[Expired]

kk, went to a friends house, then we left to go downtown. Car starts to overheat after about 7 miles.. (right by my house)
So, we make a quick turn around and the car starts to cool back down and rest at 12 o'clock. Get about a mile from the house and it starts to heat up again, then right as I get to my house it gets right by the red. Stays near the red for a bit after the car is off.

Anyways, we open it up and see some fluid around the top of the coolant reservoir.
Let it cool down and then proceed to take off the reservoir.. The nipple on the top of it had cracked and could be pulled off by hand. We go to Bap-Geon and get a new reservoir, install it and then run it down the street. Starts to overheat again..

We couldn't find a leak anywhere in sight.. I then find some sensor hanging down and touching the plastic under body. WTF?!?! I clean it off and then search around for what it could have fallen off of. Put it back in place and drive it down the street. (It mounted on the housing to the fan, appeared to be a heat sensor.) Drove it down the street and it would get near the white line to the right for about 7 seconds and then drop back down to the center.

My 'down the street' is about 5 miles going 45mph, and in that time after i put the 'sensor' back it would only go towards the white line to the right twice on a test run.

Now the new reservoir has sprung a leak, apparently the glue used to keep the top on didn't seal all the way around. Losing about half of the reservoir fluid a day. (After test runs and stuff, and then leaving it to sit till the next day)

Tomorrow I'm taking back the "new" reservoir and getting another one. Going to install that, jack up the front and take off the plastic underbody which has a nice amount of crud on it now.. -___- Then check for any leaks anywhere else.

Wondering if the reservoir could be leaking this much, or could I possibly have another leak somewhere..
Anyone had any problems like this??
Definitely disliking my car right now.. -___-

-Nathan

[PresaMat]

Huh? English please.

[N54YO]

I don't think anybody can understand what you just wrote to help you man...

[wj4]

Damn, this is not AIM, man.

[Expired]

Uhhgg..
#1 BMW starts to overheat while driving it for around 10 minutes.
#2 Check the engine bay the next day.
#3 Find that the nipple on the cooling reservoir is cracked and obviously leaking.
#4 Replace the part and it is still overheating.
#5 Find a sensor hanging and return it to the housing of the fan between the engine and radiator. (Apparently listed as an AC cooling sensor or something in parts stores)
#6 After a few 5 mile runs the temperature then would rise to the white line to the right just for a few seconds, and then come back down to normal. (It would only rise twice on a run, so we figured the sensor had something to do with it)
#6 I then noticed that the reservoir level had dropped, and we didn't know where the leak was.
#7 We then found that the glue used on the reservoir didn't seal all the way around and was leaking.
#8 I have another reservoir now and I am going to install it again today.

Could the reservoir alone be leaking half of the reservoirs coolant in one day alone?? Or could it be in combination with another leak??
Could that sensor be the reason that it was overheating?? (I guess I will find out after the leak is fixed..)

-Nathan

[Ryan@Motorwerks]

if your car is still under warranty, plz just get the dealership to look at it...

[PresaMat]

Originally Posted by 335e90

if your car is still under warranty, plz just get the dealership to look at it...

+1000

Also... when stating my BMW is overheating that tells us very little. Are you running a 08 m3? a 1985 318i?

[footie]

What miles are on the engine and also have you ever driven it that hard that it's over heated at a time. If it's not a sensor it sounds like a warped head, I did something similar to an Escort RS2000 and the thing kept overheating until I replaced the head.

It only a guess but either way you will need it looked at before some real damage is done, if not already.

[Expired]

Originally Posted by footie

What miles are on the engine and also have you ever driven it that hard that it's over heated at a time. If it's not a sensor it sounds like a warped head, I did something similar to an Escort RS2000 and the thing kept overheating until I replaced the head.

It only a guess but either way you will need it looked at before some real damage is done, if not already.

50,3XX
Nope, I baby it.. IIRC it started to overheat 1-2 days after a drive home from Dallas.
Hopefully it is nothing serious or costly.. -___-

Originally Posted by PresaMat

+1000

Also... when stating my BMW is overheating that tells us very little. Are you running a 08 m3? a 1985 318i?

'01 530i

Originally Posted by 335e90

if your car is still under warranty, plz just get the dealership to look at it...

I was hoping to avoid the dealership with a minor fix, but now I'm taking it in tomorrow.. And it isn't under warranty..

-Nathan

[335xi]

One of the most common problems in the e39 5-series is the plastic end-tanks of the radiator cracking. On my 2001 540 the radiator was replaced after about 50k miles.

My 540 suffered from the two most common e39 5-series problems, cracked radiator end tank and bad fan speed resistor.

Why are you asking this question on this board, there are a number of e39 boards that would be far more helpful.

[Expired]

Originally Posted by 335xi

One of the most common problems in the e39 5-series is the plastic end-tanks of the radiator cracking. On my 2001 540 the radiator was replaced after about 50k miles.

My 540 suffered from the two most common e39 5-series problems, cracked radiator end tank and bad fan speed resistor.

Why are you asking this question on this board, there are a number of e39 boards that would be far more helpful.

Because I like this board, and it's the only BMW forum I feel like being a member of..

Anyways, on the way to the dealership it got into the red again, so I pulled over and popped the hood. The engine didn't feel overheated at all so we figured it had to be a bad sensor or something.. I then started the car up and the temp gauge dropped back down to normal in about 2-3 seconds. We repeated this process about 3 times on the way to the dealership, and we then knew the car wasn't overheating and it had to be a sensor.. Thank god.

They replaced the sensor and didn't find any leaks dealing with the radiator fluid, so all should be well now.

-Nathan

[335xi]

Good outcome, congrats.