split coolant tank? just 2.5 years old...

[David.X5]

Got the low coolant warning today driving home with the kids. Late and cold out, so didn't want to wait for a flatbed. Engine temp was normal. Stopped at the nearest shop and bought a gallon of premix 50:50 coolant and added about 1/3 gallon to top off and made it home.

It looks like the classic leak from the coolant tank seam. No residue from the cap down to the seam, then lots of residue from the seam on down.

Anyone think otherwise?

FWIW, it is a Behr tank that is 2.5 years old. Always had the reduced pressure cap, too.

[Joshdub]

Looks failed to me

[StephenVA]

Known weak link in our cooling systems. After replacement, only fill it to the MIN level. It appears some will fail if the extra liquid is added causing a little too much pressure within the expansion tank. One would think the lower pressure cap would release that pressure before it reached a critical point but no.....

I am sure someone will chip in with the actual failure point PSI. The tanks appear to be glued/bonded and assembled rather than a one piece blow mold.
No, lets not start pounding this thread on expansion tank thermo dynamics, metal VS resins & polymers technologies.

[David.X5]

I'm going to buy the BMW version this time ($95). I though the $40 Behr version was equivalent, but I want any tiny advantage I can get.

[StephenVA]

[Rockit]

I'm on my 3rd one. OEM failed...someone put on a Chinese one, lasted a year then I bought OWM. Yes the seam splits.