1999 BMW 520i 6cyl leaking coolant

the culture of deference

Hi all.

Mate has 1999 BMW 520i 6cyl leaking coolant. Has no internet so I will be updating him.

Car starts and drives, after 10 miles it starts to overheat and loses 1 or 2 litres of coolant.

Oil cap shows no water traces.

Nissan doctor

...where to start, most coolant fittings are plastic and can leak, expansion bottles can crack, rads can become blocked and leak...

He need to have the cooling system checked properly, i.e, pressure test, sniff test etc

pcardin

Is there any e39 that didnt have overheating problem?

comanche_cor

pcardin wrote: »

Is there any e39 that didnt have overheating problem?

If the car has overheated this may have added to the problem..

This engine is very sensitive to overheating and should not be allowed to overheat. I was advised by my mechanic for (bmw specialist) that if my 2001 e46 320i ever goes above half way on the temp gauge to turn off the engine immediately and call a tow truck ..

langdang

Just saw a fella topping up his 520 on the side of the road from a Ballygowan 5L bottle - looked like it's a regular occurrence and he was well prepared for it!

Nissan doctor

comanche_cor wrote: »

If the car has overheated this may have added to the problem..

This engine is very sensitive to overheating and should not be allowed to overheat. I was advised by my mechanic for (bmw specialist) that if my 2001 e46 320i ever goes above half way on the temp gauge to turn off the engine immediately and call a tow truck ..

Sound advice, You rarely get away without head/headgasket damage if a BM overheats at all.

comanche_cor

langdang wrote: »

Just saw a fella topping up his 520 on the side of the road from a Ballygowan 5L bottle - looked like it's a regular occurrence and he was well prepared for it!

I keep 5L of distilled water in to boot of my e46 - just in case!

Nissan doctor

comanche_cor wrote: »

I keep 5L of distilled water in to boot of my e46 - just in case!

Would it not be wiser to keep 5L of coolant?

comanche_cor

Nissan doctor wrote: »

Would it not be wiser to keep 5L of coolant?

True, though my thinking that if I ever have to use the 5L its going to lose it again so is only a stop gap to get me to where I can stop safely to either sort the problem / call tow truck...

Though I think your logic is sounds, I should just buy 5L of coolant

unkel

If you have a serious leak there's no point in pooring coolant. It won't make any difference compared to putting in tap water. It will just poor out. Once fixed, it should be flushed / filled with coolant of course

pcardin wrote: »

Is there any e39 that didnt have overheating problem?

I think you'll find that every water cooled car will overheat when there is a serious leak in the water and you keep driving the car

BTW had an old high mileage E39 and it never had a water problem / leak / overheat issue...

Nissan doctor

pcardin wrote: »

Is there any e39 that didnt have overheating problem?

Yes, ones that are maintained properly....like all cars IMO.

DublinDilbert

Did any of these have a plastic implellar on the water pump? I know the older ones did. Although i'd doubt it would get 10 miles without over heating if that has failed.

As others have side there's so many plastic fittings on these that can fail, he'll need to have the complete cooling system looked at. Is the internal heater working?

the culture of deference

DublinDilbert wrote: »

Did any of these have a plastic implellar on the water pump? I know the older ones did. Although i'd doubt it would get 10 miles without over heating if that has failed.

As others have side there's so many plastic fittings on these that can fail, he'll need to have the complete cooling system looked at. Is the internal heater working?

Internal heater is blowing cold air.

Will be talking to him later on today to get more info.

Mar4ix

as far as i know, cooling system bleeding is pain in as$ in bmw cars. did it itself start overheat, or after coolant change? when engine is working, you shall see coolant running in radiator. if not, there could be water pump problem, as they are from plastic. if i am not mistaken , to bleed it properly, cars front need to be raised.

Tea 1000

A little side point, but wasn't it late '00 before the 520i became a 2.2 6 cylinder? Weren't the older ones 2.0 4cyl?

unkel

Tea 1000 wrote: »

A little side point, but wasn't it late '00 before the 520i became a 2.2 6 cylinder? Weren't the older ones 2.0 4cyl?

No 520 has always been a straight 6. But there was a change alright from '01 the engine was changed and the size went up from 2l to 2.2l

the culture of deference

Mar4ix wrote: »

as far as i know, cooling system bleeding is pain in as$ in bmw cars. did it itself start overheat, or after coolant change?

he bled the coolant after it overheated

Mar4ix wrote: »

when engine is working, you shall see coolant running in radiator.

he flushed rad, but had cold spots in the rad, bottom hose was cool, top one expanded v hot. no hot air in car.

Mar4ix wrote: »

if not, there could be water pump problem, as they are from plastic. if i am not mistaken , to bleed it properly, cars front need to be raised.

How high?

thermostat was taken out, did a kettle test.

Tea 1000 wrote: »

A little side point, but wasn't it late '00 before the 520i became a 2.2 6 cylinder? Weren't the older ones 2.0 4cyl?

car is a 1998 manual

DublinDilbert wrote: »

Did any of these have a plastic implellar on the water pump? I know the older ones did. Although i'd doubt it would get 10 miles without over heating if that has failed.

As others have side there's so many plastic fittings on these that can fail, he'll need to have the complete cooling system looked at. Is the internal heater working?

this sounds about rught, he gets 10 miles before overheat

unkel wrote: »

No 520 has always been a straight 6. But there was a change alright from '01 the engine was changed and the size went up from 2l to 2.2l

Voodoomelon

You say it looses up to two litres of coolant over 10 miles, surely if its loosing this much after such a short journey you've been able to identify the source of the leak? Have you examined the expansion bottle, hoses and water pump thoroughly? Car only needs to be raised about 12" for bleeding, however air does not sound like its a problem here.

Mar4ix

worth take out water pump, and have a check., no point guess.