All the newer engines used today that have Direct Injection systems that have no way to clean the intake valves unless you do it yourself or have someone do it for you. How many people out there clean there intake valves without using an oil catch can? I'm surprised that manufacturers don't install a capture system that returned captured oil back to the engines oil system, instead of the air intake system to coat the intake valves. What do you think?

 

It's probably because if you are having that much blowby a rebuild is needed.

 

That's what you would think, it's a 22 Silverado 6.6L gas. I bought it new with 40 miles on it, it just turned over to 30k last week. Engine oil always looks clean and never moves on the dipstick. I can drive it from Boise to Portland and the catch can will have maybe 1/2 a teaspoon in the bottom of the catch can. I'm thinking its catching crankcase vapor that would normally return into the intake manifold thru the pcv system to be burned as it oil coats the intake valves because of direct injection. It makes me wonder how much oil vapor engines are burning, new and old. I have always used pcv systems for years not really thinking how much oil is burned that way. The Chevy dealership answer to dirty intake and carboned cylinders is to run intake cleaners and fuel cleaners to keep the issue in check. But they don't disagree that an oil catch can would be helpful.

 

That's certainly interesting.

 

While I'm not against catch cans, I think a bottle of Techron every oil change is a lot easier.

 

That's true, I have used techron for years it does help to keep the fuel system cleaner, but with DI systems it doesen't help the intake valves and intake manifold carbon build up from oil vapor. Even with minimal blowby there is still the vapor. I have heard there are a few car manufacturers considering using port injection along with DI to help keep the carbon down on the intake valves. So I'm thinking using an air oil separator/catch can I can stretch out the intervals between carbon cleaning on all fuel systems and even carburation. It's been hot here in Boise lately, so it gives you more thinking time in the afternoons, Sorry for that.