Jinma 354 white smoke no power won't rev past 800rpm

[mrmikey]

Be sure to support the engine from flopping one way or the other once you split it, couple pieces of 2 x 4 on the front axle will do it...........Mike

 

[sd455dan]

wow just read through this thread... Ouch


Sounds like you lost the oil pump and that lead to seizing and breaking the cam- and (possibly) blowing a head gasket -and likely bending some valves .

I would also be concerned the main bearings and rod bearings may be scored now to -and unfortunately it is possible the crankshaft itself is damaged.
Does your chinese tractors engine have either a removable side inspection cover or a removable plate on the bottom of the oil pan.

If so pulling a rod bearing cap and crankshaft bearing cap may help hone in on how much damage has been done. A real quick way of detecting major bearing damage would be to drain the oil into a clean container and then inspect the oil out in the sun, If there is significant wear, the oil will be full of shiny babbit material.

ps -it is possible to have (white) smoke from a diesel engine and be mostly unburned diesel- the smell will give it away though
sickly sweet is antifreeze, strong intense half burned fuel smell will be diesel.

Hope you can get the problems worked out and repaired without a big expense,

One good thing on these chinese tractors is the price of most replacement parts are nowhere near as expensive as some of the big name brands.

I take it your oil pump does not run off of the front crank gear??,
some chinese tractor engines oil pumps are driven off front crank gear on a parallel axis to the crankshaft itself. meaning the pump can be replaced without any splitting of the tractor assuming no other damage.

 

[Tim Berframe]

I have ordered parts and will go do my day job for a week while they ship across the country. I am collecting the tools required for a major repair.

I am going to pull the motor and do a complete tear down - top and bottom. It makes no sense to go so deep to change a cam and not check everything else - its not that much extra work. Peace of mind to know what the main bearings and rod bearings look like and to know that they are torqued on right. Plus, I need to get the back half of the broken cam out and change its bearings - easier with the crank out.

The oil is clean with no noticeable flecks so I'm hoping there is no bearing/journal damage.

I am going to pull the valves tomorrow. I do not expect any trouble there (this is a full clearance engine) but it wouldn't surprise me if they had never been ground right from factory.

I'm told that several others have had same problem due to an improper cam bearing installed that seizes and snaps the cam. I'm figuring that would have to be the back one (engine ran pretty smooth on those front two cylinders). If so, the pump should be OK. (pump runs off cam gear located on back half of cam shaft).

When this engine was available, I believe it cost about $6000 US. Parts from online direct retailer in China are really cheap but they do not ship to Canada. I'll go cheap as possible but not compromise while it is tore this far apart.

 

[mrmikey]

I'm told that several others have had same problem due to an improper cam bearing installed.....

The one I had bought new started acting up at 98 hours so I figured it was time for a valve adjustment. Took the valve cover off and there was nothing but metal dust over the valve train, no oil anywhere. Ended up the cam bearing on the aft end of the engine is used to meter oil to the top end was installed 180 deg out, no oil at all to the top end. Rocker arm bushings were shot and the rocker shaft was sketchy so I ended up getting a new assembly from Tommy at Affordable as well as a new cam bearing.
Wasn't too bad of a deal splitting it, hardest part was getting the oil pump off so I could pull the camshaft. Looking with one eye thru a small hole turning two 6mm bolts one flat at a time and flipping the wrench between each turn to remove the pump was not fun. I ended up replacing the bolts with socket head cap screws and it made a miserable job tolerable......Mike

 

[quicksandfarmer]

I have ordered parts and will go do my day job for a week while they ship across the country. I am collecting the tools required for a major repair.

I am going to pull the motor and do a complete tear down - top and bottom. It makes no sense to go so deep to change a cam and not check everything else - its not that much extra work. Peace of mind to know what the main bearings and rod bearings look like and to know that they are torqued on right. Plus, I need to get the back half of the broken cam out and change its bearings - easier with the crank out.

The oil is clean with no noticeable flecks so I'm hoping there is no bearing/journal damage.

I am going to pull the valves tomorrow. I do not expect any trouble there (this is a full clearance engine) but it wouldn't surprise me if they had never been ground right from factory.

I'm told that several others have had same problem due to an improper cam bearing installed that seizes and snaps the cam. I'm figuring that would have to be the back one (engine ran pretty smooth on those front two cylinders). If so, the pump should be OK. (pump runs off cam gear located on back half of cam shaft).

When this engine was available, I believe it cost about $6000 US. Parts from online direct retailer in China are really cheap but they do not ship to Canada. I'll go cheap as possible but not compromise while it is tore this far apart.

Tim, I like your attitude and approach. The working theory of a camshaft bearing failure makes sense to me. If it's that plus a head gasket I think you'll find it pretty straightforward. These are tough and capable engines and I've always found mine easy to work on.

Plus I like a good mystery so keep us posted as it unfolds!

