Compression issue

Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
Hi. I have an L2850 which starts with no problems but knocks loudly. After about 20 mins of running it starts to squeel as if a piston is running dry. It also produces a lot of white smoke. I changed the injector on piston 1(front) but still smoking. It also still knocks. When I loosen injector pipe fuel sprays out but white smoke from exhaust disappears. There is no change in engine sound when I do this but if I loosen the other 3 injector pipes ( independently) the engine definitely looses power. My conclusion is that there is no compression on cylinder 1 and suspect liner or piston damage or piston ring stuck. Can anyone advise if it is likely to be anything else. I don't want to strip engine unnecessarily. Also would it be possible to blank off injector 1 without damage to injector pump. I suspect fuel is diluting lubrication in cylinder leading to sqeeling. Fuel is also definitely getting into the sump and have to change oil and filter often. Tractor is doing what I need of it but I need to let it rest after 20 mins. If I stop fuel diluting oil I think it will continue to work as a 3 cylinder. Any opinions would be very welcome. Cheers Neil
 
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fried1765

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Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
Nov 14, 2019
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Hi. I have an L2850 which starts with no problems but knocks loudly. After about 20 mins of running it starts to squeel as if a piston is running dry. It also produces a lot of white smoke. I changed the injector on piston 1(front) but still smoking. It also still knocks. When I loosen injector pipe fuel sprays out but white smoke from exhaust disappears. There is no change in engine sound when I do this but if I loosen the other 3 injector pipes ( independently) the engine definitely looses power. My conclusion is that there is no compression on cylinder 1 and suspect liner or piston damage or piston ring stuck. Can anyone advise if it is likely to be anything else. I don't want to strip engine unnecessarily. Also would it be possible to blank off injector 1 without damage to injector pump. I suspect fuel is diluting lubrication in cylinder leading to sqeeling. Fuel is also definitely getting into the sump and have to change oil and filter often. Tractor is doing what I need of it but I need to let it rest after 20 mins. If I stop fuel diluting oil I think it will continue to work as a 3 cylinder. Any opinions would be very welcome. Cheers Neil
Have you tried doing a compression check,...... on all cylinders?
 
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85Hokie

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Hi. I have an L2850 which starts with no problems but knocks loudly. After about 20 mins of running it starts to squeel as if a piston is running dry. It also produces a lot of white smoke. I changed the injector on piston 1(front) but still smoking. It also still knocks. When I loosen injector pipe fuel sprays out but white smoke from exhaust disappears. There is no change in engine sound when I do this but if I loosen the other 3 injector pipes ( independently) the engine definitely looses power. My conclusion is that there is no compression on cylinder 1 and suspect liner or piston damage or piston ring stuck. Can anyone advise if it is likely to be anything else. I don't want to strip engine unnecessarily. Also would it be possible to blank off injector 1 without damage to injector pump. I suspect fuel is diluting lubrication in cylinder leading to sqeeling. Fuel is also definitely getting into the sump and have to change oil and filter often. Tractor is doing what I need of it but I need to let it rest after 20 mins. If I stop fuel diluting oil I think it will continue to work as a 3 cylinder. Any opinions would be very welcome. Cheers Neil

Neil,

I am not trying to be offensive but - IF this machine is knocking - shut it OFF and have it broken down soon! Running that machine in this format will only make fixing it more expensive when the time comes.

You have a ring that has broken, a piston that is slapping the cylinder wall (sleeve perhaps) and diesel is bypassing into the engine oil.

Running on 3 cylinders STILL pushes that 4th up and down - and when the rod breaks and pokes a hole in the side of the block, you will have wanted to have fixed that muuuuch earlier!
 
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Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
Have you tried doing a compression check,...... on all cylinders?
No. I don't have equipment for that. When I slacken injector pipe on the 3 others engine loses power. Slacken first one nothing happens apart from smoke lessens. Tractor starts first turn even after sitting for days/weeks
 

Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
Neil,

I am not trying to be offensive but - IF this machine is knocking - shut it OFF and have it broken down soon! Running that machine in this format will only make fixing it more expensive when the time comes.

