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Hey Everyone, I`ve only in the last 2 months became a L-series EA82 MPFI wagon owner. My problem is everytime I run the wagon on med - long trips and switch the motor off the coolant goes to the overflow bottle (thats normal).HOWEVER it never seems to return, and the more i use the wagon through the day stop-start-stop-start it slowly emptys my radiator - therefore leading to a hotter than usual motor. Ofcourse i have cleaned the overflow bottle out, and the over flow hose is not abstructed, replaced radiator cap and made sure it was the right one? Got me beat!

If you run the engine with the radiator cap off, are there any bubbles visible surfacing in the coolant?

This sort of behaviour can unfortunately indicate a head gasket leak, which our favourite engines are prone to develop.

or a blocked radiator core?

My wagon due to the constant filling required of the radiator does have water bubbles when filling (they would be air bubbles that are normal when fillling). As for the radiator i have flushed it out and it seems to drain freely. My main problem as mentioned above is that the overflow bottle will not return the coolant back to the radiator.

Have you got any hoses that have a very small leak?

No coolant leaks - only from overflowing overflow bottle (as desribed above)

I got the same problem. Turned out to be a leaking heater core and a blocked radiator.

Doesn`t seem to be a leaking/faulty heater core, i will check water bubbles in radiator and also see how well the cooling system is circulating in case the radiator is slightly blocked as mentioned in the above replys. Thanks

i bet it is a leak too, might be very tiny atm, possibly near the top of the radiator.
When the coolant cools, the vacuum produced pulls water back from the overflow bottle - with leak - no vacuum - hence what you got....

anyway, the hole will get bigger, trust me.

Sounds to me like you need to pressure test the radiator.

Like Jack said, a professional pressure test should also test for head gasket leakage(hydrocarbons in coolant).
Daza.

Yes a pressure test would be a good idea and as for a leak? could be an internal leak? The radiator does have a lot of coolant pressure though - try removing the cap after you have turned off the motor (when its warmed up) - that may indicate something who knows?

or a hose clamp allowing thinner- than- water air in to replace water volume, or maybe a hose that sucks in on itself (don't try that on yourself !)

Is it starting from cold running on 3 cylinders?

If not its probably a blocked radiator or heater core

Its running on 4 cylinders when cold, does chuckle for a couple of seconds when you start it (dead cold), also i guess i could fiddle/ try different overflow hoses/ clamps.

I've had this problem in the past. I'd say if the rad/thermo/heater isn't blocked, a small leak may not push out much coolant, but will easily suck in air when cooling, so not allow the coolant back in. dunno mate. mine used to push out the coolant as you've described, and maintain pressure in the system even after cooling down. course when I put in the new engine, rad, water pump, etc etc it went away.....

A new engine would definetly be the cure and not just for the cooling system problem either!