Caterpillar 951c water in oil and in cylinders.

SHEEESH!!!! yes those precombustion chambers are toast! replace all four. Also check the sealing surface in the head where the chambers fit, they should be clean and smooth with no pitting. The pitting on top of the piston looks ok yet, thats from the coolant. The chambers get torqued to 200 ft lbs. Have the head checked for cracks and correct valve seat height. Might need new valves and guides also.

Cylinder liner bottom seals are also a candidate to allow water in to the crankcase although in this case it appears to be leaking from top side. Not running proper coolant (as in straight tap water) accelerates the corrosion.

Hi ,Cylinder liner bottom seals , can i replace now that i removed the head?

Thanks

Cylinder sleeves need to be removed to replace the lower seals.
Cylinder sleeves also need to protrude slightly above the engine block to seal the head gasket.

ok too complicated.
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In the headquarters of the prechamber I noticed that where the seal goes there is quite ruined. how can i solve? can I put, besides the new steel gasket, also of the mastic for high temperatures?
do I have to file the head?
You know the correct tightening torque of all bolts in nm.
sorry for all these questions ...
thank you

A good machine shop may be able to resurface those areas. The upper seal area could be cleaned up with a flap wheel on a die grinder. Have the head checked for cracks first.

I only know the correct way to repair and that is to have the chamber seats spot faced (machined) and corresponding shim sealing washer used to restore the chamber height so that it does not protrude into the combustion chamber. If the head is not warped it does not need to be resurfaced.

Hi uisum,
a closeup photo of the combustion face of the cylinder head would help us to see where the water may have gotten into the combustion chamber/piston top areas. Any rust pitting on the cyl. head combustion faces can help determine this.

Rust pits on the cylinder head surface around the Pre-combustion chamber threads/hole can mean the pre-chamber seal gaskets have rusted thru and/or the cylinder head could be cracked at the pre-chamber thread holes.
Heads can crack in and around the valve seats too as well as down into the inlet/exhaust valve ports if the engine has been overheated.

If the cylinder head and pre-chambers are not faulty then as well as the lower liner seals that require removal and part dismantling the engine to fit new ones.

The engine oil cooler on the side of the engine can have cracked cooling tubes that let oil into the water and also the other way when the engine is not running.
The oil cooling tubes can also block with debris on the water side and cause low water flow in the engine and so can be a cause of overheating.
Cheers,
Eddie B.

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Hello. bad news.
I found these cracks in cylinder number 3.
a crack that goes from the pre-chamber thread, and another that goes to the smoke vent valve.
how to solve?
I am thinking of welding and breaking away.
can I use some repair system?
thank you