Oil & Fuel Jinma 254 Won't Start After Oil Change

[MondelloRanch]

OK once again I need some help/opinions/advice. I have a Jinma 254 with the Laidong engine, that I bought last summer. So far I haven't had a bit of a problem with it. The last few weekends have been rainy up here, so I've been trapped in the barn. I thought it would be a perfect opportunity to do the 25 hour oil change, right?

After changing the oil, the engine will crank forward less than a full revolution and stop. When you let up on the key, you can hear it moving backwards a little bit. Poking around on the 'net, I think I managed to hydrolock it. Wish I'd done some research first and learned to pour the oil in slowly and carefully instead of not paying attention to the funnel backing up. I suppose it would also help if I had any previous diesel experience at all

So, how do I clear this? I've seen something about removing the injectors. Is there a simpler way? If not, I can see how to remove the high pressure fuel lines between the pump and the injectors, but what happens after that?

Thanks for any help.

 

[quicksandfarmer]

I would also look at the hydraulic quick-connects. If the hydraulics have come apart the flow is blocked in the system and the hydraulic pump will jam, keeping the engine from turning.

If it's hydrolocked: does your engine have compression release? Opening the compression release should solve the problem.

 

[MondelloRanch]

Thanks, I'll check the hydraulic lines also. As far as I know, the Laidongs don't have a compression release lever (unless it's in the engine compartment somewhere).

 

[cleat]

If you have glow plugs, you could remove those I suppose.

Cleat

 

[Diamondpilot]

I doubt you hydro locked it. Sounds like a hydraulic issue.

Check all fittings.

Chris

 

[MondelloRanch]

I sure hope it's something like a disconnected hydraulic fitting. I'll check all those tonight when I get home. That gets me to thinking though. I also topped up the hydraulic reservoir while I was waiting for the oil to drain. If I overfilled it, would this cause a similar problem? I thought I brought it up to the line on the dipstick, but it's so clean it was hard to tell exactly where it stopped.

 

[Diamondpilot]

I sure hope it's something like a disconnected hydraulic fitting. I'll check all those tonight when I get home. That gets me to thinking though. I also topped up the hydraulic reservoir while I was waiting for the oil to drain. If I overfilled it, would this cause a similar problem? I thought I brought it up to the line on the dipstick, but it's so clean it was hard to tell exactly where it stopped.

No, overfill will not cause issues other than make a mess when it comes out of the vent.

Most common cause is people monkey with the quick connects to the FEL and don't get them seated well. It will dead head the motor, blow out seals, and potentially crack the pump housing.

Chris

 

[Rich Waugh]

I'd guess that you you hydro-locked the engine by dumping the oil in the valve cover too quickly. These engines have a very small drain down hole from the valve train to the sump and if you have one valve open at the time you're dumping in the oil, it will find its way into that cylinder, locking it up. As noted, if you have a compression release use that while cranking it. With no comp release, you'll have to pull the glow plugs or injectors to give the oil somewhere to go. I'd use the glow plugs rather than the injectors if possible - I hate messing with injectors as they're such precise little things.

Definitely check the QD's before anything else, but if they're connected right then hydrolock is your problem. My 304 Jinma has a separate oil filler neck down on the left side of the block and I use that so I don't have this issue. Does your engine have anything like that?

 

[MondelloRanch]

No, the oil filler is in the middle of the valve cover, that's why I suspected hydro lock. And definitely good advice about removing the glow plugs, I wasn't looking forward to messing with the injector circuit. I just have to figure out where they are now, I don't remember seeing them (but of course I wasn't looking either).

 

[RonMar]

Your engine may have the compression release hardware on it, it just dosn't have the linkage connected to somewhere usefull like a handle. If you do you will have an assembly bolted to the back of the valve cover. It has a rod with a lever pointing off to the left/intake side of the engine. If you have this, push and hold the lever down and crank the engine. If not, release the hold downs on the injectors or pull the glowplugs.

I do not think it was the hydraulics, unless you have a real anemic starter and battery system. The reason I think this is gear rotor pumps don't typically build pressure right away, and you should be able to crank thru that low backpressure to start the engine. It is when the RPM builds after start that all **** usually breaks loose in the form of blown hoses, cracked pump housings or blown shaft seals dumping hydraulic oil into the oil sump.