Over flow tank.

[shokenore]

Trying to sort this out in my head before I have to fit a new head.


Symptoms.

Overflow tank full,and coolant level inside of pressure cap low.
To fill back up to pressure cap level it takes about a cup full.
Rear heater disconnected and when level is ok plenty of heat from front heater.

Plan of action.
Check footwell carpets for an damp patches,which would indicate heater matrix leaking.
Take pressure cap off and pressure test system to look for any leaks.(fix any that are found).
Check overflow hose for perishing and replace.
Check pressure cap seals and mating faces.


If all the above appears ok then it would be prudent to change the pressure cap as I have no way of testing that.


Then I assume I am getting into the possibility of replacing the head.
Has anybody got an idea of how long the heads that were changed in Japan should last?

[Albannach]

Change the cap if you're not sure.

Check the coolant first thing in the morning, if the engine is even slightly hot, you'll get low levels in the engine and high levels in the overflow.

[shokenore]

Sorry should have said that I always check the level in the morning.
The fingers crossed approach is for the pressure cap.......

[dazandcaz]

I had similar probs. The hose between the engine and expansion bottle had gone hard at the ends and wouldn't seal properly, it was drawing air back as the engine cooled.

[shokenore]

As we like a happy ending I am pleased to report that after I carried out a pressure test on the system both engine hot and cold ,a small weep on one of the heater hose joints was tightened , carpets and footwells checked for damp patches and no damp patches down there.
Drained overflow tank washed and cleaned and topped up to fill mark with fresh anti freeze , then found the rubber seal on the pressure cap not in the best of condition and a load of scale aswell, so guess it was the pressure cap after all.
New cap ordered.