Cat 951c engine, oil in exhaust manifold

[sergioannis]

I disassembled the oil cooler above the filter. it turned out completely clean. The system had a clean blue coolant. There is an oil cooler on the side of the water cooler, all clean. I must say that the system does not heat up and the indicators always remain on the green. My doubt remains. Can enough oil pass through the valve guides to end up in the combustion chamber? Or more simply it is a question of rings. because remaking valid guides is much cheaper and even simpler. This is the question, removing an engine is never rewarding. Removing a cylinder head is easy.

 

[Cat977]

Good info tctractors. Have the valve clearances been checked? I'm defiantly not an engine guy. Will the oil get pulled into cylinder if vales are not seating properly?

 

[Dave Neubert]

If your breather is clogged it can build pressure and force oil past guides and yes valve guides can make oil come out the exhaust especially exhaust guides because the oil from them does not go through the combustion cycle when you had the manifold off was the oil running off the valve stems or coming out around the valve

 

[sergioannis]

If your breather is clogged it can build pressure and force oil past guides and yes valve guides can make oil come out the exhaust especially exhaust guides because the oil from them does not go through the combustion cycle when you had the manifold off was the oil running off the valve stems or coming out around the valve

it is clear that I have tested the engine:
without exhaust manifold
without valve cover
without air filter
I disconnected each of the diesel pipes (with the moltore on)
It could be that the intake valve guides are very damaged and the oil passes into the combustion chamber. Hypothesis only.
Looking at the engine without the valve cover, with the engine running, I see no problems and I don't see all this oil. Of course I couldn't try the engine at full throttle, this is because the oil would go everywhere. About halfway through the throttle a lot of blue smoke. So,
I decided to disassemble. I have to see .

 

[Cat977]

What would happen if the engine was run with exhaust valves too tight? I would guess they'd warp seat or stem. If the guy ahead of you then reset the valves. What would happen? Warped valve or stem would be bad compression and also have bad blow by correct? Could the piston pull in oil through the exhaust guild from having warped valve or stem after the ignition and before the exhaust stroke.

 

[tctractors]

This might help??? Go to page 12 in Shop Talk, then go to page 36 in Cat Sprocket Removal, then look at the pictures, your slobbering cylinders should have healed up after a few hours hard work unless it has pistons like this. tctractors

 

[Nige]

You mean this one Tony..?

https://www.heavyequipmentforums.com/threads/caterpillar-sproket-removal-also-komatsu.41705/page-36

 

[Cat977]

Tony
I can see how some buggered up pistons can still be going up and down with the help of lots of oil!
Shawn

 

[tctractors]

This was reported to be a Rebuilt Engine, so I was slightly shocked to find this damage, the engine ran well just heavy on the oil. tctractors

 

[sergioannis]

 

[sergioannis]

Hi guys ,
this and the 951c
As you can see in the last photos, to remove the plate under the oil sump, it is necessary to lift the engine at least 3 centimeters to remove the bolts. Unfortunately .
I did not understand the pin that should close the rocker arm shaft, from the oil spill.
Where is it ?

 

[Vetech63]

A video of this engine running at idle and fast idle is needed. Something isnt making any sense to me.

 

[sergioannis]

Hi guys ,
here, I created a private video in hd.
If you look at it all you can see and hear the strange sound of the engine. He seems to be coughing. I also framed the exhaust manifold and a few minutes already a leak.
As already mentioned, no blow by even at full throttle. This makes me suspect. I have seen engines, and usually bad rings give a very evident blow by. So listen to you experts who surely have much more experience than me.
I'm planning the disassembly. I'm taking some time.
So, if a piece of advice comes up before you take it all apart it would be great.

 

[Vetech63]

Hi guys ,
here, I created a private video in hd.
If you look at it all you can see and hear the strange sound of the engine. He seems to be coughing. I also framed the exhaust manifold and a few minutes already a leak.
As already mentioned, no blow by even at full throttle. This makes me suspect. I have seen engines, and usually bad rings give a very evident blow by. So listen to you experts who surely have much more experience than me.
I'm planning the disassembly. I'm taking some time.
So, if a piece of advice comes up before you take it all apart it would be great.

Ok, NOW this is making some sense!
1. The engine isn’t running smoothly, it’s missing a cylinder.
2. The smoke you are seeing is unburned fuel from a dead cylinder.
3. Are you positive that is oil that is leaking? Could it be carboned fuel?
4. I’m suspecting several possibilities.
A. The injector nozzle on #3 is junk.
B. If above is the case, that cylinder is washed down and can’t build enough compression to burn the fuel.
C. Washed down cylinders sticks all the rings allowing oil to pass the piston.
D. Possibility of a burned valve or broken seat.

At the very least you will need to pull the cylinder head. You can replace the nozzles as a cheap check but I’m afraid it’s too late.

 

[Bluox]

Holy sheep shitt ,If this is a good sounding motor I would hate to see a bad one.
Sounds like a piston is trying to swap holes.
pull the head and see what the carnage may be.
Bob

 

[tctractors]

Turn the Fuel tap off at the tank, follow what I said about jacking up the engine and drain down the water from the block and rad, by the sound of the engine it's about due to swallow a valve, when you get the pan off pin the Flywheel at TDC and check the Lanchester balance shafts for position by inserting the bolts through the Sump plate,I am not saying they are not set correctly but it will give you a confident lift when you reassemble things as to how they should be, as you will be removing the oil pump to draw off the Sump Plate. tctractors.

 

[sergioannis]

Hi guys . In the meantime, thanks to everyone for the support.
I removed the cylinder head.
The gasket is like new.
Before disassembling I eliminated the exhaust.
I could see that the cough was coming out of cylinder # 2. During the strange explosion you could see sparks like fire. I could not tell if the oil was coming from the valve guide. The cylinders are mirrored and the pistons are all in all good.
I attach video of the valves and images of the cylinders and cylinder head.
That blowout ??????

 

[sergioannis]

 

[sergioannis]

 

[Welder Dave]

Ciao ragazzi . Intanto grazie a tutti per il supporto.
Ho smontato la testata del cilindro.
La guarnizione è come nuova.
Prima di smontare ho eliminato lo scarico.
Potevo vedere che la tosse usciva dal cilindro n. 2. Durante la strana esplosione si potevano vedere scintille come fuoco. Non riuscivo a capire se l'olio provenisse dal guidavalvola. I cilindri sono specchiati e i pistoni sono tutto sommato buoni.
Allego video delle valvole e immagini dei cilindri e della testata.
Quello scoppio??????

English please.