Symptoms of dirty pistons?

[Sienna dude]

What are they?

 

[BMWTurboDzl]

What are they?

Stuck control rings would allow for oil consumption

 

[Propflux01]

Excess blowby on a relatively non-worn engine.

 

[jetman]

In 2018 we bought a used vehicle that was consuming 1-2 qts of oil per 3000 miles. Here is what all 8 spark plugs looked like. I did a piston/combustion chamber soak, and a technical service bulletin which ended the consumption. 70k miles later still going. strong

 

[frankbee3]

In 2018 we bought a used vehicle that was consuming 1-2 qts of oil per 3000 miles. Here is what all 8 spark plugs looked like. I did a piston/combustion chamber soak, and a technical service bulletin which ended the consumption. 70k miles later still going. strong
View attachment 286755

Was this a GM LS series engine? Sounds like an interesting repair. I think I read here on BITOG about an updated valve cover for the LS engine that improved the PCV system? Do you have a link that you can point me to that describes what you did to correct the oil consumption?

 

[GSCJR]

Was this a GM LS series engine? Sounds like an interesting repair. I think I read here on BITOG about an updated valve cover for the LS engine that improved the PCV system? Do you have a link that you can point me to that describes what you did to correct the oil consumption?

+1

 

[jetman]

Was this a GM LS series engine? Sounds like an interesting repair. I think I read here on BITOG about an updated valve cover for the LS engine that improved the PCV system? Do you have a link that you can point me to that describes what you did to correct the oil consumption?

Yep, I've posted about it here before with our 07 Yukon Denali.
https://static.nhtsa.gov/odi/tsbs/2014/MC-10114272-9999.pdf

 

[RDY4WAR]

Low power
Oil consumption
Dirty/coked plugs
Excessive blow-by
Quicker oil oxidation

 

[frankbee3]

Yep, I've posted about it here before with our 07 Yukon Denali.
https://static.nhtsa.gov/odi/tsbs/2014/MC-10114272-9999.pdf

Thanks Jetman! It is now my homework assignment.

Off topic, but do you still have your Glasair TD? I imagine that landing and takeoff speeds are kind of fast? Do you 3 point or wheel land your Glasair?
I never did fly the Glasair series of airplanes, but did once get a ride in an O-320 powered Lancair that a friend has. I had an RV4 for 16 years. I miss that plane more than any plane I've had.

 

[fantastic]

Added wear when the rings get loaded with soot etc behind the rings in the ring grooves. Clogged oil return holes on the piston.

 

[Glenda W.]

Believe me it’s not fun dealing with an oil burner. I was lucky to remove the deposits with R&P but really makes one think of running an oil like HPL or Amsoil in an expensive new car. In my case this was the first time dealing with stuck oil control rings with 5k oci’s and synthetic oil. Prior to this I believed any approved synthetic was good enough. Unfortunately it’s not the case and more common now.

 

[Sienna dude]

Added wear when the rings get loaded with soot etc behind the rings in the ring grooves. Clogged oil return holes on the piston.

Soot does show on UOA, right? And in the filter?

 

[jetman]

Thanks Jetman! It is now my homework assignment.

Off topic, but do you still have your Glasair TD? I imagine that landing and takeoff speeds are kind of fast? Do you 3 point or wheel land your Glasair?
I never did fly the Glasair series of airplanes, but did once get a ride in an O-320 powered Lancair that a friend has. I had an RV4 for 16 years. I miss that plane more than any plane I've had.

Yes I still have it.
Mostly wheel land it.
In the 3 point attitude you can't see chit.
The RV series of airplanes are great. I've flown the 4, and 6.

 

[OVERKILL]

Soot does show on UOA, right? And in the filter?

Soot can pass through a filter, and GDI soot is finer than diesel soot, as a study I posted an excerpt on some time back gets into. When a lab such as OAI/Polaris tests for soot, that's diesel soot, so I'm not sure how well that works for GDI soot, which is different. And of course not all labs test for it.

 

[Sienna dude]

Low power
Oil consumption
Dirty/coked plugs
Excessive blow-by
Quicker oil oxidation

Low power: Negative

Oil comsumption: Negative

Dirty/cooked plugs: Negative. I regret why I changed them.

Excessive blow-by: A little bit in the filter

Quicker oil exidaton: Not sure. I change the oil way before it gets to anything close to not neinh serviceable. Last time I changed the oil TBN was 6.8

 

[SwampSurvivor]

In 2018 we bought a used vehicle that was consuming 1-2 qts of oil per 3000 miles. Here is what all 8 spark plugs looked like. I did a piston/combustion chamber soak, and a technical service bulletin which ended the consumption. 70k miles later still going. strong
View attachment 286755

Wow .. my eyes deceived me there. I thought that was a mushroom cloud behind a pair of fence posts.

That's some crazy oil !

 

[kschachn]

Soot can pass through a filter, and GDI soot is finer than diesel soot, as a study I posted an excerpt on some time back gets into. When a lab such as OAI/Polaris tests for soot, that's diesel soot, so I'm not sure how well that works for GDI soot, which is different. And of course not all labs test for it.

Aren't they just testing for opaque particulates in the oil?

 

[OVERKILL]

Aren't they just testing for opaque particulates in the oil?

Not sure, but I know they are MUCH smaller particles than diesel soot, so I suspect this is why we don't see meaningful values for soot on GDI engine UOA's.

 

[kschachn]

Not sure, but I know they are MUCH smaller particles than diesel soot, so I suspect this is why we don't see meaningful values for soot on GDI engine UOA's.

I also think he meant is there a test in a standard UOA or a spectrographic component that shows soot, which there isn’t.

 

[fantastic]

Soot does show on UOA, right? And in the filter?

Yes, there are soot tests that can be done on a UOA. Filter by eye mainly.