Padilla74

hi there, just wanna say thank you for any responses to my post.

i have had the car for 1 year with no issues at all. it currently has 90k miles and its a 2007 525i. I was driving on the hwy at 70 mph for about 5-10 min at 70mph when i got a yellow message overheating on the i drive, then rapidly a red one to pull over. i pulled over right away and i herd the fans go nuts. i waited 30min and started it up and had no warnings or malfunctions on my i drive. drove it off the hwy for about 5 min and again the yellow message popped up and i turned it off while i was parking at the gas station. i left it there for a couple of hours till the sun went down and drove it home with the heater on 7 miles. it drove normal as always till about 2 blocks away from home i got the yellow message and the fans went crazy. i let it sit for 10 mins then i drove into my driveway. this whole time driving back i had no check engine light on, malfunction or anything and the car drove as usual. its a little strange to me. i would appreciate any help before i take it to the stealership. Thanks

bcromwell

Likely the water pump is going/gone bad

Padilla74

that's what im thinking but i was told that if the pump or thermostat go bad the censor goes bad as well and activates the computer and the check engine light lights up.

pjinca

PM member Healthservices, he is a pretty damn good mechanic (used to be a shop foreman) and can diagnose and repair for a decent price

I am guessing water pump, the plastic impellers in our water pumps aren't really made to last forever

AUSaxon00

I had these exact same symptoms in my '06 525xi and it turned out to be the electric coolant pump. Have your fault codes read by someone with a BMW code reader. My error code was coolant pump speed deviation. The repair will cost you about $1,100 at a dealer, $550 for a remanned pump and the rest labor. Based on your mileage, you were living on borrowed time. These electric pumps are a known weak point in the cooling system.

Check out this thread for more info on the pump:

https://5series.net/forums/topic/108...1#entry1290847

AchtungE60

well i'm not going to read everyone's post but leaving the car sit for 10 mins - 1 hour isn't going to help. This car reaches operating temperature quickly and takes a LOOOONG time to cool down (probably about 6-7 hours easy) so hopefully you didnt do damage to your engine. Seriously. I am not trying to scare you but I've had friends do this to their BMW and drove 3-4 miles with the car completely cold and the outcome was a warped head.
As far as fan, it's been mid 80's - 90's outside and my fan runs hard too when the car has not yet reached operating temperature.

I have an 04 530 and I haven't had any problems with my waterpump yet. I'm at 129K on the clock. But you never know. I may have a different setup since I have an M54 engine

korrosive

Just curious, but how many heat bars was it showing on the RPM gauge when it was throwing the errors?

HKninja

I just replaced mine at 51k miles. $1200 new pump and thermostat and labors.

sanjsanj

They aren't heat bars mate.

At 0C coolant temperature, mine indicates 3.9k. Once up to 50C, it goes up to (the maximum it shows on a diesel engine, of) 4.5k. After this, from 50C to the normal operating temperature of 90C, the variable bars don't move at all. Although these bars are based on the heat of the engine, they can't be used to determine the heat of the engine. The only message they give you is "it's safe to rev to this rpm now", and nothing more.




Best thing to do it check the coolant temperature via the secret OBC, menu number 7.

korrosive

I hear what you're saying as far as the bars not being a reliable source of accurate information, but what I'm trying to figure out for anyone that's experienced the overheating is what those bars did. I've had my serpentine belt go out and subsequently noticed my heat gauge go to max, so I often peak at the heat whenever cruising on the highway and on long trips especially. I doubt I can quickly access the secret menu while cruising on the interstate...