Coolant in transmission cooler?

[PE_in_UAE]

When checking the coolant level in my 2015 LR4 SV6, I noticed what appeared to be oil in the coolant reservoir tank. I had the vehicle transported to a workshop to check where the oil could be coming from, thinking oil cooler most likely (as it had recently been changed). The car has a history of losing coolant and the cooling system has been pretty much replaced piece by piece.

The workshop has advised that the transmission needs to be rebuilt as it’s full of water! Is this possible? They’re saying the transmission cooler or a seal to it has failed? They haven’t explained where the oil came from. I haven’t yet seen an itemized quote but would a rebuild be necessary or simply flush, replace seal and move on? Any advice gratefully received.

 

[theegovernor]

Yes it is possible for transmission fluid to get into the coolant via the plate heat exchanger. I would replace the cooler and flush the transmission a couple times before replacing the transmission

 

[greiswig]

Possible if the heat exchanger split or developed a leak. Do you have any kind of feel for how long you’ve been driving it in that condition?

If it were me, after figuring out where the leak occurred and fixing it (e.g. replacing the exchanger), I’d look for shops that could do a genuine flush of the tranny, and do so 2-3 times with some driving between. You might get by without a rebuild.

 

[PE_in_UAE]

Thanks for the responses to my plea for advice! Much appreciated guys.

The workshop is saying that they need to replace the internals (pressure plates, etc) as just flushing won’t last and the transmission will seize within 10 days. I don’t believe this as there were no symptoms when it was taken away. Why would all the internals require replacement? Finding a decent and reputable workshop is the challenge here unfortunately. They tend to just replace all parts whether it’s needed or not, and difficult to know whether it is needed or not. Complicated by the fact we won’t be here much longer anyway.

There is an LR workshop here but I don’t know that they’re any more skilled but they are definitely more expensive!

So replace the transmission cooler and gaskets / seals and flush a few times - seems to be worth a go!