Kubota M-59 Rebuild?

[americana36]

I have owned this 2008 M-59 for three years. Purchased with 600 hrs. It now has 900 hrs. It has always cold started easily but has a rough idle and belch's black smoke and gray smoke for about 30/45 seconds then it smooths out and runs fine. I'm not sure if it has the power it should because it has been like this since I purchased it but it does the job for me here on my rural property.
I rolled the dice and replaced the injectors last month thinking that one may be flooding a cylinder with fuel after shut down. No improvement....While the injectors were out I did a compression test (315/320 dry 350ish wet) and I tested and verified that all glow plugs and the glow plug system was functioning correctly. I also adjusted the valves but they were all close to within specification. Filters and maintenance have been performed religiously while I have owned it but someone told me that it sounded like the engine had been "dusted."
I'm considering an in-frame rebuild this winter, just curious of others experiences or opinions on attempting this endeavor. I think OEM parts would be best, but expensive, any opinions on aftermarket rebuild kits?
Thanks!
I

 

[eserv]

I have owned this 2008 M-59 for three years. Purchased with 600 hrs. It now has 900 hrs. It has always cold started easily but has a rough idle and belch's black smoke and gray smoke for about 30/45 seconds then it smooths out and runs fine. I'm not sure if it has the power it should because it has been like this since I purchased it but it does the job for me here on my rural property.
I rolled the dice and replaced the injectors last month thinking that one may be flooding a cylinder with fuel after shut down. No improvement....While the injectors were out I did a compression test (315/320 dry 350ish wet) and I tested and verified that all glow plugs and the glow plug system was functioning correctly. I also adjusted the valves but they were all close to within specification. Filters and maintenance have been performed religiously while I have owned it but someone told me that it sounded like the engine had been "dusted."
I'm considering an in-frame rebuild this winter, just curious of others experiences or opinions on attempting this endeavor. I think OEM parts would be best, but expensive, any opinions on aftermarket rebuild kits?
Thanks!
I

In my experience an in-frame rering job is rarely satisfactory. If your engine has been "dusted" it will need to have the cylinders repaired. The compression is definitely on the low side and likely causing the rough idle and smoke on cold start.

 

[lugbolt]

yeah your compression is real low I liked to see up around 500 psi on those.

With that said, you can get the head off in frame. Still a pain in the butt. Once the head is off, you can measure the cylinder bore diameters. If they are out of round or tapered you will have to pull the engine and bore/hone the cylinders & replace the pistons/rings. Putting stock stuff back together in tapered/worn cylinders, as said, rarely works. It is at best a temporary "fix". If you plan on keeping it do it right.

 

[americana36]

In my experience an in-frame rering job is rarely satisfactory. If your engine has been "dusted" it will need to have the cylinders repaired. The compression is definitely on the low side and likely causing the rough idle and smoke on cold start.

Thanks for your advice. I'm still shocked that such a low hour engine would have this problem.... I guess it didn't get the care that it deserved before I bought it.

 

[americana36]

yeah your compression is real low I liked to see up around 500 psi on those.

With that said, you can get the head off in frame. Still a pain in the butt. Once the head is off, you can measure the cylinder bore diameters. If they are out of round or tapered you will have to pull the engine and bore/hone the cylinders & replace the pistons/rings. Putting stock stuff back together in tapered/worn cylinders, as said, rarely works. It is at best a temporary "fix". If you plan on keeping it do it right.

I've been reading that this is a sleeved engine. I've rebuilt many gas engines but never a diesel. I want to avoid pulling the engine for a major overhaul and was hoping that I might be able to install new sleeves and pistons in-frame.
Thanks for the reply.

 

[eserv]

I've been reading that this is a sleeved engine. I've rebuilt many gas engines but never a diesel. I want to avoid pulling the engine for a major overhaul and was hoping that I might be able to install new sleeves and pistons in-frame.
Thanks for the reply.

It isn't a sleeved engine. Pistons are available .25mm over so you can bore it to that.