How bad is this?

C

CryptoWhale

Member
So to add to my never ending list of issues with my car and bottomless pit of money I have spent on fixing things, driving today temp gauge shot all the way up to the red light. It kept shooting up and then down to the center again when taking the car above around 2.5k, I could also hear the radiator fan being activated (i think) when the gauge kept shooting up.

There is now the coolant top up light lit up on the dash board. Just looked under the hood and it appears there is a leak?

Could this be somthing serious and costly? Car is currently sat on the driveway will I be okay to drive it to the garage?

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i had something similar, took my car to my indy and he performed a pressure test on the expansion tank and tested the radiator cap, found the issue went away after replacing the radiator cap. I would get a pressure test performed on expansion tank, i had waterpump and thermostat replaced about 6k miles ago so they were not high on the suspect list.
:thumbsup:
 
bigwinn said:
I’d be guessing expansion tank as a starter for ten
Click to expand...
I'd head the same way.
Pressure builds up, the crack opens and coolant escapes, pressure drops causing coolant to boil and up goes the temp.
But then the lower pressure allows the crack to close a little, combined with the fan kicking in, and the leak stops.
Pressure builds up, the crack opens..........

Best bet is get the bottom tray off, run the car up and get under with a torch. Easier to see where the leak is starting from.
In fact, on mine it wasn't the tank cracked, but the O-ring seal at the bottom was flattened and leaking. To change that it's tank out, so may as well fit a new one anyway.

Can't remember whereabouts you are? Maybe near someone who could save you the garage costs??
 
enuff_zed said:
bigwinn said:
I’d be guessing expansion tank as a starter for ten
Click to expand...
I'd head the same way.
Pressure builds up, the crack opens and coolant escapes, pressure drops causing coolant to boil and up goes the temp.
But then the lower pressure allows the crack to close a little, combined with the fan kicking in, and the leak stops.
Pressure builds up, the crack opens..........

Best bet is get the bottom tray off, run the car up and get under with a torch. Easier to see where the leak is starting from.
In fact, on mine it wasn't the tank cracked, but the O-ring seal at the bottom was flattened and leaking. To change that it's tank out, so may as well fit a new one anyway.

Can't remember whereabouts you are? Maybe near someone who could save you the garage costs??
Click to expand...

Aye- I've got replacement of these down to a fine art now!

Experience says at best you'll see a fine mist rather than a raging torrent
 
I didn't have the temp fluctuations but I wasn't driving it very far and topped it up when the light went on. BMW coolant isn't the cheapest so got it looked at by my local indy who relieved me of £250 for the privilige. They pressure tested it so confident that was the issue. It's an item that seems to go pop at some point so if you wanted to get the spanners out it's not wasted money/effort if it turns out to be something else.
 
So upon making this thread and leaving the car parked on the driveway it was in fact leaking and I came out to a small puddle of coolant on the driveway. Took the risk and got it to the local garage which is 2 mins drive as opposed to my nearest Indy which is over 10 miles away. They have confirmed it is the expansion tank. Quoted me £105 + fitting. Not sure if that is the going price but I am happy it's not water pump territory.
 
enuff_zed said:
bigwinn said:
I’d be guessing expansion tank as a starter for ten
Click to expand...
I'd head the same way.
Pressure builds up, the crack opens and coolant escapes, pressure drops causing coolant to boil and up goes the temp.
But then the lower pressure allows the crack to close a little, combined with the fan kicking in, and the leak stops.
Pressure builds up, the crack opens..........

Best bet is get the bottom tray off, run the car up and get under with a torch. Easier to see where the leak is starting from.
In fact, on mine it wasn't the tank cracked, but the O-ring seal at the bottom was flattened and leaking. To change that it's tank out, so may as well fit a new one anyway.

Can't remember whereabouts you are? Maybe near someone who could save you the garage costs??
Click to expand...


Not the most mechanically minded but that makes perfect sense, turns out it was the expansion tank. From what I have read it doesn't look like too big of a job but I need the car back on the road ASAP so for convenience I am just going to let the local garage sort it out.
 
Well that's probably a tad high for an expansion tank, but then you're paying for the speed of delivery and getting your car back.
Not an automatic is it?
Just that they have an extra oil cooling thermostat that the expansion tank sort of sits on top of. From experience they fall apart in quite spectacular fashion as the plastic gets brittle and there's a 'kin big spring inside.
So If it IS an auto, tell them to have a new thermostat to hand as well, just in case.
 
CryptoWhale said:
So upon making this thread and leaving the car parked on the driveway it was in fact leaking and I came out to a small puddle of coolant on the driveway. Took the risk and got it to the local garage which is 2 mins drive as opposed to my nearest Indy which is over 10 miles away. They have confirmed it is the expansion tank. Quoted me £105 + fitting. Not sure if that is the going price but I am happy it's not water pump territory.
Click to expand...

I replaced mine myself just over a year ago. I bought an eBay one (£25 ish) with a 2 year warranty and ISO numbers + OE quality. So a quick cheap fix.
It failed again not long ago. This time I let the local Indy do it. They bought it from BMW which was over £90 so your quote seems right. Came in at £170 all in. I was expecting more TBH.
 
Picked the car up today.

£110 expansion tank
£15 antifreeze
£80 labor

...not including VAT :(

Including VAT total came to £246. Got a feeling that this more than what an indy would have charged :thumbsdown:
 
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