Radiator changed

[buzuzih]

Had changed the radiator on my 520I -e39.
Any one can tell me the procedure to remove the air with the water or what I have to do now once I fill it up with water.
Thanks
Regard
Buzuzih

[marti5]

Ok, Best performed from cold;

1. turn key to pos II ( do not start car )

2. put heat control to Max 32 with fan set at lowest level

3. begin to fill with 50/50 coolant/water mix

4. keep filling very slowley until float is level with the top of the expansion tank

5. when float has settled level with the top, replace cap, start engine

6. open screw next to exp tank to let out air (bubbles) !! keep an eye on temp gauge

7. when car is stone cold, check float and top up as required.

My float took 2 weeks to stay level with the top of the expansion tank, I checked and topped it up about every 2 - 3 days, and it has now stayed level for 18 months.

******* level check only when stone cold ********

If you get low coolant level warning then you will have to add some regardless of wether the engine is warm or cold, but not to much!! 1/2 cup say a time. If the float pops right out when engine is hot/warm dont panic this is normal.

If you do happen to overfill this system it will chuck it out.

[buzuzih]

Thank you very much Marti5, prompt and very informative as always.
Had done what you said and up to now it's functioning fine.
Best regards
Buzuzih
Malta

[rashid]

Had different problem of low coolant level almost every one month or 3000 KM. The minus is around 1 L / months or 3000 KM.

Any idea of the cause?

My car is 530i, 2002 ...

[marti5]

You either have a small leak or a head gasket leak, if you've have covered more than 80,000 miles I would be looking around the waterpump area, you cant really miss a coolant leak as when it dries it leaves a whitish/greeny, powder/residue.

[rashid]

I think you have an excellent experience & really appreciate your help.

Let me first focus of the head gasket leak, is it risky for the engine & how I can confirm it?

Note: normally I am using normal tap water but not green coolant one.

[rashid]

Found the leak, in the radiator plastic frame ... closed to where it connects the pipe that is going to the engine. Can the radiator be repaired or should change it???

[marti5]

Change the radiator,dont try and fix it, it won't work, also NEVER just put tap water in the coolant syatem this will corrode the head, drain out whats in there which you will anyway when you change the rad and do a 50/50 water and coolant consentrate mix or buy ready mixed but this is costly and you will need to buy two 5ltr bottles .DO NOT JUST USE TAP WATER!!!!!

[rashid]

Mechanic told that was not really a leak & suggested me to apply pressure to identify the leak. He also told me one cup or two in one month is normal in BMW.

I have alraedy purchased the coolant mix ....

[marti5]

One cup or two a month ok!!!!! in a BMW, Can you ask your mechanic where the auto coolant refill is please, as mine has not lost a drop in 18 months????? so mine must top itself up then, change the radiator, if you dont one day it will just go and you will cook the engine, as for your mechanic I would'nt be going back to him, sounds like a total novice.

[rashid]

Noted with many thanks ...

[buzuzih]

Hi I'm back,
The red light of the water heath temperature came on again after two weeks.
I had changed the radiator, the thermostat and checked for any leakages.
The water is not getting short, but is boiling. It worked perfectly for two weeks, but now it started with the same problem except that water is not being lost.
I had noticed that the top and the left hand pipes are remaining empty without water.
I had checked to have the bubbles removed, done after filled it again, but it done it again.
What could it be the problem. Any idea please.
Thank you forwardly.
Rgds
Buzuzih

[marti5]

If you have pipes with no water in the thermostat is not operating properly (not opening) or you have a blockage, which I dont think you have either as its been fine for 2 weeks, what does the temp gauge say when the car has fully heated up?.
If its passed the middle the water is getting to hot, this could be caused by the fan not operatating properly, which would be the viscous coupling failing, which is common on many makes of car.

[buzuzih]

Hi Matrt5.
Many thanks for your prompt reply.
The fan looks that is working fine.
The temp gauge goes up and the red light come on.
While ideal, the temp goes only to yhr mid of the gauge, but once I drive it for about 4min, the temp gauge goes high and the red light comes on.
Buzuzih

[marti5]

thermostat is not opening