Coolant reservoir overflow, low/intermittent heat


New member
Sep 23, 2021
B6 passat 2.0 tdi
This thing is killing me… I have a 2007 passat wagon 2.0tdi 103kw (euro spec) and can’t figure out my coolant issue. Long story short… car will drive with needle dead center… then randomly climb for about 30 seconds, before returning back to center … after this event when I shutdown and open up the hood, it has purged most the coolant out of the expansion tank…

additionslly, heat in the car is marginal at best, oddly the leftvents are better and the furthest righ vent is like air conditioned.
Stuff I checked:
1) heater core flows fine when flushing it…
2) no real bubbles in expansion tank, removed hose from engine and constant return of coolant back into the manifold
3) no smoke or intermixing of coolant / oil

Any help would be greatly allrecieted


Top Post Dawg
Apr 23, 2010
2007 Seat Alhambra 2L tdi
Check the return hose to the coolant tank, see if it has a little plastic restrictor in it and if it's blocked, mine was and caused similar issues apart from losing the coolant, mine all just accumulated in the tank. Heaters went cold, gauge went up and down etc.

Mine is a 2007 seat alhambra with the 2L tdi, BRT engine.