4.2 Coolant Loss
 

Allow me to ask a dumb question.
If I suspect coolant loss,would cranking the
motor with the plugs out show the cylinder being
affected ?
In other words,would coolant show it's ugly head
in some form ?

thanks...Jack

Um. what year motor?

it could possibly, should rather.

Yeah, what model year?
and how many miles?

Doing what you describe might show coolant, and might not. If the loss is very slow, then you might not notice any coolant in any cylinder(s).

A used oil analysis would be a good bet, and maybe a compression/leak down test.

You might also pull the plugs and look for one or two that show a noticeable difference in appearance.

If it were in the combustion chamber you'd probably notice white smoke issuing from the exaust even past normal operation times (After typical condensation would have been..well...exausted). Milky oil would indicate it's in the oil. If both are "fine" than it could also be a loose hose or a heatercore leak.. That's what happened in mine, but again, it depends on how much is leaking and how fast.

Sorry guys.
It's a 2000, 30,000 km on it ...4.2 lt.

Then I'd say a leaking gasket is not as likely as it would be if you had an '97 or early '98, or had 150,000 or more miles.
It IS possible you have a leaking gasket, but not all that common in your situation.

Is the loss slow or pretty rapid?

How long has it been occuring?

If it were me, I'd do a used oil analysis, then you'd know for sure if you were getting coolant into your crankcase.

It is a very slow loss /: 1/2 inch in the expansion tank in about 2months.
Maybe I'm worrying too much !

Maybe NOT worrying too much.

Slow loss over time can damage bearings and lead to problems down the road if the leak is occuring internal.

I'd say a used oil analysis would be a great investment.