Now what ?

my car has been overheating for some time now, every other week i have to sit on the sidewalk, cool it off and go at it again
things i've changed, well, everything you see in this pic + cleaned the radiator...



car's still overheating
help

Try bleeding it. Look for a link in the wiki with instructions.

What about your expansion tank? Did you replace it as well? Are you losing coolant or just running hot.

the entire cooling system has been pulled apart and checked, no leaking anywhere.
it's simply running hot...

Burped properly?

How are your spark plugs?

Is the main belt routed correctly? I'm pretty sure if it wasn't it would be loose, but make sure it's routed properly so the water pump is spinning in the correct direction.

Of course, also make sure you've bled all the air out. It may require a couple tries.

Originally Posted by av98

Burped properly?

How are your spark plugs?

spark plugs are new, what do u mean by "Burped properly"?

Originally Posted by jvr826

Is the main belt routed correctly? I'm pretty sure if it wasn't it would be loose, but make sure it's routed properly so the water pump is spinning in the correct direction.

Of course, also make sure you've bled all the air out. It may require a couple tries.

i'll check the belt, and yea basically it's been bled from everything since everything related to the cooling system has been taken apart and checked

Originally Posted by heztheone

spark plugs are new, what do u mean by "Burped properly"?

i'll check the belt, and yea basically it's been bled from everything since everything related to the cooling system has been taken apart and checked

Did you raise the front of the car when bleeding the system? That's important to get the trapped air out. No other way of doing it.

here's what happened, when i took it to the radiator guy, the car was sitting on a 20% road inclination, so the front of the car was raised.
he took the radiator, water expansion tank, the hoses and everything off (everything in the pic in post #1) was apart.
he cleaned the radiator, changed the hose attached to the tank and the plastic thingy attached to the radiator near the tank since both were leaking, reinstalled everything and made sure that nothing was leaking, and off i went. so not sure exactly what's left to be done

Originally Posted by heztheone

here's what happened, when i took it to the radiator guy, the car was sitting on a 20% road inclination, so the front of the car was raised.
he took the radiator, water expansion tank, the hoses and everything off (everything in the pic in post #1) was apart.
he cleaned the radiator, changed the hose attached to the tank and the plastic thingy attached to the radiator near the tank since both were leaking, reinstalled everything and made sure that nothing was leaking, and off i went. so not sure exactly what's left to be done

What type of coolant was used?
does it overheat when your moving or stationary?
And did you actually see the guy do the system bleed


Sent from my VM670 using Bimmer App

Do this :

raise the front of the car (lift with floor jack and put on jackstands or park on a steepish hill)

turn ignition key to position 2. do not start engine.

turn heater on to full blast / hottest setting

open bleed screw on upper radiator hose

remove expansion tank coolant cap

slowly add 50/50 mix of coolant and distilled water until no more air and only coolant mixture comes out of bleeder screw.

close bleeder screw. top off tank if necessary. close cap

drive with an eye on the temp guage, you should be good. after car cools off, check coolant level one more time and top off if necessary.

call it good and reward yourself with the refreshing beverage of your choice.

That's the appropriate bleeding procedure. If you didn't see your mechanic do this, chances are you still have an air bubble somewhere in the system that's causing it to overheat. The entire procedure takes less than five minutes and the only tool required is a screwdriver to open the bleed screw.

The whole "raise the front of the car" to bleed the system is being grossly overstated in this thread. I RARELY ever raise any car post cooling system repair and just bleed it like normal and never ever have issues.

OP, sounds like your mechanic didn't bleed the system. Pretty easy to do. Just turn heater on full blast, open expansion tank and loosen bleeder screw next to the cap. Pour in distilled water very slowly till it starts dripping out the bleed screw area. Tighten screw, reinstall cap, done.

Originally Posted by heztheone

it's been bled from everything since everything related to the cooling system has been taken apart and checked

Just to make this clear: taking everything apart is what introduces air into the cooling system loop.

It's AFTER the whole thing has been reassembled that the system has to be bled of air ("burped"). I frequently see people post that it took them several tries to finally bleed out all the air. Give it a shot...

thanks guys for ur posts, i'll give it a try and let u know what happens

Originally Posted by smolck

The whole "raise the front of the car" to bleed the system is being grossly overstated in this thread. I RARELY ever raise any car post cooling system repair and just bleed it like normal and never ever have issues.

