oil buildup

[robeward]

this is technically on a Volvo setup but really just looking for information.

in the pictures you can see black buildup on the blades of the flame arrestor and on top of it. You can also see some oil on top of the valve cover.

is this normal?

are those hoses coming from the valve cover the same as a PCV system on an automobile?

 

[Scott Danforth]

normal, the elbows are exactly that, elbows.

your engine has a bit of wear, and a bit of oil that normally is burnt is sent to the flame arrestor.

 

[Watermann]

Replace that worn/hardened grommet with a new one in the valve cover to stop the oil from bypassing it and getting on the cover. Also try to reposition the flame arrestor so the hose doesn't pull on the elbow and create a gap. It also looks like the hose is the wrong inside diameter, that's a big gap at the arrestor. The venting of crankcase is whats causing the arrestor to turn black, if need be clean it more often because like Scott says your motor could be just showing it's age.

 

[robeward]

so this is a little unnerving as the engine is practically brand new. only 179 hrs as of this past sat.

so this is PCV or not? scott are you saying the elbows are basically just 90s, nothing special to them?

waterman where is this grommet? at the base of the elbow?

thanks for the help.

 

[Watermann]

The grommet is in the valve cover but if the motor is that new then I doubt it's hardened, rather the positioning of the arrestor is putting uneven pressure on the elbow or the hose doesn't fit the nipples. Also yeah that's just a plastic elbow, not a PCV valve. It the last pic you can see that the hose looks over sized for the nipple on the arrestor. Take the arrestor off and clean it, that's a lot of hours without cleaning the gunk out of it with a can of carb cleaner. When you put it back on position it to where the hose isn't pulling/pushing on the elbow creating a gap in the grommet where the elbow goes in. If it were me I would replace that hose with one that fits better and use a spring clamp instead of a cable tie.

 

[robeward]

gotcha. so it typical maintenance to take the arrestor off and clean it? i would say it has been on for about 100hrs without a cleaning.

so what is the purpose of the hoses going to the arrestor?

 

[Watermann]

gotcha. so it typical maintenance to take the arrestor off and clean it? i would say it has been on for about 100hrs without a cleaning.

so what is the purpose of the hoses going to the arrestor?

I would clean the arrestor more than once a year if it started looking black. You'll be amazed at how much gunk will come out of it.

Crankcase emissions are burned rather than vented.

 

[robeward]

got it. it will get cleaned this weekend

 

[Scott Danforth]

the hoses running to the spark arrestor do the samething that the PVC valve does in an automotive situation. it helps extract the blow-by in the motor. and yes, even brand new motors with 0 hours on them have some blow-by internally. there is no such thing as a set of rings that seal 100% of the combustion chamber. 99.9%, however not 100%

 

[robeward]

got it scott. thanks. i have recently been reading about PCV dealing with my truck. i figured that was the purpose of the hoses but wanted to make sure. i also just wanted to make sure nothing appeared out of the norm.

i have been reading about people adding 'catch cans' to their trucks to catch the blow by instead of burning it. seeing how much stuff has collected in my boat makes me a little more of a believer that the cans are worth it.