Morning chaps,

On Tuesday I finally did the oil-cooler feed pipe O-rings with Viton 611s and, apart from dropping the bolt down the back of the engine, thought all was well. After a good scrub of the oily bits, an undercarriage wash and blast I watched a couple of drips of old oil (I thought) make their way down to the frame and on to my driveway. No big deal.

Last night however I noticed a fair bit more oil on the ground and took everything apart again to look more closely. Everything around the cooler *appears* clean and dry. The pipe is clean and I can't see any obvious signs of oil escaping anywhere.

To add to the horror - I saw 1 single drop of oil floating about in the coolant reservoir. Is it possible that doing the O-rings has somehow increased pressure on the cooler gasket and it's now ready to be done?

I already bought the gasket(s) for the oil cooler, so I suppose that's next on the list. Be honest - how much of a pig of a job is it to do? What would you add to the "while you're in there" list of things to do? I'll replace the still original donut hoses and clean that area out - it would make sense as it's all got to come out anyway. Anything else worth doing?

Thank you all for your posts and help on this amazing forum. It actually makes me look forward to things going wrong!

Sounds like either the gasket or the cooler have a leak if there is oil in the coolant - almost inevitable on these engines. 2012 TDV8 Vogue (L322)

There are 2 coolant fittings where people have found the o-rings perished. 18mmx2.5mm Viton o-ring has been used on the one at the oil cooler and the other appears to have 18 x 3.0 marked on the housing which could be the o-ring size. I've sourced both sizes with the idea to replace both when I investigate the cause of a slow coolant loss. I've already replaced the cooler gaskets.

Thanks - how likely is it for the cooler itself to fail? Can it be tested or inspected in any way without tearing everything apart?

OR - should I just bite the bullet and replace the whole thing to be 100% safe for the future - I want to keep this car long-term and want to get everything sorted properly...

Any offers out there on coolers at present? Part No?

Replace the whole thing. Been known to warp.
Use Advanced Factors. Forum discount code AF4LRP Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
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Last edited by DrRob on 24th Sep 2022 2:19pm. Edited 1 time in total

fmgl322 wrote:

Thanks - how likely is it for the cooler itself to fail? Can it be tested or inspected in any way without tearing everything apart?

OR - should I just bite the bullet and replace the whole thing to be 100% safe for the future - I want to keep this car long-term and want to get everything sorted properly...

Any offers out there on coolers at present? Part No?

Evening all,

I've decided I'm going to replace the oil cooler as a unit and hopefully cure the problem once and for all. Thanks to the magnificent instructions here in the forum, I'm confident that that should fix the drips. As the donut will be off during the swap, I'm going to replace the hoses and clean everything out along the way. Does anyone have a part number for me for the (new design) original LR hoses? Is there anything else you'd suggest doing while I'm in there?

I was digging around under the car the other day and noticed more oil dripping from further back, closer to the gearbox. As the car is parked on a sloping driveway I just assumed that was gravity doing its thing, but when I looked again today I saw there had been quite a bit more dripping down. The car has not been out in the last 48 hours. Is there something further back that could be causing a leak like that, or could it just be accumulated oil spread back there during trips? As far as I can tell, it's engine oil. I hope it's gearbox oil leaking out - I have NO idea when or if the gearbox has ever been serviced (it's on the list of things to get done externally), but it's doing its job perfectly, so I don't suspect there's anything wrong there.

What do you think? Am I now being paranoid about oil leaks (yep, they're even appearing in my dreams!), or is this all just part and parcel of 10-year-old RR motoring?

Thanks and more anon... -------------------------
2012 4.4 TDV8 Vogue
2001 Audi A2 1.4 16V
2019 Skoda Kodiaq (don't ask...)

Save yourself some money and just get some 70mm hose.

Otherwise 4 small hoses will cost you £170. 2015 Range Rover Autobiography 4.4 SDV8

GraemeS wrote:

There are 2 coolant fittings where people have found the o-rings perished. 18mmx2.5mm Viton o-ring has been used on the one at the oil cooler and the other appears to have 18 x 3.0 marked on the housing which could be the o-ring size. I've sourced both sizes with the idea to replace both when I investigate the cause of a slow coolant loss. I've already replaced the cooler gaskets.

It's closer towards the front of the engine.