1971 John Deere 301 Gasoline Head Gasket

[jcharley]

I have a john deere 301 gas engine, and it has water in the oil and i am assuming its a head gasket. My question however before i start is there anything special i need to know or replace along with the head gasket. Does the head need to be milled, head bolts replaced etc.... Im sure its pretty straight forward but would just like some advice before tearing into it.

Thanks,
Jeff

 

[beenthere]

You really won't know until you get in there... but plan to have the head checked out or just take your chances.

Do you have the service tech manual for that model? If so, you should be able to go forth.

 

[jcharley]

Yes I do, thanks

 

[jcharley]

I'm wondering now if maybe I have a different problem.
Tractor sat out last few months and we've had a lot of rain. I'm wondering if the water came from the exhaust. It has a little flapper on it but we've had record rains the last month. I've changed the oil on it and I'm getting a lot of smoke from the blow by tube. Looks like oil and water. Would this be from a leaking head gasket or possible other issues.

 

[Spanner]

For water to enter the sump through the exhaust pipe it must pass throug the exhaust manifold and into the cylinder(s) with an open exhaust valve(s),

Likely, in that scenario, that you may have stuck piston rings, corrosion or other damage. Removal of the Cylinder Head will help you determine the extent of the damage (if any).

Or you could employ one of those endoscopic inspection cameras, with a bendy tube, through the spark-plug hole.

 

[jd110]

Have you been losing coolant? If coolant is staying full and water is getting in oil, then through the exhaust is a possibility. Another possibility is leaking cylinder liners. The engine has wet sleeves that could have leaking orings or have cavitation damage on liner sides. In my experience, there is a higher likelihood of liner problems than head gasket but anything is possible. How much water/coolant is in the oil? Is there any sign of oil in the coolant?

If you are losing coolant, I would recommend removing the oil pan and doing a pressure test on the cooling system to pinpoint where the coolant is getting in. If you see coolant coming between piston and liner, rotate the crankshaft to get piston near the top on that cylinder. If caused by cavitation, you should see coolant coming through the liner an inch or so from the bottom.

 

[jcharley]

yes i have been loosing coolant and has been running hotter than it used too which is why i suspected head gasket. i havent seen any oil in the coolant yet but it was about 1.5 inch below the fill neck and looked green still. the oil had what i would consider a lot of water in it. it was almost sludge like and it had a fresh oil change just a few months ago. also the oil was still clean when last parked about a month ago. however im new to tractors so wasnt sure what i might be getting myself into. i will try to get the pan pulled and and coolant pressure test done on in tomorrow. thank you for pointing me in a direction.

 

[jcharley]

I warmed it up this evening and did a compression test on it. The cylinders 1, 2, 3, were 155, 80, and 145.

 

[jcharley]

I did a leak test on it today and I couldn't find any coolant coolant leaking from around the pistons. I did find a loose hose however. I'm fairly certain that the water got in from the stack. HOWEVER I did find bits of metal in the pan, looked like pieces of a ring and after looking closer at the number 2 piston I found that it was cracked and that explains the low compression and I'm guessing the enormous amount of blowby I'm getting. Now I have more questions. I'm not afraid of tearing into this motor it seems pretty straight forward. However I would like to know if there is anything I should be looking for and if you could help me locate the proper rebuild kit as when I'm looking I see there are several variances. Also should I do an out of frame or would an inframe be sufficient.

It's a john deere 301 with serial number 127062T

Thanks again,
Jeff

 

[Spanner]

I can't help you with parts suppliers etc. from here, but I'm glad you found the causes of your problem.

In/Out? kind of depends on your Main Bearings.