OP, sounds like your mechanic didn't bleed the system. Pretty easy to do. Just turn heater on full blast, open expansion tank and loosen bleeder screw next to the cap. Pour in distilled water very slowly till it starts dripping out the bleed screw area. Tighten screw, reinstall cap, done.

on my way home yesterday, started to overheat as soon as i arrived home, dodged a bullet there. before i started the bleeding process, i opened the expansion tank to check the water level and it wasn't missing a single drop of water.
anyways i started the bleeding, and it was pouring water from the screw area since the beginning, no air bubbles
2 things, i noticed that when my car overheated, the radiator fan was not on. it usually turns on, but i was a bit confused as why it was off when it overheated. and i read in another thread that the fan should also turn on during the bleeding process, again it was off.

i might have misinformed u guys
as i read through this thread and googled alot, i realized that i changed everything but the water pump. that could possibly be it. since everything else was changed, no leaking, and cooling system has been bled.
appreciate ur advice regarding my last 2 posts as to pinpoint the anomaly once and for all, cuz i'm starting to get aggravated

Go ahead and change the water pump if you think that is it, and since your fan wasn't spinning, check and make sure the fan clutch isn't worn out.

so no more leaking, no more losing water, but this is what's happening now.
the fan is not turning on when it should, i feel it spinning at times, but at others it doesn't. sometimes my car overheats since the fan is not on, if i turn the AC on, the fan starts and the temp cools down to normal.
any idea what's the problem that's causing the fan not to run whenever it should?

Just some thoughts...... sounds like your fan or related wiring/relays are failing maybe? or what about just the temp sending unit for the fan. I think it sticks up vertical into the lower rad hose. If the A/C runs the fan all the time, it would logically not care what the temp sending unit says. Maybe that's it. I think they're cheap like $20.

http://www.bimmerfest.com/wiki/index...or_replacement

I don't think that's the issue, i have no leaking whatsoever... I've been researching and i guess it's the engine fan, but how can i b sure that that's the part to replace? And if so can i find it sold seperately?

Originally Posted by heztheone

I don't think that's the issue, i have no leaking whatsoever... I've been researching and i guess it's the engine fan, but how can i b sure that that's the part to replace? And if so can i find it sold seperately?

The temp sensor may have a good seal but still be dead/failed or damaged wires/connector. I'm not sure how to test it specifically or the fan itself, other than to see if any error codes pop up on scan tool that would suggest the fan itself.

Bentley manual says fan should run a slow spin briefly after startup as a diagnostic and that when the A/C is run it doesn't necessarily start right away. (when the car is cold for safety) you should be able to spin the fan freely by hand.

Inputs to computer start fan:

rad outlet temp (sensor)
calculated coolant temp
vehicle speed
batt voltage
a/c pressure

both parts are sold individually. plug n play for both. fan slips into slots/shroud on back of radiator - have to remove intake ducting above fan area.

so had a chat with my mechanic, and he told me that i need to get the engine fan (?) that is in rectangular form sitting on the fan that tells the fan when to start.
as stated earlier, my problem is that the fan does not run every time it should hence why my car is overheating occasionally.
this part will solve my issue right ? i'm tired of changing stuff just to eliminate possibilities, and i want it to work once and for all
my question is, what is the name of this part to look for it? since i was unable to find individually, wherever i look i have to buy the entire assembly, which i don't need

The temp sensor is pretty easy to find - I found the one below on BMA. Most parts houses will have them.

http://www.bmaparts.com/ShopByVehicl...sensor@@Engine Coolant Temperature Sensor&mode=PA

Be sure to check the fan clutch, too.

Originally Posted by heztheone

so had a chat with my mechanic, and he told me that i need to get the engine fan (?) that is in rectangular form sitting on the fan that tells the fan when to start.
as stated earlier, my problem is that the fan does not run every time it should hence why my car is overheating occasionally.
this part will solve my issue right ? i'm tired of changing stuff just to eliminate possibilities, and i want it to work once and for all
my question is, what is the name of this part to look for it? since i was unable to find individually, wherever i look i have to buy the entire assembly, which i don't need

If you mean the relay/control module (silver/gray) box on fan unit, my understanding is they are not sold separately from the whole fan itself.