Ford 9N Oil in Coolant

Rockfootball47 · Aug 5, 2014

I have a 1942 Ford 9N that I've had for about 4 months now. I've noticed that it's been using a lot of oil, maybe 1 qt every 3 weeks when running about 8 hours per week give or take. Initially I attributed it to burning it up because the exhaust was leaving black residue on all of my attachments. But now I'm thinking it's leaking into the coolant. Everytime I stop my tractor it will eventually leaks a black and gray sludge from the radiator overflow drain pipe. First I flushed the radiator with regular water until it ran clean and refilled it. When it kept happening I figured maybe it originally leaked and someone just filled it with the radiator hole plug stuff since the last owner replaced the water pump.

What are your thoughts?

Please don't tell me the block is cracked.

Soundguy · Aug 6, 2014

black exhaust is usually 'rich' fuel setting.. check your carb main needle setting.. may be too much open.

as for the grey sludge.. since there are no oil passages in the head, it could be 2 things.

1, it really could be worst case and a cracked block..

2, more often it is a slightly leaking head gasket that is pushing combustion byproducts into the radiator making an oily film emulsion.

since a head gasket costs 20$ and a new block costs way more.. i'd start with the head gasket.

drizler · Aug 6, 2014

Most likely a leaking head gasket. These things are so easy to do you probably should just go and switch it out. Very cheap for the parts too. Once you get them right you just can't kill them unless you run them dry or let the block freeze. You could do a compression check or a radiator pressure test and possibly learn more but with one of these babies you are probably better off just doing a quick head gasket swap and be done with it (hopefully).

Rockfootball47 · Aug 6, 2014

Thanks guys. I'll try a new head gasket first. I guess I figured a cracked block was less likely since it runs fine and oil pressure was fine.

I had no idea black exhaust was caused by rich mixture. I guess I figured it was just burning a little oil since it was black and the level kept decreasing.

Soundguy · Aug 6, 2014

black oily plugs are burning oil

white ashen plugs are lean

black dusty plugs are rich ( fuel )

tan plugs are perfect!

100% cleaned plugs are steam cleaned.. and there is a leak in that cyls combustion chamber

drizler · Aug 7, 2014

For what's involved $$ wise it might be a good idea to give the old girl a tune up. Plugs, points, possibly even wires and surely a cap and rotor. Then you know what is good (usually) and bad. Black exhaust usually means running rich which usually doesn't hurt anything. Check those plugs and see which one is super clean, that will be the source of the head gasket leak.
Don't be too quick to sweat a low cyl and go for rebuild kit for engine either. I bought my TO 20 with it's Continental engine in 94 burning oil badly blowing black blue smoke. I tuned it up some and ran it reasonably till now. It still has less than 90 in #2 last time I checked and it has had a slight knocking bearing the last 3 years. I use it gently and just mow the grass in my yard with it and it gets a full rebuild this winter. Prior owner couldn't figure out why it wouldn't brush hog 4' grass with a 5' deck in 3rd gear. I mowed mine with a 5' deck, 10 acres in second and sometimes 1st for many years now. A lot of it comes to taking it slower with higher RPMS and taking it easy.
Also don't get ideas of hanging a loader on the front of that thing because it has brittle bones in the nose. It just wasn't made to carry weight up there and with no power steering it is close to useless. Get it right and treat it right it will far outlast my new Massey 3617.
You really ought to do a compression test on those cyls to get an idea what you have though. It, like the shiny spark plug will tell you where to look to see the leak in the gasket, crack in head, ect. Sometimes those little critters can be hard to see even if you know what you are looking for and where to look. Good luck.

Rockfootball47 · Aug 11, 2014

Update time.

I tore down the engine this weekend and think I found the problem. There definitely appeared to be a leak through the head gasket at the two main water passages in the middle and they were leaking into the valve area. There was actually pitting/corrosion around that area on the head probably from the water over the heads. Minimal but still present. Hopefully this wont affect the compression. When putting it back together we determined it was caused by the head not being tightened down good enough because one of the studs stripped at less than half the required torque spec.

Where can I find these replacement studs/nuts? Does Napa carry them? I'd rather not have to buy them online, b/c $4.50 a pc on line is just crazy to me.

Soundguy · Aug 11, 2014

dealer has the replacement bolts.. can also likely find them at a bolt store

what are you going to do about the stripped hole? drill, plug, redrill and tap, or drill, tap, thread insert?

Soundguy · Aug 11, 2014

dealer has the replacement bolts.. can also likely find them at a bolt store

what are you going to do about the stripped hole? drill, plug, redrill and tap, or drill, tap, thread insert?

Rockfootball47 · Aug 11, 2014

I didn't explain that very well. The thread portion of the stud that the nut goes onto is what stripped. So the nut just kept spinning. I did have a problem with another nut that seized and ended up unscrewing the stud out with it. I was planning on using some Loctite (probably Blue) with a replacement stud when I put it back together.

I do have a Ford dealer within about 45 mins of me, but was hoping NAPA would have them to save me the trip. I swore I remember reading somewhere online that they did.

So in all, I want to replace two studs. How should I know how far to screw the stud into the block?