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Coolant in oil

3662 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.

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how can this even happen? I was expecting a full on milkshake in the oil pan.
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I’m beginning to wonder if the oil was full of fuel instead of coolant.
This was 4 years ago now that it happened, so some details are not so sharp anymore.

it never smoked, the video shows how it was running. It was cool that day so some exhaust vapor wouldn’t have been out of line.
You would think so.
I did ask him......... crickets ...
If there was a question in your first post, I missed it.

lots of tips on what to look for and I will do all of that when I get back to it. But keep in mind that I pulled this engine years ago and it has been on a stand ever since. So some of the things you mentioned simply won’t apply.

I have to work with what I have.

the video shows a full walk around. You can hear the exhaust cadence and see how it is running.
How can something run for an hour with 1 quart of coolant in it and not overheat?
It was down 2 quarts when I started so I filled it. So it was full at start up.

AFAIK, there are no significant external leaks. I’ve been running everything else the same on the new engine for several years. I don’t add much coolant. The only change I made during this whole ordeal is the radiator cap. The cap that was there probably didn’t build pressure so I put a new 16lb cap on. That’s when the coolant went down and the oil went up. Then I put on a 10lb cap, then changed the engine.

both engines run between 190 and 230 at the head. Thermostat housing and upper hose run at 190, but the head is always above 190 and always below 230.

the real question here is how can an engine run for an hour with 2 quarts of coolant in the oil and not make a milkshake and completely frag the engine?
Sorry, not a direct question . More of a statement about oil consumption/smoking
Thought it might Jog your memory if so..
fair enough. The video shows a full walk around so you can judge for yourself. No need for me to guess, you can see for yourself and advise accordingly.
She is worn out bud.
After watching the video it is painfully obvious that you have EXCESSIVE blow by. Rings are shot.
Probably been overheated too,
Smoking out the tail pipe too.
Cats can oxydize HC pretty well, so when it is warm you may not have noticed smoking as much out of the exhaust as the cat can "Clean" it up
The blow by

Best to tear it down .Be sure to magnaflux for cracks.
Or just keep it around for a beater motor
lots of good stuff here. Thanks for the input.

the smoking out of the valve covers was very alarming. It never did that before so something happened but I don’t know what. The vapor coming out of the exhaust is normal for That time of year. It was in the low 40s and humid. I don’t think one could look at the vapor out the exhaust and say anything other than it was cold outside.

there are no converters. Long tubes into true duals. So if it was blowing smoke you would see the smoke. If the rings were as bad as you suggest the vapor coming out the Back should be very blue.

I’m not saying its not got problems. I think it’s pretty clear that it was unhappy somehow. But I can’t figure out what happened.

the bores look good, at least on the drivers side. The gaskets looked good. I’m confused.

being told it’s worn out isnt Exactly bad news. Just means I didn’t change it for no reason. But from what I can see inside, it looks like a pretty Fresh rebuild, so I’m just really confused.
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well, that much blowby means weak rings
I’m not sure that it is blow-by

Initially I thought it was coolant in the oil and was water vapor coming out as the oil got good and hot.

I’m also wondering if it wasn’t fuel. But I’m not sure how 2 quarts of fuel would have gotten into the oil between uses.

the rings could be shot. Maybe we can tell if they are shot when I pull the pistons?
Got some more tear down completed. The insides look good except all of the moisture. Still can’t figure out where all of the moisture came from. All of the gaskets looked good to me. Might take the block in to a machine shop and have it cleaned and inspected before throwing good money into a bad block.

A couple of questions for the group:

can anyone help me identify these pistons. I’m not reusing them, but I’d like to know if I can just look up the demensions rather than trying to measure them. There is an “M” stamped on the inside of one skirt and “B557” on the other. Any way of looking up what these are? I measured them in the block and they were all about 0.050” down in the hole, making me think they are a low deck rebuilder type piston.

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rod bearing are a Clevite 77 CB663P which looks like a standard diameter bearing?

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the bearings are pretty hammered, but the crank looks good. Just can’t figure out what happened. It went from a great runner to being a rebuild basically overnight.

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Can anyone identify this cam?

looks like

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Also, can anyone help me confirm the identity of these bearing caps?

i think the rods are standard size and the mains are 0.010 under but I’m not sure.

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Well this is a bummer.

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What gets me is that it is at the top side (valley) of the cylinder wall.
Exploring options.

this is really a bummer because everything else looks really great. A simple ball hone gets the other 7 ready to go.

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

Thats the direction I’m looking at depending on cost. Being a 4-bolt block, it might be worth saving.
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