I've read that one of the characteristics of Direct Injection is coking of the valves. The suggested reduction of the coking is the use of a Catch Can or Air/Oil Separator. Has anyone installed either and what brand and results are you experiencing?
Thank you
2014 F-150 3.5L Ecoboost at 32K

 

http://lmgtfy.com/?q=catch+can+f150+forum

You will find lots of results...

 

 

This has been beat to death. Some say run a catch can, others say its a waste. I run one. The crud it catches is pretty nasty.

The CRC GDI spray is new to the market. I bought a can but have not tried it yet.

 

The crud that comes out of mine is disgusting as well. Mine was installed prior to me purchasing the vehicle used.

Mine is an RX catch can. I would suggest the mega version if you buy one of their products.

I also tried the CRC GDI cleaner and didn't have any good/bad issues with it. Didn't really notice much of any difference.

 

I have a catch can and do not think its a waste of money. Its unbelievable how much is recycled back into your motor. This is a picture after one full tank, water, gas, and oil.

 

Coking occurs from incomplete combustion and you'll get soot, or carbonous material buildup in the DI, and carbon monoxide pollution. Coking is typically reduced by elevating pressures or introducing a hydrogen rich stream (which means a higher octane gasoline). Along with burning more efficiently, the hydrogen reacts with carbonous gunk and thus helps deplete the coking by binding to the gunk and leaving. Low octane gasoline however, has lower concentrations of hydrogen which causes more incomplete burning and thus a larger amount of soot buildup will occur. The takeaway from that point is use higher octane gasoline to help prevent coking (super unleaded); it'll help burn the soot off while simultaneously binding and removing.

Coking typically occurs in DI valve because of the incomplete combustion after the fuel is sprayed. When coking occurs in the DI valve, it clogs the oil or makes it more viscous, causing the car to lose efficiency and suffer from wear and tear. Besides using super unleaded gas, make sure the fuel pump is working properly to ensure that the fuel pressure is high enough... if its low that will also promote coking.

An oil with additives that reduce viscosity would be beneficial to help oil pass through the coked area of the valve more easily, helping to maintain the car efficiency.

An oil that acts as a coating for the DI valve could also be beneficial so that carbonous material cannot stick to the valve, basically making your DI valve a non-stick pan (as they probably advertise).

Hope this helps in choosing.

I'm a chemical engineering student that doesn't know jack sh#t about cars, kinda. I just did some research made some pretty educated assumptions. Correct me if I'm wrong but I'm pretty damn sure I have the general premise right.


Someone please correct me if their experiences say otherwise.