the oil will generally leak in that way. Ive had a successful detection of coolant into the oil from the oil cooler through oil analysis earlier this year

Yes, I suspected that! A new oil cooler is the order of the day then!

[DiscoJeffster]

Yes, I suspected that! A new oil cooler is the order of the day then!

I stripped mine down after removal. Yes they break down internally as the seals give way.

[Eric SDV6SE]

It would be an internal leak between the oil and coolant galleries. Since the oil is generally under higher pressure than coolant the oil will generally leak in that way. Ive had a successful detection of coolant into the oil from the oil cooler through oil analysis earlier this year

Makes sense to me, as if it was the other way around, coolant in oil would be a far worse problem.

Nearly 12years on and no issues, but don't want to temp lady fate too much. Keeping an eagle out on the oil cooler and coolant system for any signs.

[shanegtr]

Makes sense to me, as if it was the other way around, coolant in oil would be a far worse problem.

Nearly 12years on and no issues, but don't want to temp lady fate too much. Keeping an eagle out on the oil cooler and coolant system for any signs.
Still have the potential for it to go the other way around - when you shut off the engine you'll now have zero oil pressure but still pressure in the coolant system

[LukeD4]

Hi team, new here.

I have just purchased a 300,000 km D4 TDV6 MY10 i only paid 13g for it and its in pretty good nic with a long service history $9500 receipt at 256,000 ks etc.

Any way i took it to my Indi close by and the only thing he could pick up was the fact the coolant bottle had a dark tinge and that there was water in there not coolant, he done all the usual checks for head gasket etc and all seems well so he thought maybe an egr cooler had been leaking exhaust into the cooling system as there was slight contamination.

Ive drained the cooling system and what came out was clear clean water but with some what on an oil slick and oil residue in it. as the water poured out it was clear but only in the bucket you could see the oil.

Now im thinking its more oil cooler than egr coolers, there are no other signs or symptoms of anything and it seems this is the same as whats going on here.

No water in my oil or anything like that either.

Thoughts?

[PerthDisco]

100% guaranteed the oil cooler causes this issue around 10 years or 250k kms. It also leads to the valley filling with oil which will leak down the back of the engine. Change the coolant bottle at the same time.

I had exactly the same issue as have others with an oily high tide mark in the bottle. I need to change my coolant again to make sure I got all the oily stuff out as it is now a darker pink than it should be although the new bottle does not have the tide mark it did before.

I’m not convinced I don’t also have an EGR cooler issue which is more difficult to resolve. Easiest way for 2.7D would be to bridge the coolant lines and leave coolers as is with EGRs blanked.

[DiscoJeffster]

My bottle had the black gunk in it when I recently did a coolant change. I’ve had the oil cooler changed. While there was a little bit of an oily tinge to the coolant, it was the more soot like black stuff that caught my eye. I’ve since changed the coolant and bottle and will see what comes of it.

I suspect EGR coolers in my case but I don’t fancy the cost to change them out, and I don’t think you can blank the 3L even with a tune as I recall it needs functioning EGR to test against. I also read the so called emulators weren’t much cop.

[Tombie]

My bottle had the black gunk in it when I recently did a coolant change. I’ve had the oil cooler changed. While there was a little bit of an oily tinge to the coolant, it was the more soot like black stuff that caught my eye. I’ve since changed the coolant and bottle and will see what comes of it.

I suspect EGR coolers in my case but I don’t fancy the cost to change them out, and I don’t think you can blank the 3L even with a tune as I recall it needs functioning EGR to test against. I also read the so called emulators weren’t much cop.

You need to talk to Cambo from Old Jaguar

[DiscoJeffster]

Looking at the britpart EGR replacement video I note the valve is separate to the EGR cooler. As the valves work, might be able to simply replace the coolers - though simply is never a word that can be used in that area of the engine, or on a Disco [emoji4]

[DiscoJeffster]

Ok. So the cooler alone is around $600 per side from Rimmerbros. Ouch

And edit: only applies to the 2.7L.

[PerthDisco]

Ok. So the cooler alone is around $600 per side from Rimmerbros. Ouch

And edit: only applies to the 2.7L.

They pop up regularly on eBay from trashed engines worth a look if from a low km engine. Only a simple shell & tube cooler.