Coolant Leak

benben

Member
So there is a small crack on the plastic tank attached to the radiator which is leaking coolant. The Mechanic wants me to replace the whole radiator which is like $350 plus labour and coolant = $550
Is there a cheaper alternative? for the meantime he has put some araldite on the crack to seal it for now but obviously this is not a permanent fix.
 
Sounds like you just need to replace the coolant expansion tank. If you search on here its quite a common failure but will certainly be cheaper than replacing the whole radiator.

Andrew.
 
If the expansion tank has gone then it is likely the rad isn't too far behind. Take a look at the bottom of the rad and see if it is banana shaped. If so then your going to want to do both.

Its a fairly simple DIY though if you are handy with spanners. :thumbsup:
 
Over time the plastic of the tank degrades and can crack, some are getting on for being 12 years old now so it isn't always an indication that anything else is at fault. Quite a few people on here have replaced their expansion tanks without any issues with their radiator.

Andrew.
 
I replaced mine a couple of months ago (on my old Z4 - long story). It can be a PITA, but there are some good 'how to's' on the E46 forums (same rad set-up). I also posted my experiences on here viewtopic.php?f=3&t=63416&p=936393#p936393 as the E46 coolant tank from Meyle is a direct regalement for the E85 one, although Meyle themselves don't list it as such. It took me about 3 hours to remove and about an hour to fit (plus refill teh coolant and bleed), although most of the removal time was kid gloves trying to remove the tank from its bracket (bottom o ring is a really tight fit) when more force, albeit controlled was required.

There is definitely no need to replace the radiator (which is aluminium I believe and should last way beyond the expansion tank).

Give it a go, not difficult, just time consuming.

Cheers, James
 
simonlpearce said:
If the expansion tank has gone then it is likely the rad isn't too far behind. Take a look at the bottom of the rad and see if it is banana shaped. If so then your going to want to do both.

Its a fairly simple DIY though if you are handy with spanners. :thumbsup:

Completely agree.

DIY all the way :)
 
Thanks for the advice guys, the mechanic reckons I can just replace the tank too but he says there is a rubber seal or something that goes around it and you gotta send it to some factory for them to press it...
is this true? or can the tank be separated from the radiator without big drama?
 
I have completed this job recently ,the expansion tank can be replaced without much drama it can be a bit stubborn to remove and need a sharp tap from the bottom with a mallet .There is a rubber seal on the base of the expansion tank but it just press fits onto the radiator no special tools needed .

1. Drain the system
2. remove all hoses and connectors the one on the bottom of the tank is awkward and your working blind it slides out
3. tap on the bottom to remove the tank and wiggle it out
4. swap the low coolant sensor to the new tank
5. fit the new tank by pressing hard into position and attached all hoses and clips
6. top up with coolant from BMW and bleed the system


the whole job takes approx 1.5 hours ,and the part costs £80 from BMW dealer
 
Back
Top Bottom