D1402 head replaced now oil leaks out exhaust

[jovol]

Hello,

I'm in the midst of putting a new head on a D1402 in an old trackhoe. Got the head and gasket kit as a set off ebay. Head seems to be of the same quality as all the aftermarket d1402 heads out there. Reinstall went fine except for a number of small fuel leaks that required new copper gaskets. Now that I have it running, there is a dripping oil leak out the exhaust. Does this indicate a bad head gasket or a bad head, or perhaps something else like a missed oil seal? (I'm not aware of any oil seals between the block and the head... just the head gasket between them correct?)

Thanks,
John

 

[wdlanning]

Hello,

I'm in the midst of putting a new head on a D1402 in an old trackhoe. Got the head and gasket kit as a set off ebay. Head seems to be of the same quality as all the aftermarket d1402 heads out there. Reinstall went fine except for a number of small fuel leaks that required new copper gaskets. Now that I have it running, there is a dripping oil leak out the exhaust. Does this indicate a bad head gasket or a bad head, or perhaps something else like a missed oil seal? (I'm not aware of any oil seals between the block and the head... just the head gasket between them correct?)

Thanks,
John

Check the parts list for your engine. I would bet that there is a O-ring on a oil outlet under the head

 

[JerryMT]

Hello,

I'm in the midst of putting a new head on a D1402 in an old trackhoe. Got the head and gasket kit as a set off ebay. Head seems to be of the same quality as all the aftermarket d1402 heads out there. Reinstall went fine except for a number of small fuel leaks that required new copper gaskets. Now that I have it running, there is a dripping oil leak out the exhaust. Does this indicate a bad head gasket or a bad head, or perhaps something else like a missed oil seal? (I'm not aware of any oil seals between the block and the head... just the head gasket between them correct?)

Thanks,
John

Are you sure it's oil and not "diesel slobbers"?

 

[wdlanning]

Check y

Check the parts list for your engine. I would bet that there is a O-ring on a oil outlet under the head

our coolant for oil

 

[jovol]

Closest thing I can see in the parts breakdown is item#200 in the parts diagram is an oring. But it looks like its under a pin/pipe. It also doesn't look that close to an exhaust valve.

It's definitely black engine oil, not diesel nor coolant.

 

[wdlanning]

Closest thing I can see in the parts breakdown is item#200 in the parts diagram is an oring. But it looks like its under a pin/pipe. It also doesn't look that close to an exhaust valve.

It's definitely black engine oil, not diesel nor coolant.

Good you found the. O-ring. Goes around small stand pipe over the head gasket. Just check and monitor oil in coolant.

 

[jovol]

guess you're right. service manual even says right there "Do not forget to refit the o-ring"

 

[jovol]

Alright, replaced the oil feed oring and it STILL leaks oil out the exhaust. Any advice on next step?

 

[PoTreeBoy]

Alright, replaced the oil feed oring and it STILL leaks oil out the exhaust. Any advice on next step?

Valve seal/guide?

 

[#40Fan]

Wow, that is crazy. Do you have a valve spring tool?

Tool

 

[whitetiger]

Alright, replaced the oil feed oring and it STILL leaks oil out the exhaust. Any advice on next step?

The o-ring around the oil feed tube could not leak oil from the exhaust ports. If it was leaking, it could only leak from the head gasket joint altho the head gasket itself would probably seal it anyway.

When you had the head off, was there any oily film on the pistons?

 

[jovol]

The new head came with new valves and springs pre installed. The handful of times I’ve pulled the head off I haven’t noticed any noticeable amounts of oil on the pistons. Maybe the valve seals are junk. I compression tested cylinder 3 and it was good, I’ll check 1 and 2 tomorrow. How would I go about making sure the valve seals are good? Is the hypothesis that oil is leaking from above the cylinder head into the exhaust port? If the seals are junk on the exhaust, decent chance they’re bad on the intake in which case I should check for oil in the intake manifold? Or I guess the flow of air might just suck that oil into the combustion chamber and it be burned. I’m not seeing any blue smoke with it running to indicate oil in the combustion chamber.

Could a faulty head gasket cause this? I don’t see how else oil could get in the exhaust with a noticeable flow other than leaking through an exhaust valve seal. But maybe I’m missing something.

thanks for the support, much appreciated

 

[whitetiger]

The new head came with new valves and springs pre installed. The handful of times I’ve pulled the head off I haven’t noticed any noticeable amounts of oil on the pistons. Maybe the valve seals are junk. I compression tested cylinder 3 and it was good, I’ll check 1 and 2 tomorrow. How would I go about making sure the valve seals are good? Is the hypothesis that oil is leaking from above the cylinder head into the exhaust port? If the seals are junk on the exhaust, decent chance they’re bad on the intake in which case I should check for oil in the intake manifold? Or I guess the flow of air might just suck that oil into the combustion chamber and it be burned. I’m not seeing any blue smoke with it running to indicate oil in the combustion chamber.

Could a faulty head gasket cause this? I don’t see how else oil could get in the exhaust with a noticeable flow other than leaking through an exhaust valve seal. But maybe I’m missing something.

thanks for the support, much appreciated

Have you had your injectors tested?

 

[jovol]

Have you had your injectors tested?

I haven’t. Good idea

 

[#40Fan]

Look into the exhaust ports. Is the oil coming down from the top of the port where the valve goes through the guide? Possibly around the guide?

 

[jovol]

dropped off my injectors today to get checked. will report back

 

[JerryMT]

Alright, replaced the oil feed oring and it STILL leaks oil out the exhaust. Any advice on next step?

How are you using this machine? Are you running long periods of time at idle and low power?

 

[RBsingl]

How are you using this machine? Are you running long periods of time at idle and low power?

That is a great question!

When I first installed my 40 KW diesel standby generator a few years ago, it "slobbered" a little oily residue out around my not fully tightened connection to the muffler. I suspect it had idled a bit after its initial load testing after assembly and before shipping to me and it was run at low power for a few hours of break-in after I got it. Once I loaded it down, that residue stopped and has never returned (I left the muffler connection a bit loose just to check it for the first 50 hours of operation).

I let it run a monthly test loaded and I make sure it is heavily loaded during that 25 minute run time which often means running both central AC systems along with space heaters and with two showers in simultaneous operation to keep both electric water heaters drawing current.

Rodger

 

[JerryMT]

That is a great question!

When I first installed my 40 KW diesel standby generator a few years ago, it "slobbered" a little oily residue out around my not fully tightened connection to the muffler. I suspect it had idled a bit after its initial load testing after assembly and before shipping to me and it was run at low power for a few hours of break-in after I got it. Once I loaded it down, that residue stopped and has never returned (I left the muffler connection a bit loose just to check it for the first 50 hours of operation).

I let it run a monthly test loaded and I make sure it is heavily loaded during that 25 minute run time which often means running both central AC systems along with space heaters and with two showers in simultaneous operation to keep both electric water heaters drawing current.

Rodger

 

[JerryMT]

Sure looks like diesel slobbers to me. dark black and runny. How many watts is your load? You have a 40KW machine. What % of rated load are you running.
I'm not familiar with the lube oil system on these Kubota's. Valve guide clearance is one possibility. IIRC you put a new head on it. Was it rebuilt? If so, the guides should have been replaced or at least knurled to maintain clearance. It's not like a gasser where the delta p across the guides is high at low rpms so it will suck oil with high clearance. What's your oil consumption under load? Does the coolant get to operating temperature when you run it for 25 minutes? I'll follow this this thread and reply if I get any more ideas.