My 08 LR3 was stumbling as the butterfly closed. I cleaned the throttle body, and all that went away (AND my mileage improved! Not sure how much yet, but I think >5%).

But I also watched this video and Storey complains of a lot of oil ahead of the butterfly. This makes sense to me and I think you WANT some oil mist ahead of the butterfly. I don't think you can make the engine breathe by putting the port behind the butterfly, because then you'll create so much vacuum in the engine, you'll pull the valley gasket down into the engine (or at least make it leak). But mine was totally clean ahead of the butterfly (no oil), and dirty and scaly after it. So I think my engine is not breathing properly. Correct?

1) If you did this service, were you getting some oil ahead of the butterfly? I would think you should have some as the oil mist is burned.

2) Is the PCV just a trap like the old Rover V8s, or an element that opens and closes? I couldn't get my hose off.

Thanks!

 

The hose before the throttle is a breather hose. It is there to allow filtered air from the MAF sensor into the crankcase. The crankcase is connected to the intake vacuum source via the Pressure Regulator valve on the right bank valve cover. This valve is what keeps full manifold vacuum from the crankcase.
High speed engine operation often causes oil mist to come out of the breather hose, this is perfectly normal.

 

Yes, I would expect oil too. The fact that mine does not have oil is worrisome, and I think the inside of the intake looks dark and crusty, like the engine is not staying ventilated. I had a hard time undoing either end of the air hose I'm talking about (with little clips on each end). It was only about 10°F out when I cleaned it (my Classic is taking up too much room to work in the garage :-). If I find no trace of oil, I guess I'll have to try to find the regulator and see if it is opening. I was thinking if I could get the end of the hose off whatever it was connected to, I was going to find a typical PCV valve, but I couldn't get it apart. Have you ever seen one with NO oil? I think that means something's not right.

 

Because seeing some oil is normal, that doesn't automatically mean that the lack of oil is a problem. Fact is, most of the ones I take the air intake off of, are NOT wet with oil. I was merely letting you know that if you DID have some, its OK.

To test if the Regulating Valve is flowing anything, just remove the oil cap while its running. If the idle changes (due to increased unmetered air), its flowing.

 

When I cleaned my throttle body, if I remember correctly, it seemed like most of the accumulation was on the back side. The front was significantly cleaner.

Front being the side ahead of the butterfly.

Oddly enough, I never got any stumbling or poor fuel economy. I got a "reduced engine performance" print out on the display which caused me to go investigate.