Cat 951c engine, oil in exhaust manifold

[Vetech63]

That 2nd piston pic ....yeah, my money is on that one.

 

[Dave Neubert]

2nd piston looks like it is hitting the top of the head check rod and wrist pin also looks like it has a lot of burnt oil built up on it

 

[Vetech63]

2nd piston looks like it is hitting the top of the head check rod and wrist pin also looks like it has a lot of burnt oil built up on it

Or better yet that clean edge around that piston is caused by the unburned fuel leaving that cylinder with the compression. It needs to come out…….I’ll bet it looks like that piston pic Nige posted earlier.

 

[tctractors]

This engine looks well stuffed, the valve guides can be hit out but better to press them out, i would be removing the engine myself as they come out easy enough after removing the nose group, you can just unbolt the hydraulic pump and leave it in the frame still connected. tctractors

 

[sergioannis]

 

[sergioannis]

I removed the piston 2. It seems to me in excellent condition. The rings are like new. I have not found any anomalies. I think all that oil comes out of the valve guides .... I think.

 

[Vetech63]

Remove the oil control rings and put them in the bore of each cylinder (where each came from). Use the top of the piston to align the ring and measure the ring gap. It looks like the oil ring edges are scraped out. You can do the same with your compression rings. Post the measurements.

 

[kshansen]

Also is it just me or does that piston look strange up near the top?
Red arrow in picture below:


Been a few years since I worked on a D333 or 3306 but don't recall a piston that looked like that! Maybe a little cutting from the carbon like the black streaks but there apears to be a large amount of material missing on that side.

 

[Vetech63]

Looks like a burn

 

[Bluox]

Also is it just me or does that piston look strange up near the top?
Red arrow in picture below:

View attachment 242193
Been a few years since I worked on a D333 or 3306 but don't recall a piston that looked like that! Maybe a little cutting from the carbon like the black streaks but there apears to be a large amount of material missing on that side.

That's called a valve relieve or eyebrow pretty normal .
Bob

 

[Bluox]

Sergioannis
I think you are right that piston and rings look new.
Do you know the history of this engine?
almost looks like a valve guide broke and went threw the piston.
Any more valves loose?
How about a picture of the valve guide and the top of the liners?
Bob

 

[kshansen]

That's called a valve relieve or eyebrow pretty normal .
Bob

That's the problem with only seeing a picture and not having it in hand! From that angle I was thinking the top of the piston was eroded away.

Going back to see piston from top I can see the reliefs, but still looks a little rough around the outside diameter. Then again pictures can be deceiving!

 

[sergioannis]

Hi guys I cleaned the piston. It's new. it has a dent, I think something got in from the side of the air filter. For the rest I don't know what to say. I believe the cylinders are enamelled and the oil rings don't work. There is no crest on the cylinders.

 

[kshansen]

Have you pulled the valves out and cleaned them? Do you have spec's for the valve guides and valve stems?

Just incase you don't Ill attach a .pdf for them:

 

[Nige]

I cleaned the piston. It's new. it has a dent, I think something got in from the side of the air filter.

Are the valves and valve guides for that cylinder intact.? No small pieces missing.?

 

[Dave Neubert]

n wiggle the valve in the guide it is too lose

 

[sergioannis]

When I clean the valves I expected a lot of coal. Instead, with the drill, a rust color came out.
The residue I removed looked like sand-colored flour.
Could it be dirty fuel?
I didn't find any kind of crack in the valve guides.
it is likely that something has entered in the suction phase, some stone that has struck on the head .. I think
all this regardless of oil consumption and oil leaking from the exhaust.
I have to admit that the engine is in very good condition, I'm talking about the pistons, cylinder head and also the cylinders. I think he did not have too many hours.
What to say ....

 

[Cat977]

I'm with Bob on the vale guide being damaged and sending little bits down stream. The vale you you were moving around looked like a friend that needed a ride home. Also looks like you could pour some good oil past that valve. Time to take a good look before putting it back together. Seems like there maybe some good parts after your brush from out in the field agony.

 

[Nige]

When I clean the valves I expected a lot of coal. Instead, with the drill, a rust color came out.
The residue I removed looked like sand-colored flour.

I would say that is sand colour is normal and indicates good combustion. Black deposits would indicate poor combustion. Because your problem is recent there has not been the opportunity for black soot deposits to accumulate.

 

[sergioannis]