E46 cooling / water

nicwes

///Member
Hi guys

So my car is freaking me out at the moment. This morning on my way to work the coolant light comes on. It seems at random. I drive to work on Attebury, so it is not fast driving. If the car revs to 3000rpm it's a lot. Weird thing is, when I stop or drive at crawling speed, the light goes off. When I do around 70kph the light comes on again. As soon as I am stationary for a bit, it goes off.

Filled her up before driving home. Took about 1lt of water. About 10min after I left, light comes on again.. And the same story as this morning. Idling or very slow driving it goes off. As soon as I pick up speed, the light is on again.

Can someone please try and explain what thus might be. Mileage is 137800km
 

Yuben

Senior Moderator
Staff member
There should be traces of water on the covers since u filling 1L water, the water has to be going somewhere.
There is definitely a leak, beware, the E46 cooling system is very weak, best u track and trace the problem or u could be facing a costly repair:coolShake:
 

S1NGH 911

BMWFanatics Advertiser
Official Advertiser
Get this checked quick, last thing you want is for it to overheat :thumbdo:
 

Nikhil

Honorary ///Member
Hmmm monitor the fluid level and heat gauge. If the level drops then definitely a leak if it doesn't then you have a faulty level sensor :coolShake:
 

S1NGH 911

BMWFanatics Advertiser
Official Advertiser
Nikhil said:
Hmmm monitor the fluid level and heat gauge. If the level drops then definitely a leak if it doesn't then you have a faulty level sensor :coolShake:

Surely if it took 1L to top up, then it's not kosher :tiptoe:
 

Lizzard

Active member
Did you top up the water in the radiator when it was empty prior to all of this?

When did this start and what did you do prior to it, like added water to the radiator due to it being slightly low etc?
 

nicwes

///Member
There was a small leak back in November, but haven't touched the radiator/water cooling since. Only today when it started with the warning light


Mind made up. Not going to wait for the weekend. Going to have it checked out tomorrow!
 

Yuben

Senior Moderator
Staff member
With that amount of water needed to be topped, it can only mean a serious leak somewhere.

Like in my case it was the radiator as well as the top radiator house that had to be replaced today.
 

Nikhil

Honorary ///Member
S1NGH 911 said:
Nikhil said:
Hmmm monitor the fluid level and heat gauge. If the level drops then definitely a leak if it doesn't then you have a faulty level sensor :coolShake:

Surely if it took 1L to top up, then it's not kosher :tiptoe:

Yep but we dont know when last he topped up / checked water levels prior to that
 

nicwes

///Member
I haven't topped it up since driving home. I want it to be completely cold before opening the radiator
 

Lizzard

Active member
Ok, I had the same problem (water display logo came on the dash displaying water low) where I had topped up the water in the radiator and then went for a drive, about 5 blocks later the car overheats, took 4 hrs getting it home, 330i doesn't love being thirsty.

You did the top up and might have done it incorrect ! Sounds stupid but believe me you can even mess this up :biglol::roflol:

Ok, when you car is cold, park it with the nose uphill (not necessary to look into the sky but uphill will help). Open the bleed valve on your radiator water tank and the one at your waterpump (cant remember exactly where it is but its there) then you open the radiator cap. Dump the hose pipe (yes that's correct hose pipe) into the radiator and open the tap with a slow stream like watering the plants example. Now go into the car and switch the ignition on to all light on dash is on but DONT START. Then dial your temperature control inside car to max heat and the fan speed to min.

Go make coffee and return 5 minutes later then look at the bleed valves, both the waterpump and radiator ones, if there is still bubbles continue tapping water if not then your ok and close the bleed screws first then close the tap and remove the excess water from the radiator water tank. Switch off the ignition.

Go and do the bmw style driving and return home, car should be ok.

The thing I never read was that when the car is low on water and just adding water doesn't work on bmws:biglol:. you need to bleed the sucker, :hammerhead: bmw engineering.

Just do that and your problem will 99% be gone, I had the same issue. The reason why your car will be ok and then overheat and then be ok is because it has air in the system and that needs to be bleed out.
 

Bazza

Active member
Lizzard said:
Ok, I had the same problem (water display logo came on the dash displaying water low) where I had topped up the water in the radiator and then went for a drive, about 5 blocks later the car overheats, took 4 hrs getting it home, 330i doesn't love being thirsty.

You did the top up and might have done it incorrect ! Sounds stupid but believe me you can even mess this up :biglol::roflol:

Ok, when you car is cold, park it with the nose uphill (not necessary to look into the sky but uphill will help). Open the bleed valve on your radiator water tank and the one at your waterpump (cant remember exactly where it is but its there) then you open the radiator cap. Dump the hose pipe (yes that's correct hose pipe) into the radiator and open the tap with a slow stream like watering the plants example. Now go into the car and switch the ignition on to all light on dash is on but DONT START. Then dial your temperature control inside car to max heat and the fan speed to min.

Go make coffee and return 5 minutes later then look at the bleed valves, both the waterpump and radiator ones, if there is still bubbles continue tapping water if not then your ok and close the bleed screws first then close the tap and remove the excess water from the radiator water tank. Switch off the ignition.

Go and do the bmw style driving and return home, car should be ok.

The thing I never read was that when the car is low on water and just adding water doesn't work on bmws:biglol:. you need to bleed the sucker, :hammerhead: bmw engineering.

Just do that and your problem will 99% be gone, I had the same issue. The reason why your car will be ok and then overheat and then be ok is because it has air in the system and that needs to be bleed out.

I'm going to do this tonight. My 330 also needs a top up every now and then so probably just needs to be bled properly, one question though, what about antifreeze?
 

beezo003

New member
If you have antifreeze in your car, its easier to spot a leak as it will form crystals...check your pipes from waterpump all the way to radiator
 

Lizzard

Active member
I never put antifreeze into my E46 330i but then I didn't feel the need to.

BMW advice us of 50 / 50 antifreeze and water ratio. Buy a 3Lt from Goldwagen for like R150 and then add 3 liter water but only do that if radiator is completely empty

Answer: don't warry for now about it, do that on your next service.

Both my 330i, E46 and E90 (gave my E46 to my younger brother) use water, top up every now and then but like maybe 500mls, maybe

I think it is how you drive them that accounts for that, I do like some spirit driving from time to time or if an idiot :hammerhead: with his GTI tries his luck :rollsmile: :roflol:
 

beezo003

New member
antifreeze helps with protecting your cooling system so that it doesnt perish as fast as it would, its not only for the cold but also for the heat
 

Chucky

Active member
beezo003 said:
antifreeze helps with protecting your cooling system so that it doesnt perish as fast as it would, its not only for the cold but also for the heat

Indeed
 
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