E39 523i OVERHEATING PROBLEMS, ALTHOUGH STILL WARM AIR HTRS

[carl24]

does anyone know what the problem is, theres still warm air coming out of the heaters but the temp gauge is in the red, ive bought a new thermostat but i havent a clue where it goes as its my first car

[eliot]

Maybe your thermostat is stuck closed, which would cause it to overheat. Your heating would stay warm because the water is drawn from the engine not the radiator.
Thermostat is behind the item numbered 4 on here:
http://www.realoem.com/bmw/showparts.do?model=DM32...

[Mr Green]

Don't drive it in this condition if you do the head gasket will blow. What's the milage and has the water pump been changed? A water pump costs about £30/40 and £60+ to have it fitted.
Sometimes when a car over heats and blows the head gasket people just change the gasket only for it to blow again because the water pump needs changing, on an E34 they recomend it at about 95k, it's probably the same for an E39.

[carl24]

hi, the car has done just over 140k and has full service history and it was done at 132k, although i have a load of receipts for parts none show its had a water pump

[eliot]

I would do the pump and thermostat, check the idler pulleys for noise and also examine the radiator and see if it has any warpage or bulges - might as well do the whole lot in one sitting.

[john_p]

Definitely do water pump and make sure you bleed the system properly, check the belt as well to make sure it isn't perished. Definitely do not drive without cooling working as you risk permanent damage to the engine.

[carl24]

ive just finished doin the thermostat and its made no difference, also should there deosnt seem to be water in the pipes at the front of the engine so yeah the pump is next, which is the correct way to bleed the system once fitted???

[carl24]

does any1 know where i could get a new water pump from cheap?? and quick lol

[john_p]

www.gsfcarparts.com

failing that..main dealer?

[carl24]

ive just replaced the water pump but how do you bleed the system properly??

[Victor101]

Easy. There are various internet stories of jacking up the front of the car, standing on your head, doing a merry jig etc.

Don't just tip it in through the radiator cap, you'll just get a mahoooosive air lock.

Take the top rad hose off the radiator but leave the radiator cap ON.

SLOWLY pour anti freeze into the hose - this is filling the engine and the level will build up in the rad too. Keep adding it until it starts to spill from the radiator top hose elbow - that means the rad is full as well. Refit the hose and fire it up, heater on. Run it up the road, give it the beans until you feel the heater starting to pump warm air.
There are tow bleed screws. One is on the rad next to the cap, the other is on the plastic thermostat housing. Gove both a crack open to let any remaining air out. All fun and games.

[carl24]

HI EVERYONE IVE BLEED THE AIR OUT TO THE BEST I CAN LOL, THE CAR WAS DRIVIN FINE FOR 40 MINS THE THE TEMP GAUGE WENT UP TO THREE QUARTERS BUT NOT INTO THE RED WHAT COULD IT BE, IVE REPLACED THERMOSTAT, WATER PUMP