tearing out what is left of my hair, 2000 V70 XC: P0442 Topic is solved

[Rocket99]

Cooant in reservoir is one inch higher than when its cold.

It is called an expansion tank and for a good reason. Things expand when they warm up and contract when they cool down.

So so true however I have never seen coolant in this car change much from cold to full heat. Until recently. Short after observing coolant level a good inch below the horizontal seam in the "dealer" expansion tank. After topping up to "full " level then drove , got it up to normal running heat and the coolant level was then a good inch+ above that horizontal seam which is upper level I think. Prior to that during the year I drove this car (following replacement engine install) I never saw that kind of change in coolant level between cold and hot.

I rented a car (Dodge charger very nice) for a trip SF to san diego because I do not see a convincing explanation for that high coolant level . ONe of you generous folk did say maybe an air pocket, ie the air will expand more than the fluid. Perhaps coolant prior to refill it got so low it sucked in air( I do not know how it flows ie can it suck in air.?

Due to overall stress I cannot chance a breakdown, SF to SD there are hours of nothin in between . LA to san Diege its freaky densely built up.

[Rocket99]

Ill consider this topic solved when the recent oscillation of coolant in return tank, from one inch low to 1 plus inch high, is explained

Now it is stable with minor rise between cold and full temp. It is obviously sinister though and only reliable around town.

I guess the 1.5 year saga of finding and swapping out the engine shortly after aquiring this otherwise very nice car

I admit i have a brain the size of a pea and just lately its become one of those shriveled up dried peas

Anyone ever had the pleasure of a medication called lupron?

[volvolugnut]

Try a cold pressure test on that coolant system. Obtain or build a pressure adapter for your coolant cap. (You can drill and tap an old cap to install a 1/8 pipe nipple and low pressure gauge.) Use a low volume pump, like a hand pump, to pressurize the coolant system to the normal pressure limit of your regular cap. Watch the coolant level as you increase pressure. If you have an air pocket, you should see the coolant level go down significantly.

volvolugnut