Oil & Fuel Jinma 254 Blowby Compression Testing

[Affordable]

At $ 1,700.00 plus in Parts, I think you should get the complete new crated engine and bolt it in at the $ 3 K, it will have a new water pump, fan, alternator,injection pump,ect.It will save you a lot of time plus misc. money that you will have to spend on other parts,plastigauge,torque wrench, ect. These crated engines are pretty well ready to go, you have to mount your hydraulic pump,put fluid in, modify your linkage a little,

Tommy
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[quicksandfarmer]

Have you done a compression test since you did all that work?

 

[quicksandfarmer]

The result...NO Improvement. Still hard starting, crazy loud knocking, lots of blowby (indicated by smoke coming out crankcase breather) and a lack of power.

The blowby is the stumper. Air in the fuel lines can cause knocking.

A few other notes:
- After a lot of cleaning I noticed what appears to be a very small crack in the block between cylinders 2 and 3.

Not an expert, but my thinking is on a sleeved engine this shouldn't be a problem of itself.

- Running temp on cylinder 1 appears to be ~100 F lower than #2 and #3 (running at ~200 F on #1 vs. ~300 F on #2 and #3) Checked with Infrared Thermo on exhaust manifold

Sounds like cylinder 1 isn't firing.

 

[Bob Rooks]

In my post #14 I indicated that the liners appeared to be glazed and scored - there is your source of blow-by and possibly knocking from piston slap and/or bad rod/main bearings, hard to tell from here. I thought you might have wanted to tackle that prospect first.
So now you're at a crossroad. But knowing now that the engine has had little to no maintenance performed on it, and possibly a stressed block casting (the crack), it is, imho, time to consider a complete engine with all new components - and a warranty.

 

[gromitbeast]

Thanks for the comments guys.

- I did not do another compression test after re-assembly quicksandfarmer...other than curiosity I can't see a reason to, did you have something in mind?
- Air in the fuel lines...this is the simple kind of thing that I'm worried I'm missing. Though I think I'm ok because I have been following the recommended procedure for bleeding air out of the fuel lines (Bleeding fuel system | CHINESE TRACTOR OWNERS CLUB FORUM and Using Hand Pump & Purgeing Air From Fuel Lines | CHINESE TRACTOR OWNERS CLUB FORUM)
- Regarding the sleeves and crack that's kind of what I was thinking...if it is actually a crack I would be surprised if it would be the cause of all the problems I'm seeing...but not beyond the realm of possibility
- I do think cylinder 1 is firing, though maybe not efficiently. I know this because after re-assembling I fired it up to test and the high pressure fuel line to #1 was a bit too loose and leaking fuel, I tightened it up and could hear a change in performance.
- Bob, regarding glazing I think you may be right and I think I should have paid a bit more attention to that fact. I can't really do anything about glazing on the sleeves unless I split and remove right?

Based on the advice of Tommy/Quicksand/Bob...I'm kind of leaning towards a new engine. $3k is a pretty large investment though so I'd really like to exhaust any other potential troubleshooting that doesn't involve splitting the tractor...

One thing I haven't checked is the timing on the pump...can you guys think of a reason I might want to do this? Also, is there a good way to be sure all the injectors are delivering well?

Thanks,

Nick

 

[Bob Rooks]

My bad. I had assumed that you had checked the timing, and that it was ok since you didn't mention it. Arghh.
Bad timing can be a cause of hard starting. Low compression can also be a cause of a bad injector symptom - switch the injectors around to see if the problem follows the suspect injector. Injector performance can be observed and calibrated when set up on a test bench but a simple pop test can be performed in the field if you have the right equipment. Best to just take them to a diesel shop to be tested. Shouldn't cost much. It's also cheaper to replace with new than to try to rebuild (unless you have a $35,000 test bench. Lol).

 

[quicksandfarmer]

Thanks for the comments guys.

- I did not do another compression test after re-assembly quicksandfarmer...other than curiosity I can't see a reason to, did you have something in mind?
- Air in the fuel lines...this is the simple kind of thing that I'm worried I'm missing.

Some of the most vexing problems can happen where there are multiple things wrong. We've already seen that in this case, where clearly there were issues with the cylinder head, but things beyond that.

In terms of the blow-by, in the words of Bernie Madoff, "there is no innocent explanation." There had been some possibility that leakage in the cylinder head was causing it, but with the work you've done I think you can say conclusively that either one or more pistons, or the engine block itself, is bypassing. So now you have to make two decisions:
1. Whether to repair the tractor or get rid of it.
2. If you decide to repair it, whether to repair the engine or replace it.

