My Tractor Forum banner

21 - 40 of 70 Posts

·
Registered
Joined
·
40 Posts
Sounds like you need a head gasket, assuming that the head has coolant passages in it, doesn't have to be a large leak for coolant to get in. Other wise there is a crack somewhere. A quick check is to pull out the spark plugs and see if one looks like its been steam cleaned or coated in white powder. White and sweet is coolant being burnt. Oil is blue and acrid. Find the coolant leak before you need an engine and stop running it till yu get it fixed, specially if its over heating.

Provided the heads or block surface hasn't warped its a I would guess a 3/5 on the hard scale for the inexperianced home gamer needing a few easy to get special tool to make life much easier. Plan for a weekend to get it done. If you want an idea of what is involved, Mustie1 on youtube has opened up a water cooled JD, i forget what one though.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #22
Orcus79 thanks for the reply. Both plugs are black... not what I expected after reading your post... I think the head gasket is something I'm capable of I'm just not sure I have the patience or the time after performing all the previous repairs. I wonder what it would cost at a small engine shop? Furthermore I don't want to crack into this thing and it end up being something else...
 

·
Registered
Joined
·
4,093 Posts
Looking at the tractor from the front the right head has the coolant temp sensor in it and is prone to leaking in that area. It is not a big job to replace the head gasket but you do have to take care of the valves once you remove the head. Keep all of the rods in the same place so that they will go back to the correct cam lobe. As you go to reinsert the pushrods the hole in the engine end has a lip that you have to go over to seat the rod on the follower. If you don't get it over the lip the rod will appear to be too long to fit under the rocker arm. You will need a torque wrench to tighten the head bolts, and then set the valve gaps which I believe is a 13mm and an Allen wrench for the middle nut. Since you will have the sparkplug out you can use that hole to find TDC. One last thing about the valve cover gaskets. Run your finger under the bottom of the head where the valve cover meets it and see if there is any oil there. I have had some warped covers that could not be sealed and had to be replaced with aluminum ones. When you say "Smoking" is it coming out of the end of the exhaust or just around the engine? When the covers leak the smoke comes from the engine and not the exhaust. Good luck. You have earned some success!
 

·
Registered
Joined
·
39 Posts
Discussion Starter #24
Inspectorudy, thanks for the reply, the smoke is 100% billowing out of the exhaust pipe. You are tempting me to try this myself... afraid I'm going to screw it up further... from watching a video and from what you are saying it seems like there are quite a few parts in the head that could get out of place... The head is right behind the valve cover from what I understand and the exhaust bolts to the ?head?... is there anything else that I will need to remove first in order to get at it?
 

·
Registered
Joined
·
4,093 Posts
You will have to remove the coolant hose from the right head looking at it from the front and of course, the valve cover. After that, take out the sparkplug and the bolts in the head. There are at least one inside of the head and the rest are around the outer edge. You will also have to unhook the exhaust pipe from the head that you will be working on. I believe if you get it apart you can count on help from us to get it finished. When you go to remove the head from the engine take a piece of tape and tape the rods as upper and lower and eng or head end.
That way you won't get them in the wrong valve and the wrong way in the engine. It's not that hard but can be a little intimidating your first time.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #26
Ok, I think I can do this. Do I need to order anything other than the head gasket? Also I was expecting the head gasket to be different side to side since you mentioned that the gasket on the right leaks around the thermostat however I'm seeing that the gasket is the same on both sides. Am I missing something?
 

·
Registered
Joined
·
4,093 Posts
No, the gaskets are the same but there is a thermostat gasket on the top of the head. When you get it off you can take a close look at the gasket to see if any coolant has been leaking through the gasket. It will be pretty obvious if it has.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #28
So I got the head off this morning. Not bad, more work than anticipated having to take the radiator and fan shroud off to get at the bolts but that took only a few min. Now I'm looking at the gasket and I can't tell if it is bad or not. I suppose I should go ahead and replace it (along with the exhaust gasket and the other gasket that goes to a square tube and the carb. If the gasket is ok I feel like since I have it tore down this far I should go ahead and do the other side in case it is the other side and not this side... what do you all think?
 

Attachments

·
Registered
Joined
·
442 Posts
I would suspect the cylinder head on the engine side that had the most fire damage is warped from the heat, leaving enough space where the gasket meets the engine block. There probably wouldn't be must evidence of leakage (antifreeze) on the head and gasket due to the fact you haven't run the engine since the fire. Check very closely any evidence heat related on the head, if there is you might as well replace with a new or used cylinder head. Ebay has used ones time to time.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #30
Nothing good to report, I have now replaced both left and right head gaskets along with the intake manifold gaskets and exhaust gaskets. The head gaskets looked ok to me when replaced. The manifold and exhaust gaskets were destroyed on removal of the head. Smoke is now worse. I only let it run for about 5 min since I was afraid my neighbor was going to call the fire department. I'm at a loss.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #31
Is there any way to tell which head is warped if that is in fact the case? The thing is it only started smoking when I used the low idle stop screw on the top of the carb to force the engine to get up to speed. Since then I can' get the thing to stop smoking even if is back that screw back off and let it idle as it wants around 2700 RPM.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #32
Furthermore how could the head get hot enough to get warped and yet the valve cover which is plastic and closer to the fire has no damage?
 

