[White95Cam]

On a recent episode of Motor Trend, Pat Goss was talking about the build up of intake oil deposits in direct injection engines since the fuel wasn't flowing through the intake. He also talked about the oil consumption that was occurring and upsetting owners with some newer engines. It is related to the use of low tension rings to increase MPGs. Crankcase oil vapors are gumming up the rings and causing the oil use. He also stated that manufacturers are aware of this and that is why they say oil consumption is now considered normal.
He had his personal Camaro in his shop and low and behold he had installed a catch can system on his new car to trap the oil from the vapor before it was ingested into the engine. It was a nice one out of billet aluminum with braided lines.
His recommendation was to install a CC system in all newer cars to prevent the gumming problem. He is a reputable person so I think he knows what he is talking about. It certainly should keep the PCV valve clean and the rings as well.
W95c

 

[toyotaspeed90]

Blaming direct injection really isn't the right path...... that may be accurate for V type engines that use simple fuel methods (TBI, carburetor) where fuel flows through the intake manifold, but any system that has basically 1 injector per cylinder won't have fuel running through the entire intake manifold. The only exception to this might be certain older models that have an archaic (it's archaic, but it did work well) cold start injector....

Take your 95 Camry..... both of the engine options have multipoint injection (one injector per cylinder)....

the PCV valves should have far less vacuum and run pre-throttle body - so any positive oil crankcase could carry oil into the intake tube.

Fuel for the injectors is at each port, at the end of the intake run.... if in the manifold at all. (I believe, for instance the very early 4afe in the Alltracs had the injectors in the manifold then moved to the head).

Here is a shot of a 90 4afe and 2 4age heads - the small hole above each intake is where the injector would sit - at an angle- and they are meant to spray at the back of the valves, not into the manifold:

My point with this is that the direct injection and fuel not running through the manifold isn't the culprit of causing oil from a pcv system to be burned more or not. Once oil is introduced into the combustion chamber - whether through rings, valve guide seals, or PCV systems that have way too much oil running through them... is going to come out the tailpipe.

 

[got-rice]

Motor Trend? I think you mean Motorweek

 

[White95Cam]

Blaming direct injection really isn't the right path...... that may be accurate for V type engines that use simple fuel methods (TBI, carburetor) where fuel flows through the intake manifold, but any system that has basically 1 injector per cylinder won't have fuel running through the entire intake manifold. The only exception to this might be certain older models that have an archaic (it's archaic, but it did work well) cold start injector....

Take your 95 Camry..... both of the engine options have multipoint injection (one injector per cylinder)....

the PCV valves should have far less vacuum and run pre-throttle body - so any positive oil crankcase could carry oil into the intake tube.

Fuel for the injectors is at each port, at the end of the intake run.... if in the manifold at all. (I believe, for instance the very early 4afe in the Alltracs had the injectors in the manifold then moved to the head).

Here is a shot of a 90 4afe and 2 4age heads - the small hole above each intake is where the injector would sit - at an angle- and they are meant to spray at the back of the valves, not into the manifold:

My point with this is that the direct injection and fuel not running through the manifold isn't the culprit of causing oil from a pcv system to be burned more or not. Once oil is introduced into the combustion chamber - whether through rings, valve guide seals, or PCV systems that have way too much oil running through them... is going to come out the tailpipe.

This was not at all in reference to my car. I originally posted this in the Gen6 section because of a thread describing the time consuming replacement of the PVC in the 2ARFE engine. I thought it might also help with the people having oil burning problems with the older engines under recall. The mods moved it here to this wasteland thread. Mr. Goss of Motorweek was proactively installing a CC to protect his new engine. That is all I have to say.
W95c

 

[White95Cam]

Motor Trend? I think you mean Motorweek

got-rice, Thanks for the "catch" as I watch them both. I haven't seen you in the gen3-3.5 forums for a while and didn't know what happened to you. You still have a Camry?
W95c

 

[toyotaspeed90]

I was only using your car as an example because you may understand that car pretty well if you're under the hood much, and to indicate that fuel not-passing through the intake manifold isn't a new process.

Now there could be something said that due to direct injection (or emissions) the piston rings have tighter tolerances - and as such, there is a much higher positive pressure in the crankcase which aids in oil passing through the system.... that may be a possibility. I have a hard time with the idea that fuel not passing through the intake manifold is a root of any problems, from a mechanical perspective.

 

[got-rice]

got-rice, Thanks for the "catch" as I watch them both. I haven't seen you in the gen3-3.5 forums for a while and didn't know what happened to you. You still have a Camry?
W95c

That's not me, I own a Corolla not a Camry...