e39 overheating - overhaul cooling system?

[tonylauno1 7]

Driving on the highway for 90mins; got home switch the car off for 30mins before going out again. 3kms later in the city, white smoke was blowing from under the hood. Car had overheated.

Managed to tow the car back home myself, hope my mechanic is working on 31st Dec.

Now I am thinking it could be those plastic propeller on the waterpump or the thermostat has broken which both looks like it's quite difficult to access. There are some people who says this is just the beginning of a series of trouble which I would encountered if the cooling system is not overhaul? - What are your thoughts and experience?

Thanks again to everyone who has replied to my various topics and to the people who have created bimmersport.co.nz & keeped it alive.

Edited December 30, 2007 by tonylauno1

[greenday-rulz21 4]

Is it leaking or been leaking any coolant?

Smoke or steam?

Edited December 30, 2007 by Nick021

[tonylauno1 7]

No leaks what so ever, just some coming from the reservoir when it over-heated and water level is just right too.

It is steam coming from the bonnet not smoke; wrong word, my bad.

[Yuen 16]

When the water pump on my E36 broke, it leaked. Seems to be the case with some others I've seen. On first thought it sounds like a thermostat stuck closed, just from the car going 3km before overheating, but it should have still been pretty hot since you only turned it off for 30 mins. I'm not sure if that cooled it down enough for the thermostat to close...

Any unusual noises? How many KMs has the car done? What year is it?

As for the water pump impeller breaking - on the E36 they started off with a plastic impeller that got brittle through time, they then went to a metal one and later on, a composite one which is the best. I'm thinking no E39s should have gotten the plastic type since the first ones came out in 1996?

On the E36s the cooling system is usually changed as preventive maintenance, I would do it around 100,000km. I would think the same applies to other BMWs.

[tonylauno1 7]

When the water pump on my E36 broke, it leaked. Seems to be the case with some others I've seen. On first thought it sounds like a thermostat stuck closed, just from the car going 3km before overheating, but it should have still been pretty hot since you only turned it off for 30 mins. I'm not sure if that cooled it down enough for the thermostat to close...

Any unusual noises? How many KMs has the car done? What year is it?

As for the water pump impeller breaking - on the E36 they started off with a plastic impeller that got brittle through time, they then went to a metal one and later on, a composite one which is the best. I'm thinking no E39s should have gotten the plastic type since the first ones came out in 1996?

On the E36s the cooling system is usually changed as preventive maintenance, I would do it around 100,000km. I would think the same applies to other BMWs.

What I meant to say was driving on the highway for 90mins was fine then I went out again 30mins after I got home. 3km later of city driving the car overheated, the only warning I had was "check coolant temperate" - by this time it was too late. No noise, nothing unusual.

An old waterpump which has had it will leak, I thought if the propeller broke on a good waterpump it wouldn't leak.

The car is a 97 with 125,000km - I have changed the fan belt and tensioner a year ago. So you change the entire cooling system on your e36, how much did that set you back?

Edited December 30, 2007 by tonylauno1

[Yuen 16]

Hmm, yeah I'm not too sure about the waterpump bit, just stating from my own experience so probably shouldn't generalise.

Not sure where my receipts are so I will give you a rough estimate off the top of my head, going with brand new, OEM parts (Behr, Lemforder etc):

Radiator - $500

Water pump - $200

Fan - $100

Fan clutch - $250

Hoses - $100+

Expansion tank - $100

Fan and fan clutch should be fine unchanged unless you have issues. So I guess budget for at least $1k in parts. As for labour, I did the work myself but it will take a few hours for a shop.

Edit: With the year and KMs of the car, I think a cooling system overhaul is in order anyway so this is a good time to get it done - unless the E39 system lasts longer than an E36's.

Edited December 31, 2007 by Yuen

[tonylauno1 7]

Well, it is actually the thermostat housing which cracked.

The mechanic said the waterpump (plastic impeller) and thermostat looked quite new therefore did not need to change and that the cooling system is running at 9.4psi which should really be 9.0psi according to manufacture's specification but it's not a problem, will recheck in next service.

The Honda, Mercedes-Benz, Volvo's that I have seen all uses metal thermostat housing. The mechanic said metal housing were available and it cost twice as much + it would take a few weeks to get it from USA so I settle for the normal plastic ones as I wasn't prepared for the long wait.

[Yuen 16]

Good to hear you've got it sorted. Forgotten about the whole thermostat housing issue - my E36 had a metal one being an early model. People like to change the thermostat housing to the metal one as part of preventive maintenance, so if you do overhaul your cooling system next time you might want to do that. How much did the plastic one cost you?

[tonylauno1 7]

Good to hear you've got it sorted. Forgotten about the whole thermostat housing issue - my E36 had a metal one being an early model. People like to change the thermostat housing to the metal one as part of preventive maintenance, so if you do overhaul your cooling system next time you might want to do that. How much did the plastic one cost you?

The housing cost $228 and it was fixed on the same day- might sound cheap but add $305 labour + other stuff & GST = $620. Wasn't prepared to wait 5 weeks for the metal one which cost $400+.

[allan 295]

Interesting read this may help if you decide to do the cooling system over haul at some stage

http://www.bimmerboard.com/forums/posts/199986. Have fun

Or if you really love your E39 give it the Rolls Royce treatment

http://www.zionsvilleautosport.com/store/s...tegory_Code=CCS

Cheer Allan

[kiwi535 538]

Interesting read this may help if you decide to do the cooling system over haul at some stage

http://www.bimmerboard.com/forums/posts/199986. Have fun

Or if you really love your E39 give it the Rolls Royce treatment

http://www.zionsvilleautosport.com/store/s...tegory_Code=CCS

Cheer Allan

those ZA radiators look sexy....theywould have to become part of the car cleaning routine ,they look so good!Does the E39 have the viscous clutch on the fan as standard,and the electric fan replace that....or is the e 39 fan electric from new?