internal combustion engine stuck valves 1

[Luis_Villacres]

We own natural gas engines (Waukesha), sometimes the exhaust/intake valves were stuck in the valve guides, Do you guys know the causes and solutions to solve that issue?

 

[TugboatEng]

Are you using OEM or aftermarket parts?

 

[LittleInch]

Some sort of contaminant in the gas?

what does Waukesha say?

 

[gruntguru]

Assuming factory parts and clearances, the sticking will most likely be the result of contamination buildup. Because you have a problem with both intake and exhaust valves I would look at your lubricating oil. Does it have adequate solvency to remove varnish-like contamination?

 

[dtimberlake]

Have the engines always done this?
Do they all have valves that stick?
How old are the engines?
Have you done oil analysis on engines whose valve(s) have stuck?
Do the valve(s) stick when in service, or when re-starting immediately after shut down , or when starting after sitting a week or 2?
Is it always both the intake and exhaust valves on the same cylinder?

When valve(s) stick what do you do?

1. Let the engine run on 3 or 5 cylinders, until the valve(s) un-stick.
2. Remove the cylinder head and repair it in your shop? What do they find, and what do they do to put the head back in service?
3. Send the head to a machined shop for repair? What do they find, and what do they do to put the head back in service?

Whoever removes the valves and inspects the valves and guides will be able to tell if the problem is deposits, scuffing and seizing, or etc.

I had a car once with "wet" cylinder liners that allowed a little coolant into the oil. The coolant reacted badly with the oil and deposits formed on the valve stems that kept the valves from seating until the engine warmed up for 10 minutes or so. Refer to Item 1. Above.

 

[TugboatEng]

A great way to end a conversation about troubleshooting engines is to start by asking about the source of the parts.

 

[dtimberlake]

OP ain't been back since the day of joining, and the post, Jan 8.

I guess the problem has been solved.

I would have liked to see some pictures of the freshly stuck/un-stuck valves and guides.

 

[TugboatEng]

As an I. As a fleet operator of diesel engines, the valve material technology is so good nowadays that we no longer do valve adjustments. We do valve checks. Any change in settings should be interpreted as a failure and dictate a cylinder head replacement. Stuck valves are never a problem with diesel fuel. Natural gas may include digester gas which is loaded with silanes. I know they accumulate on piston crowns. I don't know about valves. I don't burn digester gas.

 

[Luis_Villacres]

Are you using OEM or aftermarket parts?

Yes, we are.

Everything come from INNIO

 

[Luis_Villacres]

Some sort of contaminant in the gas?

what does Waukesha say?

Some sort of contaminant in the gas?

what does Waukesha say?

I attached pictures and gas analysis, Waukesha does not say any concrete ideas, just generic solutions. Oil analysis does not show any normal trend

 

[Luis_Villacres]

Assuming factory parts and clearances, the sticking will most likely be the result of contamination buildup. Because you have a problem with both intake and exhaust valves I would look at your lubricating oil. Does it have adequate solvency to remove varnish-like contamination?

Hi, oil analysis is normal

 

[Luis_Villacres]

OP ain't been back since the day of joining, and the post, Jan 8.

I guess the problem has been solved.

I would have liked to see some pictures of the freshly stuck/un-stuck valves and guides.

Sorry, I went back to work, some information is attached

 

[Luis_Villacres]

Have the engines always done this?
Do they all have valves that stick?
How old are the engines?
Have you done oil analysis on engines whose valve(s) have stuck?
Do the valve(s) stick when in service, or when re-starting immediately after shut down , or when starting after sitting a week or 2?
Is it always both the intake and exhaust valves on the same cylinder?

When valve(s) stick what do you do?

1. Let the engine run on 3 or 5 cylinders, until the valve(s) un-stick.
2. Remove the cylinder head and repair it in your shop? What do they find, and what do they do to put the head back in service?
3. Send the head to a machined shop for repair? What do they find, and what do they do to put the head back in service?

Whoever removes the valves and inspects the valves and guides will be able to tell if the problem is deposits, scuffing and seizing, or etc.

I had a car once with "wet" cylinder liners that allowed a little coolant into the oil. The coolant reacted badly with the oil and deposits formed on the valve stems that kept the valves from seating until the engine warmed up for 10 minutes or so. Refer to Item 1. Above.

NO, they have not
no, they do not, some of them
They are 55000hrs
Yes, We have ( oil analysis is attached)
They stick in service
Yes, it is.
We Send the head to a machined shop for repair, see the pictures please

 

[nuevavion]

Yes, we are.

Everything come from INNIO

Care to answer the rest of the questions from dtimberlake? A simple tear-down and inspection should easily answer why the valves are sticking.

 

[3DDave]

Looks like the valves are coked up. At 55,000 hours I am unsurprised they need a complete cleaning.

 

[Luis_Villacres]

Looks like the valves are coked up. At 55,000 hours I am unsurprised they need a complete cleaning.

Actually, the last overhaul was carried out at 42106 hrs, so that valves are there 13000 hrs

 

[3DDave]

What did the valves look like at the last overhaul? What did the overhaul do? What parts were replaced at the last overhaul? How often or ever were previous overhauls done? Were all the parts individually inspected to see that they meet the dimensional requirements of the as-new engine?


You say you own them - are they operated by you?

 

[mfgenggear]

Valves stick for several reasons.
Over heat and distorted
Bent valve stems.
Lack of lubrication.
Improper clearance valve stem to valve guides.
Improper spring pressure
Pitting, fretting,
Carbon build up, causing Improper operation

 

[TugboatEng]

I see a lot of corrosion in a port. Do you have multiple engines sharing the same exhaust stack/uptake?

 

[Lou Scannon]

Some Waukesha engines run pretty hot. Are your exhaust temps within the prescribed limits? I assume so, as I expect this is monitored in operation with programmed alarms/derates/shutdowns as needed but I'm just guessing. Oil analysis has been discussed. But, are you using a factory recommended oil? I assume so, but just asking since you haven't identified a probable cause yet.