Overheating experience on my M50B20

[rainman55]

Hi fellow sifu's,I have a question on my M50B20 radiator that I hope to seek the truth :rock: I had an low coolant level this morning and started to add distilled water into the radiator, with the radiator cap and bleed screw opened. However, the coolant level never reach the "COLD" mark. After adding about 2 litres of distilled water and though I did not see the level reach "COLD", I decided it's enough and went ahead to close up and drive off. Temperature started rising and I stopped to check. Well, coolant level was not "COLD" but it's just 1 mark below "COLD".So I added more distilled water, again, with the radiator cap and bleed screw opened. The coolant level still doesn't reach the "COLD" mark. After adding another 1/2 litre, I closed up and drive off. Temperature rose after a while. I stopped to add distilled water again.This time, I only removed the radiator cap. The coolant level rose just above "COLD". I closed up and drove off. 20km later, the temperature is still in the middle of the gauge.What did I do right/wrong?Thank you.

 

[skinhead]

the temperature is still in the middle of the gauge.

What did I do right/wrong?

Thank you.

temp needle will b at d midle on normal operating temp

 

[rainman55]

temp needle will b at d midle on normal operating temp[/QUOT

Thanks Skinhead,

I know the needle should be in the middle. But did I do anything wrong that caused the few overheating in the 1st place? And also why is the coolant level always way below "COLD" no matter how many litres of water I poured into the radiator?

Cheers
RM55

 

[seech]

rainman, try this. Open the bleed screw and radiator cap. Fill water until water starts to come out of the bleed screw. Keep filling until only water with less bubbles comes out of the bleed screw. Close bleed screw and radiator cap. Start engine and open bleed screw. Allow water to flow out. Squeeze top radiator hose to ensure all air bubbles are removed from the cooling system. Allow water to flow out until radiator level drops to around the 'cold' level and close off the bleed screw. The next time engine is cold just open the radiator cap and fill to 'cold' level. DO NOT open the bleed screw again. Bleed screw should only be used to bleed air out of the system when the engine is running.

 

[chaiks]

rainman, I think your mistake is the first time when you top up your water, you should not open the bleed screw. As seech said, its only needed when you want to bleed air out of the radiator, that is only after you service your cooling system or you experiencing overheating because of trapped air inside.

To top up coolant in radiator, just need to open the radiator cap.

 

[din mirage]

coolant

u must on the heater after u top the water afew minute. no need to open the bleeder nut when the engine is running. first u open the bleedr nut and radiator cap. top up water until the buble aot from bleeder nut gone. then close the bleeder nut. switch on the heater and make sure u heater motor at fire wall working. aftr a few min, off the heater and just top up water if low. im now wrking at bmw. dont worry top up the water fully and ignore the sign of coolant level.

 

[wc9922]

These BMW M50/52 engines need religious care of the cooling system. The heads are very sensative to temperature spikes. I learned my lesson cause it just happen to my car! Although not overheated but the rad cap failed and was letting out water. It was lucky it happened in a petrol pump and not in abloody jam.

The whole cooling system change cost me quite a bit of money but I didn't know how well the previous owner took care of the care so I just changed a whole lot. should last another 4 years or 100,000 kms.

Yes the advice of the bleed screw and heater switch is true. Make sure all air is relieved or you will have hot spots in the engine due to the air pockets which allows the water to change to superheated steam in the voids. This will cause some temp spike readings. This occasional spikes are not good for the cooling system and not to mention the water pump cavitation as the steam bubbles collapses.

 

[onezeone]

The heads problem is true. for the pass 3 month i have already change 3 times it happen to my honda civic EK. when i change the head the temprature came ok again. it happen bec the water in redeator came out thru add water tank. some time i feel afried to open the head, becouse it so sensitive.

 

[macgy]

bro, do u still need to top up water frequently?. if yes, pls change the radiator, my radiator is losing fluid every week until i decided to change a new radiator. open up d old radiator n found out d seal at the plastic tank is leaking, amazing as this is only 2 yrs old!

 

[longan]

erkk just happend to me... 1st: radiator leaking at plastic seal> change 2nd radiator> long distance.. overheat > (towed to workshop) after refilled collant... test by mech ok.. now still at workshop. dunno the outcome yet.. erkk.. worried head problem!!! haiyoooo