Ford Ecoboost 3.5 Carbon build up

[Shade Tree Welder]

Interesting video.

https://youtu.be/sNzF7rm8OzY

[mccutter]

That is a good video showing the differences in deposits due to differing injection styles.

Mfgs went to Direct (gasoline) Injection into the combustion chamber to improve emissions and economy. With Ported Injection, there is a small distance that the atomized fuel must travel before it reaches the chamber, and it can coalesce and not burn as completely or efficiently as if it was still atomized. DI sprays directly into the chamber, improving combustion of the fuel.

The "issue" with DI is that it is no longer "rinsing" the ports and backsides of the valves, so deposits can tend to collect. It can get so bad they affect airflow into the chamber with resulting driveability concerns. There is always going to be a little "suck back" when the intake valves open and close--it is not entirely one way especially with high vacuum conditions (idle and cruise). Turbo or other boost methods can add oil mist into the intake ports just through normal function and increased pressure in the crankcase.

It looks as if Ford is trying to fix this issue by adding a port injector to the equation and it would appear to be working somewhat successfully.

A common "repair" for carbon buildup is called a "Carbon Cleaning" often involving walnut or other semi-abrasive blasting inside the ports. 100k miles is usually when this is done.

It just so happens I am about to pull the intake on my 2006 VW 4-cyl 2.0t 16v DI engine. The car has about 245k miles on it and the intake does not appear to have ever been removed so it will be interesting to see the carbon buildup. In fact, the bolts and intake are loose but the injector seals are still holding it in so I decided to quit for the night and review the manual to make sure I'm not missing anything.

This particular engine has flaps built into the intake right at the ports that partially close them off at low engine speed to increase velocity of the air going into the engine. This helps improve driveability, power and economy keeping in mind that most of everyone's driving IS done at low speeds. When the hammer goes down, the flaps open allowing max air flow. The flaps are controlled by a motor and I was getting a code that indicated the motor was not moving so it is very likely the flaps are carbon-ed up and stuck.

I'll update with pics once I get the intake off but I've really been milking this job. There is a bunch of other stuff needing to be done such as a clutch slave cylinder (needed) and timing belt (overdue scheduled maintenance) so I'll be pulling the engine/trans as one unit... The pic is from about a month ago--I'll have to dig up a more recent pic which really doesn't look that much different other than a few more things removed. I'm pulling the intake now as it is right there waist high and easy to work on standing upright.

[JH35]

Pardon me for not having any idea, but I have never had this issue with a diesel - 1950's John Deere mechanical natural aspirated through Detroit Diesel series 60 . Differences in fuel, combustion pressures and temperatures all have something to do with it I am sure.

[Shade Tree Welder]

Originally Posted by JH35

Pardon me for not having any idea, but I have never had this issue with a diesel - 1950's John Deere mechanical natural aspirated through Detroit Diesel series 60 . Differences in fuel, combustion pressures and temperatures all have something to do with it I am sure.

Because it was a diesel...

The carbon build up is from the port injection they added a second port injector
in the second gen ecoboosts. It helps but does not solve the issue completely.

I posted this in case any members have an ecoboost engine.

[JH35]

I spoke about the cleaning procedure with a co-worker that has a newer Tahoe. He has quite a few miles on it (maybe 80-ish K) with no issues on the direct injection. Maybe the boosted engines are more prone.

[Shade Tree Welder]

Originally Posted by JH35

I spoke about the cleaning procedure with a co-worker that has a newer Tahoe. He has quite a few miles on it (maybe 80-ish K) with no issues on the direct injection. Maybe the boosted engines are more prone.

Watch the video again you missed the design.

[JH35]

My apologies, I didn't notice the video. I just saw a few words and skipped ahead like I always do. Sometimes I miss things. ADD? who knows. I will watch it today. Thank you.