E39 530d losing coolant

[Matt_N]

Morning folks.

The old man's 530d has started using or losing a bit of coolant over the last few days.

I know the cooling system can get a bit tired with age, his is a Y with about 110k on it, it's an auto too.

He drove from Chester to York and back again yesterday with the low coolant warning coming on, he has topped it up with around half a pint to bring it back to the level.

I'm in Bristol and he is in Chester, but he is coming down here later this avo, so I can check a few things.

Are there any common parts that break down over time - thermostat housing, hoses, rad cap etc or is it likely to be HGF?

He is going to try and get it down to his indy this morning to give it a check over aswel.

Cheers.

[Vee]

Check the black header tank. Prone to cracking.
Also waterpump leaks.

[BliarOut]

Probably the side of the rad... If it is I'd replace the water pump while it's out then she should be good for another few years. The plastic used age hardens

[john_p]

Does the E39 have the heat exchanger where ATF is cooled by the coolant?
If you see oily deposits in the coolant, but nothing in the engine oil, I'd suspect failure of that.

[anonymous-user]

check for weeping from the top hose outlet stub mounting in a hard to see location under the intake manifold. It's plastic, and can distort with age an weep a bit. coolant tends to run forwards and backwards along a block stiffening rib directly under the housing, and hence disguse where the source of the leak actually is.

[Matt_N]

Turns out there is a small leak coming from the oil cooler.

Radweld has kept it water tight for the time being, a replacement is being priced up by his local garage.

Cheers.