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Coolant in oil

3663 Views 26 Replies 8 Participants Last post by  meborder
Assuming that one has a problem that allows coolant to get into the oil, is it possible to run the engine long enough to drive all the coolant out of the engine without creating a milkshake and completely destroying the engine?

reason for asking:
Currently tearing down an engine that had what I assumed was coolant getting into the oil.

the oil level went up, and the coolant level went down. After running it for an hour at idle (needed to use the vehicle) there was a lot of vapor coming out of the PCV and breather which I though confirmed my diagnosis. After running the engine for that hour the oil went from 2 quarts too full to 2 quarts low.

83 k20 350 crankcase vapor

when We pulled the engine the radiator was almost completely empty. Only a quart or two came out when we tried to save the coolant.

upon disassembly, the inside is the motor is shockingly clean. The drivers side (PCV) side is squeaky clean with no signs of moisture. The passenger side (breather side) has goopy stuff in the valve cover and sitting on the rockers and head. Definitely moisture related.

the oil was oil when I drained it. Not really happy oil, but not milkshake at all. Some light brown streaks in the pan but not like I would have expected with showing almost 2 quarts over full.

Liquid Automotive tire Automotive lighting Hood Astronomical object

how can this even happen? I was expecting a full on milkshake in the oil pan.
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The video looks like an old and tried engine with a new air cleaner. Looking at the body I say you either live close to sea water or where they salt the roads in winter.

It all looks like it’s best days are some years ago.

As you already know that engine is ready for a rebuild if the castings aren’t cracked and the journals can be spec’ed.

Dont know who’s piston but clearly it’s cast not forged.

If nothing jumps out saying “bad gasket” you’re going to have to get the castings of block, heads and intake inspected for cracks. Going forward without spending the money to track the source or maybe more importantly to find where the source isn’t would risk all the money invested for a rebuild.

Then again sometimes it’s just less expense and hassle to just buy a crate motor. It is unfortunate for us that GM discontinued the bottom of their new crate motor line Goodwrench engine, That was a good deal to start a performance build on at low cost. Pretty much it was replace the heads and cam with some EBay aluminum heads and change to a mild performance cam and you had yourself a creditable, all new street performance engine for about 2500 bucks

Totally bad news. Possibly a thin wall dry sleeve would save the block.

1 - 3 of 27 Posts