E46 Coolant Light

[Paul Naidoo]

Hi Guys

I have a 2004 E46 318i F/l N46 version. There are a few niggly issues.
The coolant light keeps coming on. I have replaced the following:
Radiator, Hoses, Thermostat, Waterpump, and yesterday, the Expansion tank.
The light does not come on when car is idling from cold. It only comes on when I drive.
I waited for car to cool down to check if Water is short, however when I tried opening the cap, the water wanted to come out of the bottle. There was a Gurgling sound, much like there when dring the last drop of milkshake through a straw.
Any suggestions to fix this?
Paul

 

[ChrisBrand]

The gargling sound could be air trapped in the system. Did you bleed the system properly? This could be the reason for the light given that theres nothing wrong with your oil level sensor

 

[Paul Naidoo]

No, I didn't bleed the system. Any DIY instructions on how to do that?

 

[Yuben]

Never try and open the cap when hot.
When cold idle it with the cap open, check the water level and release the plastic star screw to let the air out.

Or at least I think thats how u do it.

 

[Crash_Nemesis]

My brother had the exact same problem. He has a e46 318ti.

This issue was there for a few years and he just started ignoring it. One night his car overheated and he blew the headgasket.

Long story short, had to replace headgasket, all water hoses, thermostat etc. Car runs fine now and that light no longer comes on.

Don't ignore it.

 

[RowenS]

My brother had the exact same problem. He has a e46 318ti.

This issue was there for a few years and he just started ignoring it. One night his car overheated and he blew the headgasket.

Long story short, had to replace headgasket, all water hoses, thermostat etc. Car runs fine now and that light no longer comes on.

Don't ignore it.

what was the fix to the orginal issue?

 

[lucian]

When you bleed it, make sure the valve where you release the air is the highest point. You can even jack the car up a bit. Air always goes to the highest point in the system.

Might wanna check also that the fan comes on when car is hot. Some f@cker who worked on my aircon once, removed the fuse and I drove like that for almost a year until one hot day in heavy traffic the engine almost overheated. Took car to BMW and they just chucked fuse (think it is the big one 50amp, not sure) back in it's place and voila, fan spinned again. Cost me R300 though.

 

[Dewald Basson]

Nice video on how to do a flush and how to bleed.

[video=youtube]

 

[Chucky]

Bleed the system properly, air in the coolant system will cause the light to come on and go off while driving or when engine is at operating temp.

With all the work you done you should have bled the cooling system afterwards.

 

[Paul Naidoo]

OK. I did all the above, however, I noticed that the water is still dissapearing somewhere.
There is No signs of white residue on oil cap, etc. No signs of seapage anywhere in the cooling system. I replaced the Expansion bottle as well. No signs of overheating on gauge.
Where is the coolant going to?????

 

[ChrisBrand]

How often do you need to top up?

 

[Yuben]

Check thermostat housing, water pump and hoses.

Only when u remove the bottom covers can u see the build up

 

[Paul Naidoo]

Hi Guys.

I finally managed to sort the problem. It was the Housing unit for the Expansion bottle that was damaged.
Wow so glad that it didnt cost an arm and a leg...
Thanks for all the asistance.

I still need to replace the Heater Control Valve though. Any pricing available?

 

[GPGrobler]

Paul,

Glad you got sorted, E46's are still quite good bang for a buck, it depends on where you shop though. Try Goldwagen for the Heater Control Valve. :thumbs:

 

[Zabo]

Hi Guys,

I'm having a similar issue with my 2004 E46 325i, water vanishing somewhere once pressure builds up. Suspecting expansion tank. Gonna DIY the removal soon. Any tips/tricks to removal I should be aware of? Or even possible areas on expansion tank I could check for leakage/failure?

Thanks in advance!