 

[Tim Berframe]

Mine doesn't have the inspection port in the sump to do keyhole surgery through. 4 bolts behind the flywheel go into the sump so I have to split and remove clutch and flywheel

Mrmikey, did you pull the aft cam bearing to the rear or did it have to come out the front? If out front, do the others have to be removed first?

I'm getting some oil to the top end

It's a good thing that my educational opportunity serves some positive good for some. Ha ha. After this, it's someone else's turn again

 

[mrmikey]

Mrmikey, did you pull the aft cam bearing to the rear or did it have to come out the front? If out front, do the others have to be removed first?

Once I diassembled the oil pump so I could get the camshaft out I tapped it out forward thru the block I think, it's been awhile ago so it fell out the bottom, I only replaced the one that was in wrong. Watch when you remove the camshaft, the tappetts are solid and will drop down once you start pulling the camshaft and fetch up against the lobes. No big deal, you can just reach up thru the bottom of the block and push them up. The oil held a majority of them in place for a bit till I go it out. You can see one of the slotted holes in this pic, there's two. One is the supply from the oil supply galley, the other that you can't see is the supply to the top end. The rear cam boss has a narrow slotted groove about 60 degrees or so around the periphery of it that only aligns both holes for a portion of the rotation, that's what meters the oil to the top end.


Damage, you can see the worn sleeves in the rockers, could have been worse I guess.


When you put them back is a bit different, I used thick axle grease to hold them in place while I put the camshaft in. Try and reuse them in the same place

Don't forget a new welch plug for the end of the camshaft bore. I did and had to fill the hole I had drilled for pulling with a sheet metal screw with weld to reuse the old one..

Once you get the head off and if have to turn the engine over for any reason with the pistons still connected watch the sleeves don't move. I had to use some short pieces of 2 x 3 and the head bolts to put over the top of each cylinder to make sure they didn't move up.


Mark the gear train at the front to make sure you get everything aligned. I think that was a gasket I forgot to order and had to make also.


I had a bunch of pics on Photobucket when I did mine but we all know where they went. I guess they're still there, I attached a few...............Mike

 

[Tim Berframe]

Mike,

Thanks for the pics. How did you pull the old bearing and push in the new one?

I had to replace the timing cover case a couple years ago so I have had all of those gears off before. Timing is easy on this engine. Gears only go on one way and the marks are clear. Fuel advance is all that can go wrong - I put it back the way I found it and it was fine.

 

[mrmikey]

How did you pull the old bearing and push in the new one?

I carefully tapped the old one out using a screwdriver, wasn't tight at all. The new one I used a block of wood to get it started and used that as far as I could, once it was flush with the top of the counter bore (where the welch plug sits) I used the old bearing since I didn't care if that got screwed up. It went in the bore slightly but not enough to make it hard getting it out with a bit of wiggling. When you do put the new one in, make sure you get the two passages lined up and watch you don't drive it in too far..........Mike

 

[sd455dan]

I have ordered parts and will go do my day job for a week while they ship across the country. I am collecting the tools required for a major repair.

I am going to pull the motor and do a complete tear down - top and bottom. It makes no sense to go so deep to change a cam and not check everything else - its not that much extra work. Peace of mind to know what the main bearings and rod bearings look like and to know that they are torqued on right. Plus, I need to get the back half of the broken cam out and change its bearings - easier with the crank out.

The oil is clean with no noticeable flecks so I'm hoping there is no bearing/journal damage.

I am going to pull the valves tomorrow. I do not expect any trouble there (this is a full clearance engine) but it wouldn't surprise me if they had never been ground right from factory.

I'm told that several others have had same problem due to an improper cam bearing installed that seizes and snaps the cam. I'm figuring that would have to be the back one (engine ran pretty smooth on those front two cylinders). If so, the pump should be OK. (pump runs off cam gear located on back half of cam shaft).

When this engine was available, I believe it cost about $6000 US. Parts from online direct retailer in China are really cheap but they do not ship to Canada. I'll go cheap as possible but not compromise while it is tore this far apart.

That's a great plan,:thumbsup:
I knew there were differences in the design of some of these chinese diesel tractor engines , but that is a big one concerning driving the oil pump - totally different in design from my Shanghai.

Also good that yours is not an (interference) engine, pretty sure mine is,
I thought all diesel engines were of interference type due to the compression ratios involved?? most diesels have flat heads and only a small depression(chamber) in the piston crown,- not sure how the valves would not contact the piston unless it broke the cam at the cams TDC position for that cylinder? I guess I need to brush up on this part.

Looks like mmikey has been through this before with the same basic engine. And has insights on getting yours up and running again, Sure seems like some mis-indexed ( 180 degree's out ) bearing was the cause - no oil flowing through the oil passsage

I agree with pulling the engine and checking/ replacing any needed parts at this point. And can only help that mmikey is familiar with the same engine/ problem

Hope there are no more surprises to be found- and the repair goes well .