1939 U engine questions blowing oil

Tully123 · Jan 3, 2019

Hello, I posted several months ago about bringing home my Grandfather’s 1939 U. It hasn’t run in probably 50 years. After puttering around for months my friend and I finally got it to run over the long weekend. It was very rewarding.

The problem I am having is that it burns and blows a lot of oil. More than I have ever seen. The shop has drops of oil all over everything. Still worth it!

What would be the best guess on the problem? Rings? Valve guides? Just looking for some direction before I tear into it.

Thanks for your time.

rustred · Jan 3, 2019

rings are most likely stuck. add a quart of mystery oil to 5 gallons of gas and then hook it to some machinery and get it working hard and warmed up. work it for a few hrs. need under hard pull to loosen the rings. idling around will do nothing.

X-Y switch · Jan 3, 2019

half a cup of ATF in the cylinders for about a week might be worth trying, the rings must be really stuck to be blowing oil out like that.

X-Y switch · Jan 3, 2019

half a cup of ATF in the cylinders for about a week might be worth trying, the rings must be really stuck to be blowing oil out like that.

Rich'sToys · Jan 3, 2019

And that's not surprising if it's actually been sitting that long. I'd try the ATF also.
Otherwise, keep running it and see if it comes out of it. You can always tear it down if nothing else works.

Tully123 · Jan 4, 2019

Thanks for the responses and ideas. In my puttering around with it I had been squinting Marvel mystery oil in the cylinders to soak them. Looking at the
inside of the exhaust manifold shows a lot of old oil caked in there. I don?t know if that is normal or showing that this condition existed before it was
parked.
I will try some ATF in the cylinders and see if that makes any difference.
When we started it we let it run at above idle for at least 30 min. I didn?t hear any knocking or excessive valve noise, I was very happy about that.
I am new to working on tractors. If I need to change them are there ring sets available for this tractor?
I tried to link the start up video if anyone is interested. https://m.youtube.com/watch?v=DcprxwpMtgk
Thanks again.

molinegb · Jan 4, 2019

Sound like motor worn out Has be reason manifold caked.

Dennis P · Jan 4, 2019

I have had issues with industrial LP Mazda engines that, having set for a while, the rings would stick & not have enough compression to start. I oil the cylinders to fire it off, let it get hot, shut it off, change oil, & add a quart of Marvel Mystery oil (Rislone works also)to the crankcase. This fixes it & no more issue of rings sticking.

JOCCO · Jan 4, 2019

If it sat for 50 years I tend to agree rings stuck. A simple rering and hone the blocks should not be to hard or costly.

Tully123 · Jan 4, 2019

Thanks again for all of the responses. Any ideas about the best place to get new rings?
I am going to soak the cylinders again and try that first, but want to start looking for replacements if needed.
Thanks

rustred · Jan 4, 2019

yep, you will get better results working the heck out of it than just pouring atf in cyl's and hoping. you need the compression to drive the rings outward. mystery oil is an upper cyl. lube and that's what u need.

sms · Jan 5, 2019

Some years ago I got rings for a U from Agkits.com Also the go to for MM
parts is Welters Farm Supply.

molinegb · Jan 5, 2019

Rings common. Have NOS pitons (3) guides and intake valves. Might have rings if not can
supply.

Tully123 · Jan 5, 2019

Thanks for all of the responses. I would love to take it out and work it hard, unfortunately winter and tires that will disintegrate if I did anymore that slowly pull it out of the shed are preventing me from doing so.
I will try soaking the cylinders again and running it in place and see if that makes a difference.
Thanks again.

rustred · Jan 5, 2019

even if you could belt it to something to get it working. also cover the radiator with about a 6" round hole in fan centre. want it to get pretty warm but not boiling. even do a compression check on it. it could have been possible the tractor was never worked hard and its carboned up. also spraying(misting) water into the intake will help loosen the carbon. how's the spark plugs look? black and carbon fouled? plus its possible to that's its just worn out.

Tully123 · Jan 5, 2019

Well, I got it started again today and had it running for about 15 minutes with the radiator partially blocked. I noticed the oil leaking out of the fill cap was white so I shut it down.

The oil in the case was white and milky. This is telling me head gasket or cracked coolant passage. Anything else it could be?

Looks like I will be pulling it apart for sure now.

Thanks

larry Mi · Jan 6, 2019

It could be your water pump seal after setting all those years.

JOCCO · Jan 6, 2019

Oil and coolant could be mixing there are numerous tests for that. Did you get all the water condensation out of it after setting?

rustred · Jan 6, 2019

did you drain the old oil and have new oil in it before starting? kinda the first thing is to crack the drain plug at least to check for water.

Tully123 · Jan 6, 2019

After noticing the problem I drained the oil and water from the case. I will rinse it with MMO soon.

Before starting the tractor I drained what little oil was in the case, cleaned the sludge from the bottom and the screen for the oil pump pick up and rinsed the case as much as I could with MMO. The case was as clean as it could be. I filled it with fresh clean oil. The oil that turned white had about an hour run time on it. I am new to tractors but not totally wet behind the ears :wink:
Thanks for the replies.

JOCCO · Jan 6, 2019

Tully let me know if you need any help on testing for issues of leaks.

rustred · Jan 6, 2019

ok, very good.if the original oil was black and dirty then u possibly have a leaky water pump. also has the tractor been sitting with anti freeze in it or a dry block. im thinking dry.then when u added coolant it found its way past a dry seal.

Tully123 · Jan 6, 2019

Jocco, Thank you for the offer. I will take all the help I can get.

Rustred, The tractor sat dry, which i thought was probably a good thing, but it sounds like that may have caused some seal issues.

The help and ideas are truly appreciated.
Thank you.

JOCCO · Jan 7, 2019

Tully do some research online but 1. you can make or buy a fitting for the radiator. Take cap off make sure its full, use old inner tube and valve stem and attach with hose clamp. Put some air presser to it (not a lot a few pounds) See if coolant is going in the base etc. 2. Take old spark plug and put air fitting in it put in cylinder make sure valves are closed add air. If radiator bubbles, well not good. You can test your valves and cylinder leak down on this one too. If air comes out the intake you have bad intake valve. Hope this gives you an basic idea of course there is a lot more to it. AND THOSE U'S HAD 2 ENGINES a straight block and a split block.

Howard H. · Jan 7, 2019

Did you have a chance to mess with your tractor over the weekend??

I'm curious if running it hard helped any.

Also, what did the air breather look like?? I've found engines with not so much as a drop of oil in the bath, which can give an indication of the sort of treatment it had.

Howard

1939 U engine questions blowing oil

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