Coolant leak - expansion tank?

CRAIGO · Post by **CRAIGO** » Fri Jan 18, 2019 3:25 pm

My 2003 3.0i is currently parked at work having driven in this morning. Walking past this afternoon, I noticed a very small 10cm patch of coolant directly under where the expansion tank lives. I can’t strip off the radiator cover now but I’m assuming the expansion tank has developed a very small crack through heat cycling.
The coolant gauge still shows as full so I think I’ve caught this in time!

1. I assume it’s safe to drive the 5 mile journey home, heaters on full and taking it easy judging by the minor coolant loss?

2. If it is the expansion tank, can anyone recommend a suitable replacement?

I’ll also need coolant which service history shows was changed in April by a BMW Indy. I plan to top up rather then drain the entire system so what coolant is recommended?

Many thanks

unknownz4 · Post by **unknownz4** » Fri Jan 18, 2019 6:03 pm

Not sure if you're looking to replace it with a OEM or aftermarket, but I had good luck with https://www.redlineautoparts.com/bmw/ guys for used OEM parts.

mjennings23 · Post by **mjennings23** » Fri Jan 18, 2019 8:53 pm

Dont buy cheap crap. Hella are the OEM I believe and you can get Hella branded tanks for around £40.

ECP sell them, but youll have to put vehicle details as an E46 3 series as they dont show up under Z4s for some reason. It's the part I have fitted so believe me, its the same!

patriot66 · Post by **patriot66** » Fri Jan 18, 2019 11:13 pm

I fitted a Meyle HD one. Super OEM quality, 2 year warranty, went in easily and no problems since. I have fitted many FEBI Bilstein parts to my Zed which I think are excellent so would think their tanks are also good. IIRC when removing my original BMW one it was a Behr so they are probably fine too.
I have had Comma Xstream G48 coolant in mine for 4 years now

: 20190118_220614.jpg (71.29 KiB) Viewed 594 times

CRAIGO · Post by **CRAIGO** » Thu Jan 24, 2019 9:16 pm

Thanks guys, I’ll get one ordered.

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