E39 540 leak

[fitzgeraldn]

Hi everyone,

I am the proud owner of the worlds most unreliable 540 and was hoping some kind people on here may be able to help me identify a leak. My car is setting of on a 6 hour journey tomorrow!

My car is leaving a puddle of bluish fluid everywhere it goes, however seems to be driving fine and temperature stays bang in the middle and no dash warnings. I have attached a picture of what it looks like on a cardboard box. I have checked the expansion tank and my coolant appears to be red, although can't be certain.

cheers guys

[Eddieslofart]

If it’s near the drivers side wheel well, it will be the washer bottle. Well known for splitting.

Does the fluid smell similiar to washer bottle fluid ?

[fitzgeraldn]

It doesn't seem to really smell of anything, it is leaking out of a hole I have in my engine under tray, I have had a look at the washer fluid plastic thing and cant see any fluid in it though which is suspicious

[rsbmw]

Blue fluid on floor. Empty washer bottle. Hmm.

Could it be petrol?

[fitzgeraldn]

lol

[fitzgeraldn]

lol

[d_a_n1979]

More than likely the intense washer bottle or the main washer bottle

They both go brittle and crack with age; their filters can get blocked too and cause them to leak from the pump seals etc

If it hardly smells of anything and isn't oily; then IMO it points to the washer system

However; be over-cautious and take 2l of pre-mixed washer fluid with you and the same with coolant/water, just in case...

[fitzgeraldn]

Thanks for the replies guys- we have an update though- my coolant is blue, just tested it. Even more worryingly could see the below in my engine bay- is this a coolant leak? would you drive with this?

[fitzgeraldn]

If you interested- this is what my expansion tank level looks like

[d_a_n1979]

Ah, there you go then

That float should be level with the top of the open neck when the engines cold

If it’s sat at the bottom then the coolants low.

Top it up; get the engine up to temp and see where it’s leaking from. The cooling systems on these cars are chocolate based at best, so they need good maintenance.

The header tanks can crack, so check that. The feed from the top hose side back to the header tank can leak too, check that especially the elbow on the top hose corner

The rads can crack too; top hose corner again and sometimes next to the header tank

I wouldn’t risk any journey in the car until that leaks fixed.. Fingers crossed it’s just something simple like the header tank cracking

It all needs a good look over

[d_a_n1979]

Get yourself on the 5 forums too pal: http://forum.bmw5.co.uk/

A wealth of knowledge on there and a specific E39 tech section

[iSore]

fitzgeraldn said:

Hi everyone,

I am the proud owner of the worlds most unreliable 540

There will be a few challengers to that throne.

[sparks_E46]

It’s not going on that 6 hour journey.

[fitzgeraldn]

Hi chaps, wanted to thank you for your help, pistonheads stopped letting new members post for a short while though. Took your advice and went on journey in different car in the end. Will get car over to Birds BMW (local garage) asap and probably get whole cooling system looked / replaced. Any idea what this might cost (inc labour) ? not feeling very rich at the moment but want a reliable car.

[sparks_E46]

fitzgeraldn said:

Hi chaps, wanted to thank you for your help, pistonheads stopped letting new members post for a short while though. Took your advice and went on journey in different car in the end. Will get car over to Birds BMW (local garage) asap and probably get whole cooling system looked / replaced. Any idea what this might cost (inc labour) ? not feeling very rich at the moment but want a reliable car.

£600ish if using genuine parts. Well worth the outlay.

[d_a_n1979]

Hell of a lot more if using genuine BMW parts, £600 is cheap!

I’d personally buy my own parts via decent resellers on eBay using RealOEM for the part numbers and get a decent local Indy to do the work for you

I’d go:

Meyle water pump
Behr or Nissens radiator
Walher stat
Febi/Meyle top & bottom hoses

The resellers on eBay I use and would always recommend are C3BMW & BMWmotormec

A lot of use on the BMW 5 forums use these folk and they’re very good

[iSore]

fitzgeraldn said:

Birds BMW............. not feeling very rich at the moment

Oh dear.

Any decent regular garage can fix that. First job is a pressure test to locate the leak, then replace what's gone. Trouble with these things is that they run very hot for emissions (well over 110 degrees) and the cooling system is under massive pressure. Depending on what year it is, the fix is to use either an E38 740d stat or one from an Arab market 840Ci. That lets the poor thing run about 15-20 degrees cooler.
E39's also run damped temp gauges - the needle being in the centre still means it's running bd hot. By the time the needle starts creeping up, your engine is about to do a Krakatoa.

I wouldn't spend £600 on it myself. They're just a ticking bomb.

Edited by iSore on Sunday 7th October 14:35

[sparks_E46]

iSore said:

fitzgeraldn said:

Birds BMW............. not feeling very rich at the moment

Oh dear.

Any decent regular garage can fix that. First job is a pressure test to locate the leak, then replace what's gone. Trouble with these things is that they run very hot for emissions (well over 110 degrees) and the cooling system is under massive pressure. Depending on what year it is, the fix is to use either an E38 740d stat or one from an Arab market 840Ci. That lets the poor thing run about 15-20 degrees cooler.
E39's also run damped temp gauges - the needle being in the centre still means it's running bd hot. By the time the needle starts creeping up, your engine is about to do a Krakatoa.

I wouldn't spend £600 on it myself. They're just a ticking bomb.

Edited by iSore on Sunday 7th October 14:35

My 530i overheated and it was fine, I did switch it off when I noticed the gauge approaching the red. When I said genuine parts I mean from C3BMW and the like. OEM is what I should of said, same parts without the BMW badge. Worth spending the money if it’s a goodun, the cooling system and auto box are the only weak points.

[iSore]

And the chain tensioner guides. Never underestimate the E39 V8's ability to throw you an enormous bill.

[fitzgeraldn]

Thanks for the advise, going to give the whole cooling system an overhaul. I feel it is probably worth the money as have sunk around £4K into this car over the last few months already (electrical issues etc) Hope timing chain guides won't give out yet as replaced the tensioner and car only has 66k on the clock. Boy old BMW's are money pits though- have you chaps had similar experiences?