Coolant Problem, Need Help

All

As some of you know from my posts I have had my CHECK COOLANT LEVEL warning come on and off sporadically for the past few months. I had the garage swap out the coolant sensor as I had heard numerous issues there but it still continued. No leaks, level looked good and wiring was okay. On Thursday I took the car in for some other things and at the same time had them check the coolant again. They topped off and had no issues until today where after about a 30 minute drive I suddenly see the coolant level dive into the read and get the coolant temperature warning before the car starts to overheat (luckily 1 block from home). Let the car cool down (fan was on for about 15 minutes after car was turned off) and noticed no leaks still.

Any ideas on this as it is driving me crazy. Could the sudden overheating be because he over filled the tank >?

Thanks

WC

Mine did the same thing. I finally discovered that the plastic holding tank had ruptured internally. It's actually a tank inside of a tank, which also houses coolant level senstor.

Do a search on this topic. Lots of info and it's easy to replace yourself. Runs about $80 I think. The hardest part is refilling the system with coolant. There's a "bleed off"procedure you have to follow to get all the air out of the system. Again, do a search...

Best of Luck

LEADFOOT

Did you recently work on the heating/cooling system recently? Did you re-bleed the coolant correctly?

Others possibilites can be the coolant temperature sensor, which locates behind pusher fan can go bad or leaks from water manifold (next to the firewall). Best, to have system pressure check before catastrophe overheat.

Cheers,
TP.

Originally Posted by Wildcat_1

All

As some of you know from my posts I have had my CHECK COOLANT LEVEL warning come on and off sporadically for the past few months. I had the garage swap out the coolant sensor as I had heard numerous issues there but it still continued. No leaks, level looked good and wiring was okay. On Thursday I took the car in for some other things and at the same time had them check the coolant again. They topped off and had no issues until today where after about a 30 minute drive I suddenly see the coolant level dive into the read and get the coolant temperature warning before the car starts to overheat (luckily 1 block from home). Let the car cool down (fan was on for about 15 minutes after car was turned off) and noticed no leaks still.

Any ideas on this as it is driving me crazy. Could the sudden overheating be because he over filled the tank >?

Thanks

WC

It's interesting, let it cool off over night and checked this morning and the coolant tank is almost bone dry. Still no signs of a leak underneath. THinking about just having the coolant tank replaced

Erirdest thing was although this has been an ongoing thing it only overheated on Saturday after the guy did the top off on Thursday. Nothing this bad before

if i were you when your confidence level goes down to doing garage work, bring it t an indy shop. but if you ask me, spend that $550 on parts and do your own labor to replace th whole cooling system. i have a feeling you have an internal leak and the coolant is evaporating before it hits the ground. ask CN90, he's an expert on cooling issues.

Put coolant in today and came straight out. Looks like leaking half way down the radiator on the drivers side like a seal or something has gone, ideas >?

Originally Posted by Wildcat_1

Put coolant in today and came straight out. Looks like leaking half way down the radiator on the drivers side like a seal or something has gone, ideas >?

Pretty common actually, Either the plastic has cracked or the tank seal has let loose.
We have the radiators on our website if you need one. Depending on your mileage you may want to consider doing the expansion tank, waterpump and thermostat since you will be working on the cooling system any how.

picked up my car today after traveling for business this past week. my "check coolant level" light was coming on just like yours. at first the tech called back and said they topped off the coolant level due to it being low. they said they didn't see any other issues. i told them i had done the same a few days prior and even filled a little more than what was noted in the book. well, after a pressure test, and the tech thinking all was good, the radiator ruptured. so, upon picking up, the shop blessed me with a new radiator.
keep an eye on your system, but i'm thinking your following the same exact pattern as i had happening. when i dropped it off last saturday before getting out of town, the light was coming on more frequently whereas it was more sporadic earlier. if i hadn't "challenged" the tech with providing more information and asking him to go back and run diagnostics "again", i could've easily picked it up and blown the radiator on the way home.

http://bimmerboard.com/forums/posts/361164

Read through that thread and the links carefully. DIY is there.