2.7 TDV6, a wee bit of a problem, possibly......

HI Ean,
I agree, I got mixed up for a moment, I thought Caver meant the housing under the Y piece.

Hi Ean,
Sorry, Auto, missed that bit.............

Thermostat housing is plastic and when mine leaked the coolant travelled to the back of the engine. Conensation could be seen on top of the air inlet and throttle body.

There are several hose connections around there. Oil cooler amongst others.

Hi Forumites,
Progress so far..........got the "procedure" from Ean and proceeded to strip things out. Got the air box elbow off, disconnected al the wiring, released the EGR clips, removed the bolt that secures the intake air shutoff throttle, all good so far...... oh and released the fuel return line valve.
Removed the AST and now I've found traces of red "juice" underneath where the join is in the water outlet housing. Took some pix from inside the inlet manifold, looks a bit grubby, and only done 115k....... amazing. I've included a couple of pix for you to look at.
Now to remove the water outlet housing........... a job for next weekend..........business calls..

Based on what I've found now and the two D3's I've had before I reckon this could be quite a common problem. On my last D3 I had a distinct hot coolant smell but could never find a leak, I used maybe a half a litre between services.
I'm going to assume that if this outlet housing has a very slight leak, more so when under load the slight drip will leak into the engine valley and due to the temperature of the engine the water will flash off creating this smell of hot coolant. Only when the leak gets big enough to fill up the valley and leak out at the back of the engine would you be any the wiser.
Thats my theory and I'm sticking to it. I test drove at least three other D3's when purchasing the one I used to own and two of them had low coolant levels and no signs of water leakage, the owners just told me it was normal and they topped up every month or so.
Something to be aware of, my Range rover drove around for a week or so and never lost a drop, went up into the hills for a lunch and lo and behold the old girl used about 500ml, now I know where it went to and that the capacity of the engine valley is around 500 ml.
Hope you get something from my findings.

Will have a look at the workshop manual and see , but would expect there to be some o-rings in that housing, likely to warp abit as it only looks like plastic.

Thanks for the update.

Cheers Ean

I think that is the thermostat housing. Exactly as you say is plastic warps and leaks then will eventually fail. Common issue on many modern engines.

Inlet is normal for a car with EGRs. If it <MY07 you can blank them off. If older you will get a fault message.
Make sure your map sensor is clean that gunk can block it up.

Hi CaverD3,
This apparently is the referred to as the outlet housing, the thermostat housing is on the bottom left hand side of the radiator, accessible from the nearside wheel arch, the new one I've bought hasn't got a thermostat in it (thank you Sneigy). Also Ean the split in the housing is a moulded split there isn't an o-ring and this joint can't be separated without wrecking the housing, it can't be repaired so the outlet housing now is basically scrap. When I get the housing out I'm going to cut it up to have a look at the failure mechanism.
I'll post the results.

That explains the confusion. That is the bit that failed on mine, was told it was the thermostat housing.
The description in the bill says 'leaking from thermstat housing'. But the part is listed as RO1357091 outlet-water.