E36 low radiator water

[awyeah]

The radiator of my E36 is consuming a lot of water. Based on the age of the engine, I believe it is normal to consume more water, but this is quite much. I check and refill it almost weekly. Normally after a week the radiator is half or less than half. I need to check every week. I drive 400-500km weekly.There is no leak from the radiator and I don't see much rust in the water, meaning the radiator is in good condition from inside. The engine and air-con fans seem to be running fine. I put a non-boil coolant inside the radiator, still the radiator was half empty after a few days.Will it be better to use the original bmw coolant which is around RM20-RM30/bottle to solve this? Any suggestions? Also I think I might need to get the radiator expansion tank which is compulsory.

 

[Hellraiser]

lemme guess, you haven't gotten the mechanic to hoist the car and check the hoses and flanges or do a pressure test, so how can you say it is normal to consume water?

better get it checked and parts replaced if needed or you might end up overhauling your engine and a bigger hole in yer pockets

cheers!

 

[awyeah]

lemme guess, you haven't gotten the mechanic to hoist the car and check the hoses and flanges or do a pressure test, so how can you say it is normal to consume water?

better get it checked and parts replaced if needed or you might end up overhauling your engine and a bigger hole in yer pockets

cheers!

Thanks for the info bro. Yes, I will mention this problem to my mechanic. I do believe high temperature can cause various threats to the engine and other parts. So have to get this problem rectified soon as possible.

 

[z///]

Check it & do a pressure test like what he said. - Sometimes there's air in the cooling system which might explain the lose of coolant.- A pressure test might solve this.

I afraid the coolant might go to the head gasket & damage it. No visible leaks on the floor? It's normal to lose out coolant few inch but every week is a lot.

Area to be check- Water pump, Thermostat, radiator, Bleed screw, Hoses- make sure they are tighten.

Bleed screw is this one:

 

[Hellraiser]

if your car has overheated before, parts will get affected and you will have fire fighting issues eliminating every single suspect

 

[infinityKL]

old e36 oso, should not consume any water... pls get it checked, might lead to cracked cylinder head

 

[awyeah]

Thanks everyone for the info.

I think to have mis-leaded some information, I was not aware with the radiator tank capacity. After doing a search online, I found that the E36 radiator tank can normally fill in 2+ gallons, which is around about 7+ litres.

Previouly, I only saw the volume of the alternator cooling duct (attached picture by z///). What I mean't is weekly, I normally fill, 1litre of water (1 disposable plastic water bottle) and the radiator fills up to the max.

How to inspect the "bleed screw" check it when the engine is hot and running?

I filled another bottle of 1litre today so the water is at maximum, there was some left in the bottle. After that i started the car, noticed some leaks from the bottom, leaked for a while, after that it was okay. Drove the to office, after that inspected below, there was no leakage.

I believe the initial leakage after filling the water to the max is the problem.

Also regarding the cooling system, for the e36 aircon fan, should the aircon fan start immediately or sometime after you start the aircon? or it is used only when necessary? its speed varies based on the temperature of the engine?

Is 55-60% temp acceptable on an E36 hot day with the aircon running? Normally my temp indicator is 50%.

 

[king82]

you shouldn't fill the radiator till the max...leave around 4-5 inches of unfilled area...

your mechanic should be able to find the cause after some checks...

 

[evilnickwong]

It might be leaking very slowly, I don't think you should ever need to top up water in a sealed coolant system.

 

[awyeah]

you shouldn't fill the radiator till the max...leave around 4-5 inches of unfilled area...

your mechanic should be able to find the cause after some checks...

Yes I leave a few inches of space, don't fill it till the cap.
I will send it to the mechanic for a pressure test, should be okay.

 

[awyeah]

It might be leaking very slowly, I don't think you should ever need to top up water in a sealed coolant system.

I also believe, a closed water system should not loose any water (unless evaporate which is not possible), so yes leakage is there, confirmed, but substainally less. Have to send it to the mechanic to diagnose.