Hi, I have a steady drip of coolant seeping from the joint between the transfer case and auto gearbox (see photo).

There's no pressure in the system as the car had been in the garage for about 9 months on axle stands while I'm refurbing the suspension and subframe with little free time.

I can't find any clear info in the Haynes manual to help work out where the leak might actually be coming from in there - really hoping someone can shed some light on possible sources before I have to pull big bits off just to investigate!

Thanks very much!

Photo now uploaded - sorry

Just trying to think about what is above that area for it to leak from :
May be :

thermostat?
associated pipework?

Look at page 938 onwards in the JLR workshop manual (free to download - just search for it) Jules

Thanks, jules - I suspect you're right about it coming from above. I'd sort of ruled that out because it's definitely coming out of the drain hole between the casings rather than round the outside and I can't see any wet areas above.

But that's the key thing - I can't really see that area well at all. I'm surprised but I'm coming to the conclusion it's somehow leaking into the casing joint from the top and out again at the bottom without spilling anywhere else. I'll take the battery and air filter housing off to have a good look around as nothing else makes much sense - and at least it's an easy start!

Thanks again for the reply.

AFAIK no coolant crosses between engine and transmission within the casings. So it has to be coming from outside somewhere. If it was the other end of the engine I'd suggest water pump leak.

Clutching at straws:

Could it be coming from the radiator/transmission cooler and blowing on to the engine/gearbox ?

What about the oil cooler - at the front of the engine but coolant might be blown around the engine Jules

Thanks - yes, it was my understanding that there shouldn't be any engine coolant passing inside those casings.

Still unsure exactly how it's getting into that joint without appearing elsewhere but I'm pretty sure now that it's coming from the thermostat housing above. I can see that's leaking significantly, now that I've got to it, but I'm going to have to remove it to find out exactly where from (waiting for replacement part).

Thanks again for your advice.

Hi!

Any news?! I've got the same problem, same place!?

I tought it could be the water pump?
My calorstat is new, the radiator too...
Thank's!

Hi Al3x,

It was coming from the at least one of the joints on the thermostat housing, in my case - it was hard to see but became really obvious once I removed the air box. I seem to recall that the shape of the casting was allowing the coolant to pool in such a way that it found a way 'into' the casing joint.

I should say that there are loads of places where disturbed hoses can leak on that housing - and some have internal O-rings. Unless you've replaced every part, it's quite likely that it will have a weep from somewhere and coolant is very searching of small gaps. I gave up chasing it after a while and threw in a bottle of Radweld!

On the 2.2 Ford diesel engine, the water pump is on the other side of the block, driven by the cambelt.

I had a leak coming from the Thermostat joint. It showed as a small pool of coolant on the autobox top.

The stat is plastic with a rubber seal and bolts on to the ally engine. I just removed the stat cleaned the faces, put a new rubber gasket on, put a smear of silicone sealer on the rubber seal. That cured it. 14,000miles later no problems

My thermostat is brand new 😵‍💫
I will Check it once again

Thanks for the advices !

My engine is the 3.2 I6

But does a new thermostat come with a new gasket or could the old gasket have been used again ? Jules

I don't have experience with the 3.2 but, on the 2.2 diesel, there are soooo many places it can leak from, and not all of the o-rings that need replacing are on the housing itself - so it could end up with a lot of parts needing renewal and then chasing more disturbed-and-now-won't-reseal joints further back through the cooling system. All expensive dealer-only parts. Hence my very reluctant surrender to Radweld after swapping the housing and the o-rings I could replace myself. I kinda miss Jubilee clips!

the thermostat i've change was brand new, with new seal...it's not complicated has the diesel engine, no special O'ring on it etc...

Yesterday evening I had a look by night with a special UV light that make coolant really visible, I'haven't look leak near to the thermostat

Some news !

I've worked on my beauty today (I'm the owner since may 2023), seems to be the water pump !
I will change the belt and pulley has well, will be nice for this poor car, 12 YO end 240.000Km/150000Mi still the origines parts on it !!

Click image to enlarge