Catch can on the 3.5 DI motor?

[Chipster]

Has anyone installed a catch can on their 3.5 DI engine? It seems there is ample justification for the use of these things given the plumbing of the PVC stream into the intake track and the oil vapors which are drawn past the intake valves. Anyone have any experience with one on the 3.5?

[WWWPerfA_ZN0W]

The catch can question is rather elusive. It seems to be more dependent on which variant of the 3.5 EB you are referring to. The F150 variant setup seems to need the catch can far more than the SHO/Flex/XSport variant, at least after initial breakin is over. With the redesign of the transverse engine's bank 1 valve cover, the problem seems to have been ameliorated to a large extent. ONE of the theories out there is that it is actually the compressor seals on the Borg Warner turbos on the F150 are weaker than those on the Garrett turbos on the transverse variant.

 

To see if you need a catch can, you can check:

a] the MAP sensors for oil accumulation

b] the intake tract for pooling oil

c] the intercooler for pooled oil/fuel/crud

[Chipster]

Very thoughtful answer, thanks! You are right about the question being elusive, and the answer seems to be even more so. I am wondering about the 3.5 installed in the 2015 Edge. I've seen images of the "catch contents" removed from catch cans installed onto DI motors across the spectrum of brand lines and I am amazed at the amount of condensed oil & water vapor that these catch cans remove from the pcv stream. It does make you wonder what the back sides of intake valves on these DI engines will look like after 50K mileage without some way to remove those vapors?

Edited September 11, 2015 by Chipster

[WWWPerfA_ZN0W]

Hard to tell. If the redesigned valve cover from the SHO has had an impact on the production valve covers of the 2015 Edge, it should bode well for the PCV system in the Sport.

 

For the 3.5 NA engine, you can use a catchcan, no idea how much it is needed. Just like on the DI motor, you would run a "clean"side collector as well as a "dirty"/PCV-valve-side collector into the catchcan (preferably with builtin drain arrangement), which would be mounted in a cool location, same as you would for a Cold Air Intake, to maximize oil vapor condensation/collection. You could also take off the fresh air tube that runs from the intake to the bank 2/front valve cover and put a breather on there. The "cleanside" is usally 5% of the problem, the "dirtyside" 95%.

 

On my 2007, I have found the throttle body and intake piping to be pretty dry/oilfree, FYI.

[Chipster]

I had incorrectly assumed that the 3.5 was a DI motor. It is not, and is a throttle body controlled engine. The issue discussed above is covered by this video though it is mainly about DI Eco engines.

https://www.youtube.com/watch?v=-ynGWxzJHjA

Edited November 6, 2015 by Chipster