·
Registered
Joined
·
1,410 Posts
Harlan, First let me say I'm not at all familiar with a 345, so I'm just gonna throw some general comments out!

First, changing a head gasket should not make an engine immediately smoke. Are all hoses hooked up? Check crankcase breather, may have a burnt/clogged "filter".

What color is the smoke? Blue would indicate oil, grey, an over rich mixture, and whitish, antifreeze/coolant.

Idle screw: As I said NOT familiar with the 345! IS the screw on top of carb idle or hi speed adjustment? Typically idle sped is adjusted by a screw contacting the throttle plate arm/linkage.

Last, checking head(s) for warp/flat. It's all got tot come apart! Place head on a KNOWN flat surface...table saw or a piece of glass. Try a .005 feeler all around the head, it should NOT go under. Whatever you're using for a "flat surface" may not be exactly flat. Move head to a different area and check again with feeler gauge. I would think that .005" would be the max allowable for out of flat. Another head of a machine shop can supply you with a flat head. Don't forget to retorque the heads after running for a while...or you could blow a head gasket or warp a head! Bob
 

·
Registered
Joined
·
39 Posts
Discussion Starter #34
rwmeyer, thanks for your imput. The tractor was smoking before I did the head gasket and manifold gasket. The timeline was:

1. Small fire lead to siezed throttle cable, high idle running slow, and surging

Repairs made:
A. New Throttle Cable
B. New Air Filter
C. Clean Carb / New Carb
D. New Fuel Filter
E. Oil Change with Lucas Oil Stabilizer
F. High Idle Adjustment (move throttle plate to the left - helped surging)
G. New Spark Plugs
G. Low Idle Adjustment (caused smoking see below)

After these repairs surging is better but tractor is still running slow ( I was able to artificially get it up to speed by forcing the governor linkage further by screwing the low idle screw (top of carb) all the way in (this artificially sped up the tractor) which is when a new issue occurred: white and sweet smoke, tractor overheated twice and coolant reservoir is full. I tried to back off this screw but the tractor continues to smoke.

Repairs made
A. Head gaskets - Spec torque is 15.5 ft lbs I went to 18 but did not cut down on smoking
B. Intake manifold gaskets
C. Exhaust gaskets
D. Valve cover gaskets

After these repairs tractor smoking even more now, the block and heads appeared to be intact without a crack. I used a flexible 320 grit disc to clean the mating surfaces. There is a great deal of opinion out there regarding what and what not to use to clean the mating surfaces. I tried a razor blade but the gasket was so stuck I could not get it off with the razor blade without being to aggressive and scratching the head so I went with the 320 flexible disc which worked well and left minimal swirl.

At this point I could
1. Part it out
2. Take the heads off again, check if they are true, have them machined.
3. Get used heads off ebay (concerned that there could be an issue with fitment/damage etc).
 

·
Registered
Joined
·
73 Posts
How is your oil level? these things are notorious for float valves that don't seal. This would fill your crankcase with gasoline. The "sweet smell" may be gas, oil, and Lucas Oil Stabilizer. Just a thought.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #36
No noticeable loss in oil, hard to tell though since I'm not running it very long at the moment due to the clouds of smoke. You could be on to something with the sweet smell being gas and oil though, trouble is the smoke is very very white not blue as described. I did notice that the air filter smelled like gas when I checked it the other day. How would I check the float valve?
 

·
Premium Member
Joined
·
1,958 Posts
You torqued the intake manifold bolts right?

It is running on both cylinder right?
 

·
Registered
Joined
·
442 Posts
Now we know the real reason for the smoking (more so after you did this..... Your quote: "I was able to artificially get it up to speed by forcing the governor linkage further". Do you know what happens to the rpms of the engine when you advance the governor arm assembly on the shaft? You get about 4600 or more "red line" rpms from the engine and it blows the "guts" out of the engine.. All seals are blown, rings get broken...and there is where the oil gets into the combustion chamber...and the smoke never stops. You might also have a crack piston, bent push rods, and more damage than you realize.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #39
I only pushed the rpms to spec which is 3400, could I have still blown the engine? I'm ok with that if that is the case, I just need to know so I can move on if that is what needs done.
 

·
Registered
Joined
·
40 Posts
Well, that's a huge frustrating bummer, That leaves it to re-powering, parting or further diagnosing. If you want to dig a bit more, find your self a compression gauge and a leak down gauge, those will help with combustion chamber/ piston issues. One will tell you if there is cylinder pressure at what PSI the other will help point out where its going. What did the inside of the cylinders look like? Any cross hatching or smooth spots, you want cross hatching, you don't want flat spots.

At this point it may be worth changing the oil and going back to straight oil with no additives. Taking note of the color and sheen of what comes out, the dip stick wont tell you everything. Anything floating in the coolant?
 
21 - 40 of 70 Posts
Top