D1105 failure to start - need ideas

[Kubota_Mac]

Background - The engine is 20 years old but only has 1000 hours on it. Was having increased blow-by, but still started fine and had a decent amount of power. Checked compression, and was down to 300psi in two cylinders.

Pulled the head and pistons. Two of the pistons had broken rings and a small crack near one of the pre-ignition chambers on the head. Honed the cylinders to break the glaze. Installed all new rings, rod bearings, and two pistons. Installed new head/valves/seats and head gasket. Bled the air from the injectors and verified they are spraying fuel. Verified glow plugs work.

Problem? Cannot get the thing restarted. Checking compression via the glow plug holes, there is only around 150 psi on all three cylinders. If I add a tad of oil, it goes to 400psi, so the rings have not seated/sealed yet?

Have a new large-capacity battery to spin it as fast as possible, but it does not spin real fast (but it never has).

Not sure where to go from here.

 

[85Hokie]

So - the new rings/pistons and compression is cut in half?

So one old piston got new rings?

DID you mic any of this before the install ? Piston diameter in both directions and bore in both directions?

Adding oil to help compression on a diesel is not a good idea - that oil will ignite too!

 

[North Idaho Wolfman]

If you only have 150PSI, you didn't get something right on the rebuild.
It won't start unless the PSI is much higher from the get go.
Check the valves to make sure they are not too tight, but that's a huge long shot.
Rereading your 400 with oil brought it up to pressure, you have a bad ring job or bad pistons (worn ring lands) or cylinders are just too large.

 

[Russell King]

I believe there are head shims to use if the head (or block?) has been milled.

Did you use any additional shims along with the head gasket?

 

[JerryMT]

Background - The engine is 20 years old but only has 1000 hours on it. Was having increased blow-by, but still started fine and had a decent amount of power. Checked compression, and was down to 300psi in two cylinders.

Pulled the head and pistons. Two of the pistons had broken rings and a small crack near one of the pre-ignition chambers on the head. Honed the cylinders to break the glaze. Installed all new rings, rod bearings, and two pistons. Installed new head/valves/seats and head gasket. Bled the air from the injectors and verified they are spraying fuel. Verified glow plugs work.

Problem? Cannot get the thing restarted. Checking compression via the glow plug holes, there is only around 150 psi on all three cylinders. If I add a tad of oil, it goes to 400psi, so the rings have not seated/sealed yet?

Have a new large-capacity battery to spin it as fast as possible, but it does not spin real fast (but it never has).

Not sure where to go from here.

That compression number is too low. Either the valves are not set correctly or the valve timing is incorrect. Is it possible the head gasket was too thick?

 

[North Idaho Wolfman]

That compression number is too low. Either the valves are not set correctly or the valve timing is incorrect. Is it possible the head gasket was too thick?

Most likely bad ring job, bad pistons, or cylinder have excessive wear, as when he squirts oil in it it goes up to 400.

 

[NorthwoodsLife]

Not a pro, but I'd guess that your timing is off. Easiest fix. Valves open at the wrong time, no compression, no bang.

Or your cylinder hone / rings / pistons spec is way off. Not so easy fix. But should still run, maybe.

Did you hone the cylinders yourself?

 

[fried1765]

Not a pro, but I'd guess that your timing is off. Easiest fix. Valves open at the wrong time, no compression, no bang.

Or your cylinder hone / rings / pistons spec is way off. Not so easy fix. But should still run, maybe.

Did you hone the cylinders yourself?

Timing off does not explain low compression test results!

 

[Kubota_Mac]

So - the new rings/pistons and compression is cut in half?

So one old piston got new rings?

DID you mic any of this before the install ? Piston diameter in both directions and bore in both directions?

Adding oil to help compression on a diesel is not a good idea - that oil will ignite too!

Yes. the piston that did not have broken rings was reused, in the same cylinder. The new rings were standard size and installed in the correct grooves with the labels up and gaps spaced apart per the manual. I did not mic the cylinder walls because the initial compression, even with broken rings, was not that bad... the thinking was that new rings would improve the situation over the worn rings, once the rings are seated and sealed up. Some say to expect low compression prior to the engine running a bit to get rings sealed. Has anyone here measured compression prior to the first start following a ring job?

 

[Kubota_Mac]

Not a pro, but I'd guess that your timing is off. Easiest fix. Valves open at the wrong time, no compression, no bang.

Or your cylinder hone / rings / pistons spec is way off. Not so easy fix. But should still run, maybe.