Ultimately, it's going to be your decision. Here's the thought process I would go through: You can buy a brand new 254 for about $8,000. I'm going to take a wild guess and say that in good used condition one is worth half of that, or $4,000. When all is said and done it could cost $4K in parts and labor to get your tractor running, so from an economic perspective it has little value beyond what the local scrap yard is paying per ton. I may be way off, you can test that by posting an add on Craigslist to gauge the interest, it's anonymous and there's no obligation to sell if you list something.

There are a couple of reasons to go the repair route. You have the tractor already. If you are able to do the repair more cheaply you are essentially paying yourself. If you have to pay someone else, or if you have high-paying work that you're turning away to tinker with your tractor, it's probably not worth it, but if the alternative is watching a rerun of "Star Search" it is. We're all here because we like tinkering with our tractors, so you probably won't find much support for cutting and running from us.

In terms of the repair/replace decision for the engine, that's really determined by how bad things are inside the engine. It's entirely possible that there is just one cylinder blowing by, and a new set of rings and a sleeve fixes everything for less than $100. At the other end of the spectrum, you could open the engine up and find it's a basket case, the pistons, bearings, crankshaft and camshaft are all damaged, the block is ruined, a new engine is your only hope. (Based on your description of the head the second case sounds more likely but you never know.) But here's the thing: either way, you start off by doing the same thing, splitting the tractor, and that's the real work. Once the tractor is split it might take you another hour to get the bottom off and see if you've got anything worth saving.

If I decided to go the tractor repair route, what I would do is split the tractor as if I were going down the engine repair route, and take the engine apart until I had determined exactly what needed to be repaired. Then I would price all the parts needed before deciding whether to repair or replace the engine. If you replace the engine, there is also the mitigating factor that you will have some usable spare parts from the old one.

 

[sd455dan]

Thanks for the comments guys.

- I did not do another compression test after re-assembly quicksandfarmer...other than curiosity I can't see a reason to, did you have something in mind?
- Air in the fuel lines...this is the simple kind of thing that I'm worried I'm missing. Though I think I'm ok because I have been following the recommended procedure for bleeding air out of the fuel lines (Bleeding fuel system | CHINESE TRACTOR OWNERS CLUB FORUM and Using Hand Pump & Purgeing Air From Fuel Lines | CHINESE TRACTOR OWNERS CLUB FORUM)
- Regarding the sleeves and crack that's kind of what I was thinking...if it is actually a crack I would be surprised if it would be the cause of all the problems I'm seeing...but not beyond the realm of possibility
- I do think cylinder 1 is firing, though maybe not efficiently. I know this because after re-assembling I fired it up to test and the high pressure fuel line to #1 was a bit too loose and leaking fuel, I tightened it up and could hear a change in performance.
- Bob, regarding glazing I think you may be right and I think I should have paid a bit more attention to that fact. I can't really do anything about glazing on the sleeves unless I split and remove right?

Based on the advice of Tommy/Quicksand/Bob...I'm kind of leaning towards a new engine. $3k is a pretty large investment though so I'd really like to exhaust any other potential troubleshooting that doesn't involve splitting the tractor...

One thing I haven't checked is the timing on the pump...can you guys think of a reason I might want to do this? Also, is there a good way to be sure all the injectors are delivering well?

Thanks,

Nick

Sorry to hear the head work didn't take care of the problems. The blow by isn't a good thing but there are plenty of older diesels working every day with blow by, and your compression is enough to run

The thing that is a big deal for me at least- is the Knock, if its not an injector, or pump thing ( have you run the engine and cracked each of the lines one at a time ... another low buck check is to remove the injectors and turn the injector lines away from the engine re-connect them and bleed, lock the compression release in the open position then roll the engine over and compare the spray patterns.

They should be very similar with no dribbling. If the knock is related to the fuel injection, killing a cylinder one at a time should get rid of it unless the pump itself is out of time or multiple injectors are bad.

Now if the knock is obviously just one cylinder and not related to fuel injection , my guess would be a spun rod bearing and or wiped crankshaft rod journal. and from your description of (crazy loud) makes me think of the only way that I have seen an engine Knock that loud (Minus a bad injector) Is the piston is allowed to strike the head due to the extra clearance at the rod bearing. The knock will get even louder with an increase in rpms. I looked at the pictures again and don't see where the piston has contacted the head so it's not clear. What kind of oil pressure #s have you been seeing?

