The Stovebolt Site Forums The Shop Area Engine Shop 1946 - 216 fresh rebuild with issues

I am working on a 1946 1/2 ton model DP. Had complete rebuild done at my local motor shop. I ran it about 8-10 miles before Noticing that the oil level was high and coolant was low. I drained the oil and found I had almost 4 quarts of coolant in the oil. I called my machine shop and I pulled the engine and dropped it off. They ran coolant pressure check overnight with 21lbs. No leaking found.

Can anyone help me understand how this is possible?

If that much coolant found it’s way into the oil system, shouldn’t a coolant pressure test show some leakage?

Might only leak when it hot and running ? Example cracked head or block............

I did think about that but it is very difficult to replicate a warmed engine. I know the head and block were magnifluxed before rebuild and I paid to have several head cracks fixed but you never know. I am also a bit suspect of that oil line for the rocker arms. That was not replaced but it also is not leaking with coolant pressure tests. Meaning air / liquid is not coming out of that copper tube.

I can only come up with thermal expansion or cyclical pressure as reasons for coolant transferring into the oil system. What do the plugs look like? If one is markedly different from the others, then I'd lean toward a head gasket.

I just talked to my engine builder and he says he has some applications where warm/hot testing is mandated but he has never seen where temp impacted results. Meaning if it leaked hot it also leaked when cooled

Did the engine builder magnaflux the head prior to doing the rebuild?

To this point no one has looked at the plugs. Yesterday I asked my shop to pull the plugs and see if there were any obvious signs of a head crack.

The heads and block were magnifluxed before the rebuild and the head had 4 issues. Head was sent out for a costly repair and should be crack free now. BTW what is cyclicle pressure

What did the head gasket look like when the head came off? Any chance you had a gasket failure that allowed coolant to get past the gasket to the oil drainback into the oil pan? I am spit balling a little here because I have never taken a 216 apart but thinking there must be some similarity to how the oil from the rockers drains back to the block through the push rod holes in the head, then to the pan through the drain ports in the block near the lifters.

Cyclical pressure as I intended was to mean the pressure in the cylinder that is a result of the compression stroke as pressure increase, followed by power and exhaust stroke as pressure decrease, followed by intake stroke as negative pressure. If the engine shows solid pressure hold in the cooling system when static and coolant moves into the oil when running, then something has to change between not running and running.

Either way, the head needs to come off for investigation.

The head has not been removed from the engine since the issue occurred. We have been trying to diagnose the issue before disassembling the valve train and the head. I feel I have a conundrum on my hands. If I don’t find the offending issue then I don’t know what to fix.

Air pressure test of 21 lbs overnight showed no leakage and wet pressure test of 32lbs showed no leakage.

I am planning to replace the copper line that feeds oil to the valve train and I might have to pull the head, magniflux again and try that. However that is just changing stuff and spending money because nothing seems cracked with either or we should have pressure leakage on the coolant tests

How much pressure is the radiator cap rated for? I seem to remember a normal 1947 system was a "zero-pressure" type, or at the most, 4PSI. If that's so, a leaky oil line through the water jacket would put oil into the cooling system, not coolant into the oil. The only way coolant could get into the oil from the block line would be gravity flow with the engine not running.
Jerry

I checked the cap and it say .9 which I believe =13lbs. This came with a new aluminum radiator I bought to replace the original.

I haven’t brought this up yet but I did find oil residue in my coolant lines especially when I drained the heater core. I presumed that if I found why the coolant got into the oil I could deduct if it was possible to also understand how oil got into coolant. What’s odd is that when I drained what was left in my radiator I did not see the milky white stuff in that drain bucket. Only spotted it in thermostat housing and heater core lines

Was the crankcase oil emulsified, or was the coolant in a layer under the oil? It would be almost impossible to avoid an oil/coolant mix in the crankcase if the coolant entered the crankcase with the engine running.
Jerry

I took the vehicle for a 5 mile test drive and at that point the temp was good and life was fine. 3 days later I went to set the timing and I noticed that oil level was high but oil was clean. Started it and noticed it getting hot so I shut it down. Rechecked oil and it was milky. Drained it and noticed lots of coolant coming out before the oil. 4 quarts to be exact.

OK- - - - -you've got a gravity flow leak somewhere, and the water jacket line is a definite possibility, but that should have shown up on a pressure test of the cooling system. Changing that line is pretty tricky. You need to cut the old line off at both ends and thread a piece of stiff wire through the remains of it to act as a guide for the replacement line, plus about half a dozen other tricks to assure a good replacement that doesn't leak when you're done. If you had antifreeze in the radiator, now the whole oil system is contaminated, and needs to be flushed thoroughly.
Jerry

It sucks to be me.

I will replace the tube but I’m not sure if I should also pull the head and have it magnifluxed for cracks. It comes down to shooting in the dark because I can’t find a smokin gun

Send me a PM and I'll share a phone number with you. You only get one chance to be successful at replacing the oil distributor tube, and there are a few details you need to understand about it that are best discussed in a 2-way conversation. Some of the resto-ripoff parts vendors sell a kit that has all the hardware you need, plus a length of 3/16" copper tubing. DO NOT use 3/16" steel brake line tubing - - - -it will rust out quickly.

You can pressure test the oil line by disconnecting it at both ends and doing a little creative plumbing to apply air pressure to just the line itself.
Jerry

I wanted to post an update on my coolant getting into the oil.

After pressure testing and vacuum testing the engine with no signs of leakage I took the engine home and ran it outside the vehicle. Ran a garden hose for cooling. After running for less than a minute I had a small oil leak at the oil pressure hole in the oil gallery/manifold. I pulled out the gauge and noticed that pure water came out of that hole. I then removed all water from coolant system and pressurized the coolant system from the rear coolant drain plug. It was then that I heard a leak sound coming from the oil pressure line hole in the block. Not sure if it was blocked by rust or other crud but now the pressure test showed leakage. I am waiting on engine shop now to see if this issue can be fixed.

Jeff63 Good Luck on your fix there hopefully they, or you can drill and cork that up and get a lot of good miles out of it.

Jeff63 Just saw your post about the 4 quarts of antifreeze running out, you'll be lucky if it doesn't get your cam ! Had that once thought I had a headgasket leak all sewed-up. First trip out when I pulled up to the 4 way stop...that special miss when you know a lobe is gone !

I sure hope the cam is not prematurely worn. I don’t have many miles on this engine but I know what you are saying. Speaking of the cam I was told to add zinc to the oil to help with break in.

Update:
I called the engine shop today and they could not find a pressure leak by pressurizing from the thermostat housing. HOW IS THAT POSSIBLE?

They will try to mimic my test where I pressurize at the block drain at the rear of the engine. This is starting to be frustrating!

Drop the oil pan, apply air pressure to the cooling system, and hose down the entire crankcase with bubble soap, using a hand pumped spritz bottle. Walmart has them by the dozen. I keep several around the shop for penetrating oil, cutting oil, glass cleaner, and other stuff.
Jerry

Finally got engine back from shop and there was a small hole between coolant passage and oil gallery. Shop put a tube into the oil gallery and it appears to have fixed the issue. Engine is back in and truck is running. Thanks for all your input