Did you hone the cylinders yourself?

The cover where the timing is set via gears was not removed and this engine was running before the head was taken off, so I am pretty sure the timing has to be right. The valve lash has been checked and re-checked and should be spot on. The cylinder hone was very minimal... just enough to break the glaze. There were no groves or indents in the walls.

 

[Kubota_Mac]

That compression number is too low. Either the valves are not set correctly or the valve timing is incorrect. Is it possible the head gasket was too thick?

I did not mic the head gasket, but by feel it seemed to be the same weight and thickness as the original that came off without breaking. I did not use any sealer on the head gasket... just cleaned up the mating surfaces and torqued the head down to spec using the pattern specified in the tech manual.

 

[Kubota_Mac]

I believe there are head shims to use if the head (or block?) has been milled.

Did you use any additional shims along with the head gasket?

The head is brand new. The block was not milled. I checked it for flatness, and it seemed very flat. No additional shims (or sealants) were used with the head gasket.

 

[85Hokie]

Yes. the piston that did not have broken rings was reused, in the same cylinder. The new rings were standard size and installed in the correct grooves with the labels up and gaps spaced apart per the manual. I did not mic the cylinder walls because the initial compression, even with broken rings, was not that bad... the thinking was that new rings would improve the situation over the worn rings, once the rings are seated and sealed up. Some say to expect low compression prior to the engine running a bit to get rings sealed. Has anyone here measured compression prior to the first start following a ring job?

How long have you glowed the plugs? I would think that IF YOU get it started the heat will build and the rings will seat - I still do not understand the low PSI - if the valves were not correct the oil you placed in the cylinder would not have fixed a valve problem. SO in my opinion there has to be a sealant problem with the rings.

I would glow the hell out of that engine - see IF you can get it to fire before tearing it down again.

 

[Kubota_Mac]

How long have you glowed the plugs? I would think that IF YOU get it started the heat will build and the rings will seat - I still do not understand the low PSI - if the valves were not correct the oil you placed in the cylinder would not have fixed a valve problem. SO in my opinion there has to be a sealant problem with the rings.

I would glow the hell out of that engine - see IF you can get it to fire before tearing it down again.

Yes, I like your thinking. It's a bit of chicken or egg... I need it to run to get the rings to seat, but it won't run until I get compression which is because the rings are not seated. The other item working against me is that it has been cool here... 40-50 F. I just bought a propane heater that I can use to heat everything up to make the first start easier. This should thin the oil and let it crank a bit faster, and preheat the block so it is not sinking away as much of the heat needed for combustion. Once it is running, I expect things to get better.

 

[North Idaho Wolfman]

Are all the cylinders at the same compression?
I'm wondering if the head is wrong?
You replaced it, right?
And why did you replace it?
Was it an IDI or a DI head?

 

[85Hokie]

Are all the cylinders at the same compression?
I'm wondering if the head is wrong?
You replaced it, right?
And why did you replace it?
Was it an IDI or a DI head?

If the head was wrong - how did compression come up with a spoonful of oil in each cylinder? Thats the thing that has me stumped!

 

[North Idaho Wolfman]

If the head was wrong - how did compression come up with a spoonful of oil in each cylinder? Thats the thing that has me stumped!

If it's an IDI head on a DI engine it will do that because you've now taken up the volume that the IDI head to match the DI heads volume.

 

[Kubota_Mac]

If it's an IDI head on a DI engine it will do that because you've now taken up the volume that the IDI head to match the DI heads volume.

The description of the head is:

New Cylinder Head Assy With Valves For Kubota Engine D1105 D1105-E D1105BH Excavator KX41 KX61-2 1G065-03044

I cannot see any differences in the casting compared to the original head. My engine is stamped with D1105-E. Did Kubota make a version of the D1105 that is DI and not IDI?

My D1105-E is in a ZD-28 mower made only between 2002 and 2006.

 

[sitric]

Did they even use di with the D1105? I haven't seen any references to it if they did.

 

[Kubota_Mac]

Are all the cylinders at the same compression?
I'm wondering if the head is wrong?
You replaced it, right?
And why did you replace it?
Was it an IDI or a DI head?

The head was replaced because I observed a very small crack near the center port where
the fuel comes into the middle cylinder. I didn't want to have that fail and be an issue later, so I bit the bullet and bought the new head pre-populated with new everything. I think they are both IDI heads. The glow plugs go into a chamber that you cannot easily see from the cylinder side. If it was DI, would the glow plug be more exposed to the cylinder?