Starting an old tractor in the cold...

[crw]

Been there, done that. But I need to try it again with 30 wt. oil.

As for the coolant, my sense of smell isn't all that great. But, to tell you the truth, it does smell like coolant.

So what would cause all four cylinders to go dramatically bad all at once?

 

[Pop_Rivit]

Originally Posted By: crw
Back to this never-ending saga...

I eventually got to doing a compression test. Big problem... the compression on all cylinders is dramatically low, around 40. Each should be around 90 for it to start.

But then I started struggling with the notion that it started and ran fine last fall, and now, ALL cylinders were so low...

I ran this past a lot of experts on a Ford N board. Nobody had an explanation for it. Then this past weekend I was talking to a friend who said, "Maybe you froze your block. Have you checked your anti-freeze?" Wow.......

You see, this is the first diagnosis that matches the data. It ran fine in the fall, then all of a sudden the compression is way down on all cylinders. Cracked block.

I checked the radiator and the level is about 6 inches from the top. My oil "looks fine", but the level is right on the full mark, and probably more full than I should have expected on this OCI.

So, I'm probably "sorry-out-of-luck" on this one. Is there any way to tell if there is a lot of coolant in the oil, short of paying for anything like a UOA? I'm not in the mood to spend anything more for this, but I suppose doing a UOA might be worth it just to be sure.


Seems to me compression was mentioned early in the thread.

Now, if I have your attention, it's perfectly normal for the radiator on an N to be "way down". Anything over the fins will burp out the overflow when you get the engine warmed up. The radiator on an N will never stay full.

Let me repeat-the radiator on an N will never stay full.

That doesn't mean there is a cracked block.

I'd expect to see low compression on one or two cylinders if the block were cracked, but not all four.

Pull the spark plugs, make note of the position of the plug wires. Drain the coolant (one of head bolts extends into the water jacket). Remove the head bolts with an 11/16 wrench. Note their locations because there are some size differences.

Note the condition of the gasket once you remove the head. Not bad? Ok, next turn the engine over. The valves aren't closing completely, correct? Those little round things next to the pistons (the big round things)?

Take off the manifold, take off the little valve covers, take some cleaner and a brush and clean up the gunk around the springs and valves. Get them freed up and working.

Put it back together and fire it up.

One more question-has the engine been rebuilt in the last 5 years? There was an issue for a while with after market camshaft gears made of fiber rather than metal. They tended to wear out very quickly throwing the entire valve train out of time.

If you haven't had a rebuild in the last 5 years or so then it's probably not an issue.

 

[crw]

Thanks for the tips. I bought the tractor about 5 years ago, but it was from my neighbor at the time, and I don't think it had a recent rebuild.

Question ==> Can I take off the head without removing the gas tank? It seems like it should be possible, but the manual I have seems to suggest that it's necessary to take the tank off.

I did have the side valve covers off... it actually looked nice in there, and everything seemed to be moving properly.

You've motivated me to take off the head. At this point I have nothing to loose..........

 

[Pop_Rivit]

Yes, you can take the head off without removing the hood/fuel tank (all in one), but it will be easier if the hood/tank are off.

The hood is fairly easy to take off-a couple of bolts at the dog legs, a couple for the grill and 4 around the dash. Drain the fuel, disconnect the line at the carb. It's easier if you pull the steering wheel but I've done some and worked the hood/tank assembly off with the steering wheel left on the tractor.

 

[swalve]

does it have any kind of compression release mechanism?

 

[Pop_Rivit]

Originally Posted By: swalve
does it have any kind of compression release mechanism?


No. It's just a simple 4 cylinder flathead.

 

[swalve]

The only thing I can think of that would cause all cylinders to lose compression like that is something like a jumped cam. Maybe the cam or crank sprocket sheared a key or slipped if it's a compression fit.

Or yeah, something cracked in a weird way that affected all cylinders the same way.

 

[crw]

Thanks all... I'll post again when I find something.