water in oil, 4.3 merc

see pdf attachment

I'm dealing with something similar. Have you figured anything out yet? I have water in my oil and condensation on the spark plugs. Trying to figure out what to fix. Head gasket? Exhaust manifold?

Note to you

The heads ARE NOT BULLET PROOF!!

The V6 has a very large history of warped heads..

several things to do


1. remove head
2. check for flatness, must be perfectly flat. If you cant do this bring to a automotive machine shop and let them check.
3. pressure check water jackets of heads, If you cant do this then ask the machine shop if they can.... this will show craks in water jacket (s).


This issue is typically caused by overheating..........

If you doubt KGHOST's advice ( I don't)

Start with a compression check.
If all OK, Check that the flaps in the exhaust line are OK, i.e., not frozen, crooked or out of place. This could cause an obstruction in the exhaust line that would encourage water to back up into the engine.

I don't like running engines on muffs, I prefer letting the raw water pump suck the amount of water it wants. In many engines, this means a really big bucket and hose ( garden center planters work well... duct tape over drain holes, remove tape to empty planter) or, in the case of engine mounted raw water pumps, a "T" fitting, a couple of valves and a garden hose into a 5 gal pail fed by a free running garden hose.

Ayuh,.... With the oil level risin' on the dipstick, on the muffs,...
Ya got a cracked block,....
Pressure test the coolin' system, 'n follow the hissin' sound,....

'n sandkicker,.... There's no better way to smoke an impeller than usin' a bucket, insteada a set of muffs,....