If the injection system is not the cause of the knock, I recommend splitting the tractor pulling the pistons and digging deeper especially since the blowby is still present. it will cost you time and work but not a lot of money to see whether a new engine is in order and solve some un answered questions... my :2cents:

 

[gromitbeast]

Quicksand/SD/Bob,

Thank you guys for the additional feedback. Very helpful. I especially like the thought process quicksand. I tried to sell it on craigslist over the past couple of weeks giving the details of what I knew/think is wrong with it and nobody bit so, I think I'll do exactly as you all suggest:
1. Have one more closer look at injectors and fuel timing.
2. If nothing is wrong there then split the tractor and see what there is to be seen.
I'll keep you all updated and try to take lots of pictures as I move along.

Thanks,

Nick

 

[reelnative]

Hi im kinda rowing your same boat down the same river and am at the head in the machine shop phaze, I have been checking around just incase I have to do the worst option and I found a place circle g out of mississippi that sells a y385 yangdong short block for 1500.00 and they also sell the crate for around 3k but 1500.00 is much easyer to take then 3k, I just thought I would drop that info on you incase you need to go that way here is there web site and good luck with it Jinma Tractor Parts, Farm Pro Tractor Parts, Farmpro, Nortrack, Agracat

 

[gromitbeast]

Hello All,

I thought you all might enjoy an update and some pictures in this saga. I began to split the tractor. Here is the process I've made so far:

I used Benye Tractor with Yangdong Diesel Engine | CHINESE TRACTOR OWNERS CLUB FORUM as a very nice guide.
1. Drain radiation fluid. Remove radiator
2. Disconnect headlights
3. Remove battery
4. Remove bucket from loader
5. Disconnect gauges and switches from body
6. Remove steering wheel (just the wheel)
7. Remove body
8. Drain diesel
9. Remove Diesel Tank
10. Remove arms of loader (used engine hoist)
11. Remove Right Side Arm Mount (first front cross member, then J-slotted piece, then stering mount) it came off easy. This exposes some of the hidden bellhousing bolts needed to split the tractors.
12. Remove Left arm mount (first j-slotted piece, then steering hydraulic piston) came off a bit harder. This exposes some of the hidden bellhousing bolts needed to split the tractors.
13. Removed 4WD front wheels drive shaft. First remove weldment clamps, collapse weldment. Remove the rear side first by pulling back on the coupler/spring then the front just comes right out. Mine had 6 ball bearings on the front and 5 on the back. Either I lost 1 or was it was missing a ball bearing to begin with. I’ll want to order some new dust boots when I am ready to re-assemble. This came off easy.
14. Remove electrical connections from front side of tractor and label all connections. (Alternator, starter, what I think is the voltage regulator, glow plug connections, temp sensor, oil sensor)
15. Remove low pressure hydraulic connection
16. Remove fill linkage, fuel linkage and de-compression linkage
17. Chock all wheels, jack up both front and back just a little bit, insert backup/safety jacks stands, hang engine from engine hoise
18. Unbolt bell housing. I noticed I had one missing bolt and the two bottom bolts were studs with double nuts. The bolts on the bell housing all came out with what looks like some thread sealant on them. I'm currently trying to shake the front and back halves apart. It's coming slowly but had to shut down at this point.

I'm labeling things as much as I remember to...and hopefully that will help during re-assembly. Where possible I'm replacing screws, bolts, nuts, washers, etc so that I don't have to scratch my head as to where they go on re-assembly.

So far so good and not too bad...going easier then I thought it would but I'm not done yet!

Reelnative,
I hope the head rebuild fixes your problem! Thanks for the link to the circleG site.

Here are some pictures:
https://plus.google.com/u/0/photos/100300971617064582658/albums/5906811590923544433

 

[jimogeek]

Wow!

Thanks for posting this detailed info, I really hope I don't have to go through it someday but if it happens I'll sure be following your post and directions you've laid out!

 

[jimogeek]

Wow!

Thanks for posting this detailed info, I really hope I don't have to go through it someday but if it happens I'll sure be following your post and directions you've laid out!

 

[reelnative]

hahaha i wish the head was it, you know it can never be that easy, I ended up having to get 3 new pistons and rings one sleeve,head gasket new rod bearings, and rod bolts and a new goose neck and water inlet, and the head shaved down, all on an eng with 69hrs, i just got her back together tonight and will finnish it up tomorrow and fire her off, good luck with yours