1. compression test, depending on the engine it shold be around (above) 150
on all cyl. anything below and vastly different then other cyl. may indicate
blown head gasket, worn rings, bad valves. To verify for ring issue squirt
less then tablespoon of oil into the suspected cyl. and redo the test, if
better then rings are worn
2. cooling system pressure test
3. vacuum test, may reveal head gasket, valve issue etc.
4. cylinder pressure test
5. thorough ispection of s.plugs (if different then others = suspect,
especially if cleaner (washed) or rusty

Inspect the engine block for cracks (rust, pealing paint) around the block
drain plugs, remove the oil filter and check for water.
Possible reasons:
cracked engine block
damaged head gasket (or loose)
damaged intake gaskets
water entering through the carb/intake (rain water)
internally cracked raisers/exhaust manifolds
bad raiser or its gasket

Keep an open mind, it doesn't have to be the most expensive (to repair)
reason.


wrote in message
...

I checked out my Volvo 4.3L (275 hours) for the first time this
season. Ran the engine for a few minutes and checked the oil. It was
milky white, apparently mixed with water. The last thing I did at the
end of the season was change the oil, haven't run it since then.

Changed the oil, ran for a minute, checked again. Milky white.

My guess is something froze over the winter. Is there anything I can
check that I could possibly fix myself, or should I just bite the
bullet and take to a mechanic?

A friend suggested a running compression test. It's too dark now, I'll
do that in the morning.

Any other diagnostic suggestions?

Thanks,

Terry