[Guest]

Hiya chaps, while crawling in traffic the other day (for nearly an hour) my tempreture gauge started heading for the red. I switched the car off before it hit the red mark so it didnt implode/explode on me. I did 250 miles after that and it was absolutely fine and never went above the half way mark.
The fan is definately working properly and it cant be stopped with a paper or anything. Also no water and coolant have mixed and it runs fine so Im doubting its the head. (that was completely rebuilt 7k ago)

I checked the coolant and it had lost around quarter of a pint so I topped it up when the engine was cold. I checked it the next day again after a short run and the coolant level had dropped again. I squeezed the top hose once and the coolant level went back up to the exact correct level.

The next morning I went to the airport at 4am and with the climate unit set to 22 degrees it blew cold. I incresed it up to 32 to get a bit of warmth in the car and it blows hot. Ive discovered at 31 degrees it will only blow cold and at 32 degrees it blows hot.
The coolant level appears fine when cold and my local garage say they cant find any airlocks in the cooling system.

Can anyone shed any light on this?

 

[Guest]

Im guessing your as stumpes as me then lol

 

[xXxStKxXx]

Try the bleed process again-you have to raise the front as high as you can possibly go-the 5 series is notorious for getting an airlock and has to be raised because the matrix and radiator are on the same level so very hard to get the airlock out :frown
If this doesn't solve it then come back here again and we will have another think on it.:thumbsup

 

[xXNealXx]

Exactly what StK said....and here is the proper procedure to bleed the system.

1.Jack the front of the vehicle up onto stands as high as possible,
2.Turn the ignition on,engine off,heater on fan setting 1 and temperature fully hot,
3.Remove the rad cap/expansion cap,remove the bleed screw from the radiator and IF you have them the bleed screw(s) from the thermostat housing/top hose, return pipe or EGR thermostat.
4.Fill the radiator up and keep pouring till there are no more air bubbles coming out from the bleeds, using a funnel that fits tight in the radiator neck and filling it full of water will help push any troublesome air out, when good you can then install the bleeds and tighten down(don't snap them),ensure the rubber O-rings/seals are still on the screws/on the bleed holes.
5.Suck some water out so it's not full to the brim, replace the cap and then start the car. Run her up and check for heat from the vents when warm and check if over heating still persists. You may have to bleed troublesome cars twice(but rare).
6.If all is good then check the water level again in the morning when cool.