You have a ring that has broken, a piston that is slapping the cylinder wall (sleeve perhaps) and diesel is bypassing into the engine oil.

Running on 3 cylinders STILL pushes that 4th up and down - and when the rod breaks and pokes a hole in the side of the block, you will have wanted to have fixed that muuuuch earlier!
Thanks. What you say sounds like good advice. At first I'd hoped the injector was causing knocking but new injector hasn't helped. Only discovered other symptoms whilst changing injector.
 

fried1765

Well-known member

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Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
Nov 14, 2019
7,843
5,066
113
Eastham, Ma
No. I don't have equipment for that. When I slacken injector pipe on the 3 others engine loses power. Slacken first one nothing happens apart from smoke lessens. Tractor starts first turn even after sitting for days/weeks
I do think that you need to beg, borrow, buy, or steal, a compression tester, to understand what is going on inside that cylinder.
 

Oleracer

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B2150 Kubota LA 350 750 Woods S250 Bobcat 300x deere
Jul 18, 2024
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Sounds like a spun rod bearing and piston top hit head because of clearance in rod.Whatever it is good advise to shut it off and start the deep dive into motor. Pull the oil filter off and cut it open carefully not useing anything that makes metal chips ( tin snips or filter cutter). Look at paper element. Either way you have an expensive engine job in your future i am afraid.
 

lugbolt

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ZG127S-54
Oct 15, 2015
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agree with oleracer

squealing sound is indicative of a connecting rod bearing that's spun. Possibly stacked. Stacked, meaning it's likely that the upper bearing has been beat up and "intermittently locked" itself to the crankshaft, then came loose. Since the clearance became excessive, the possibility exists that the two bearings are stacked on top of each other.

take the oil filter off and cut it open. If there's metal in it, you're gonna have to rebuild the engine.
 

lynnmor

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B2601-1
May 3, 2021
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Red Lion

woodman55

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May 15, 2022
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canada
Another option is one of those cheap bore scopes. But, regardless of what you find, it still needs the head and pan removed.
 
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Neil Gigha

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Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
agree with oleracer

squealing sound is indicative of a connecting rod bearing that's spun. Possibly stacked. Stacked, meaning it's likely that the upper bearing has been beat up and "intermittently locked" itself to the crankshaft, then came loose. Since the clearance became excessive, the possibility exists that the two bearings are stacked on top of each other.

take the oil filter off and cut it open. If there's metal in it, you're gonna have to rebuild the engine.
Thanks for advice everyone. I've decided to change piston and all gaskets. Unfortunately I've been changing filter regularly. The problem started because filter totally clogged up because I suspect it had been sitting for a while before I purchased it and oil pressure light was covered by a cow tag and didn't notice. The sqeeling I mentioned isn't constant but sounds more like piston than a bearing or similar. I'm hoping that it's a piston problem but I'll only find out by stripping it down a task I've never done before hence the reluctance to go down that route. Thanks again
 
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Oleracer

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B2150 Kubota LA 350 750 Woods S250 Bobcat 300x deere
Jul 18, 2024
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CT
Thanks for advice everyone. I've decided to change piston and all gaskets. Unfortunately I've been changing filter regularly. The problem started because filter totally clogged up because I suspect it had been sitting for a while before I purchased it and oil pressure light was covered by a cow tag and didn't notice. The sqeeling I mentioned isn't constant but sounds more like piston than a bearing or similar. I'm hoping that it's a piston problem but I'll only find out by stripping it down a task I've never done before hence the reluctance to go down that route. Thanks again
Well you’ll be the first to know! Pull the pan … drop the rod cap… you got it right there. If something is broken the complete motor needs to come out. Otherwise it will be nothing but a patch job.
Good Luck.. let us know what you find..
 

Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
Well you’ll be the first to know! Pull the pan … drop the rod cap… you got it right there. If something is broken the complete motor needs to come out. Otherwise it will be nothing but a patch job.
Good Luck.. let us know what you find..
Thanks. Iv now got it stripped down to just head bolts but can't get sump off. 4wd shaft in way. Come in to see what I need to do.(here and YouTube). Any advice other than take whole engine out would be much appreciated.
 

Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
Well you’ll be the first to know! Pull the pan … drop the rod cap… you got it right there. If something is broken the complete motor needs to come out. Otherwise it will be nothing but a patch job.
Good Luck.. let us know what you find..
Hi. Looks like you and lugbolt were spot on. Next step to get piston out and replace what's needed. Cheers Neil
 

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DustyRusty

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Nov 8, 2015
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Next step would be a total examination of the crank and cam. Looks like a total tear down to me. Might as well do a complete rebuild as long as you are already in there. Short cut engine rebuilds usually only last long enough to sell to some unsuspecting buyer and he inherits the future problems.
 
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Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
Next step would be a total examination of the crank and cam. Looks like a total tear down to me. Might as well do a complete rebuild as long as you are already in there. Short cut engine rebuilds usually only last long enough to sell to some unsuspecting buyer and he inherits the future problems.
Iv thought about that but I cannot justify any more money or time on it. The other 3 cylinders are working fine so I'm loathed to touch them although I will thoroughly check camshaft and conrods before reassembly. Iv no plans to sell so if I make wrong decision its on me and my conscious will be clear lol.
 

Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
agree with oleracer

squealing sound is indicative of a connecting rod bearing that's spun. Possibly stacked. Stacked, meaning it's likely that the upper bearing has been beat up and "intermittently locked" itself to the crankshaft, then came loose. Since the clearance became excessive, the possibility exists that the two bearings are stacked on top of each other.

take the oil filter off and cut it open. If there's metal in it, you're gonna have to rebuild the engine.
What would cause bearings to slip and stack?
 

Oleracer

Active member

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B2150 Kubota LA 350 750 Woods S250 Bobcat 300x deere
Jul 18, 2024
191
229
43
CT
Iv thought about that but I cannot justify any more money or time on it. The other 3 cylinders are working fine so I'm loathed to touch them although I will thoroughly check camshaft and conrods before reassembly. Iv no plans to sell so if I make wrong decision its on me and my conscious will be clear lol.
Only problem with that? They is a reason it let go. The motor will be full of shrapnel and just kick another rod or main. Oil pump possible…. Its no fun if you get it together and pop it lets go a day.. week or month later. You’ll better know when pan comes off. Maybe you’ll get 🍀
 

Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
Only problem with that? They is a reason it let go. The motor will be full of shrapnel and just kick another rod or main. Oil pump possible…. Its no fun if you get it together and pop it lets go a day.. week or month later. You’ll better know when pan comes off. Maybe you’ll get 🍀
Hi. Pan(sump) is off. 1 side ìs clean but other was full of sludge no sign of any metal. Going to undo conrod tomorrow and get piston out. Problem only seems to be cylinder 1 and others firing with engine starting first turn without heat. Of course if crankshaft damaged then I won't have any option but I'm hopeful it will be OK.
 
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Neil Gigha

New member

Equipment
L2850. M5112
Aug 11, 2024
12
4
3
58
Uk
Well you’ll be the first to know! Pull the pan … drop the rod cap… you got it right there. If something is broken the complete motor needs to come out. Otherwise it will be nothing but a patch job.
Good Luck.. let us know what you find..
Hi. Iv got another question. Iv stripped down head and taken piston out. 1 broken piston ring so replacing all 3. No bearing left so bought 0.04 bearings as cam journal was a bit scored and have been rubbing it down in situ. Conrod totally worn so have ordered a new one. My question is in new head gasket kit there are 3 copper washers and I cannot work out where they go. Are they surplus on my v1702 engine but used on an engine which uses this kit. Another thought was are the for the 3 pillars on the rocker which are not "fixed". Or is there 1 missing. There were no copper washers when i stripped it down. Any help with this conundrum would be much appreciated. Cheers Neil