E39 540i Coolant Leak

[martin mrt]

Good evening, im hoping someone can help me with the above issue, before i go and see the car, and whether its worthwhile buying it,

Basically its a 540i with a waterleak apparently at the back of the engine somewhere, now my memory may be hazy here but im sure this is not a straightofrward fix,

and BMW experts shed some light on this?

Cheers

[Magog]

I'm no expert either I'm afraid, but isn't this one of the most common failure on E39's, something to do with brittle hoses or suchlike (thouh this might be the 6 cylinder models, or I might be talking rubbish).

[martin mrt]

I'm not too sure, I had read about some pipe that runs between the two banks of cylinders on the E65 7 series V8s has been known to leak so i'm just hoping this is not the case

But now you mention it that hose theory does ring a bell, but like you I'm not sure if this is confined to 6 cylinder models or if it affects the V8 too

[eliot]

martin mrt said:

I'm not too sure, I had read about some pipe that runs between the two banks of cylinders on the E65 7 series V8s has been known to leak so i'm just hoping this is not the case

Thats correct - do a little googling for coolant leaks and you should get info / photos on where to look. There is a valley pan that corrodes and also o-rings on the coolant pipes at the back that go.
The cooling system on the V8's is pretty crap once they are up to about 100k miles. Best thing is to replace everthing in one sitting and you will end up with a reliable car again.
So change the radiator, water pump, thermostat, hoses and the o-rings on the pipes.

[peaktorque]

eliot said:

martin mrt said:

I'm not too sure, I had read about some pipe that runs between the two banks of cylinders on the E65 7 series V8s has been known to leak so i'm just hoping this is not the case

Thats correct - do a little googling for coolant leaks and you should get info / photos on where to look. There is a valley pan that corrodes and also o-rings on the coolant pipes at the back that go.
The cooling system on the V8's is pretty crap once they are up to about 100k miles. Best thing is to replace everthing in one sitting and you will end up with a reliable car again.
So change the radiator, water pump, thermostat, hoses and the o-rings on the pipes.

BMW made all of their cooling circuit from very brittle and expensive to replace 'plastic'. Renew it all because it will all fail.

The latest part of my cooling circuit to expire (@ 160,000) is the manifold that sits on top of the gearbox heat exchanger. £70 to replace, but guess what, BMW have none available until the end of july.

Utter crap.

(still love the car though)

Edited by peaktorque on Sunday 13th June 21:12

[papercup]

martin mrt said:

Good evening, im hoping someone can help me with the above issue, before i go and see the car, and whether its worthwhile buying it,

Basically its a 540i with a waterleak apparently at the back of the engine somewhere, now my memory may be hazy here but im sure this is not a straightofrward fix,

and BMW experts shed some light on this?

Cheers

Its a very simple fix if its what happened to mine, whioch is very common. Its the pipes from the back of the engine to the heater matrix. Only about 8 inches long from memory.

Mine was losing water over time and in the end it got silly, like a litre a day. Then it just split completely and left me stranded. I called the AA and its so common with the 540 even the AA guy knew which one it was. Take the engine cover off and you can see it down the back, though you need slim arms to get to it. He bodged it and I ordered a new one the next day. It was about £20!