Cooling system HELP BMW E 36 m52b25

[Hazem83]

Hello bimmers need your assistance to diagnose my problem, i have changed my radiator with a new one and it worked well for 2 weeks yesterday was driving the car all day without any problems when i was driving home after many drives the car heated up so i left the car till cooled down when i removed the radiator cap and the car was cold some water spilled out of the radiator once i removed the cap with car off and cold, after that i bleed the air and filled it again and teated the car for half an hour and did not heat. Any explanations pls

[bmwdirtracer]

It sounds like you probably have compression in the cooling system from a blown head gasket / cracked head.

Why did you replace the radiator? Has the engine ever overheated....gotten into the red zone of the gauge?

A single trip into the red can kill a BMW cylinder head.

How, exactly, did you bleed the cooling system of air? When's the last time the water pump, thermostat, fan clutch, and other cooling system components were replaced? The entire cooling system should be replaced every 8 years or so.

[Hazem83]

Its never been reached the red zone, and i did change the radiator because the old one was leaking. Note that there is no white smoke or oil in water or vice versa

[bmwdirtracer]

If the cooling system was filled to the correct level, and the car was allowed to completely cool down, and after this, the expansion tank cap was opened, and coolant came out that cap, SOMETHING pushed it out, because it should have been halfway up the bottle, not coming out the top.

[Hazem83]

Thanks bro

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Any other opinions, if it happened with anybody please share your experience

[Hazem83]

Up

[dworthy]

What year?

Do you have access to diagnostic equipment?

[Hazem83]

1992, i requested DIS inpa cable and it will arrive this week but now no

[dworthy]

Okay, with the OBD-1 you have a bit limited on what you can see from INPA. What you need to know is if the waterpump is working, if the thermostat is opening properly. Once the car is at normal temp, I would use a temp gun to read the hose going to the radiator and back to the motor. The upper hose should reach temps of 95-105C and the lower should be around 55-65C, this will also check to see if the radiator is doing its job.

[MarcoZandrini]

Here’s a free and easy test for a bad head gasket:
- make sure the cooling system is properly bled
- make sure the cooling system isn’t over-filled
- get the engine up to full operating temperature
- allow the engine to fully cool (overnight is best)
- squeeze the upper hose
- hard to squeeze indicates a bad head gasket
- easy to squeeze indicates the head gasket is ok

[bmwdirtracer]

OR, if the coolant comes out of the cap when it's opened, stone cold. That was my original point. Coolant doesn't grow, except with temperature. If there's more coolant apparent , at the same stone-cold temperature, the culprit has to be combustion chamber gas.

[Breeze1]

I think there might be a misunderstanding as per what you call "cooled down". After it overheated and you waited until it had "cooled down", it was not stone cold, just cold enough to allow you to open the cap without getting burnt.

So there was still warm/pressurized air in the system, hence the water spilling... you say that after bleeding it and driving 30min there was no issue.

I take it that the system was not properly bled when you replaced the radiator and pressure had been slowly building up, until it actually overheated.

If I were you I would bleed the system again in the morning, when starting the car for the first time, and see how it goes from there.