David Jones

I've read about how the Ecoboost engine WILL coke up....just like every other DI engine built. Daily somebody logs on here asking what to do to prevent this from happening to their baby. I read about preventative measures and what to do to cure it when it happens to your truck.

I don't recall reading about an actual case.

Anybody having a carbon issue?

emerilnut

"Coking" for me is a different term that applies only to turbos, and it's something that I have thought about for this truck from time to time.

Coking happens when the oil going through the turbo itself gets very hot and then basically stops flowing through when the engine is turned off. Therefore, the oil that gets stuck in the hot turbo basically cooks into a solid. Over time that solid layer gets thicker and thicker and starts to restrict oil flow through the turbo to cool it. What turbo guys have done for years and years is adopt the practice of letting the car idle for about a minute after parking to let the turbos cool down before turning the engine off. There have also been devices like the Turbo Timer invented that will leave the car on and turn the ignition off after a pre-determined amount of time after the key's been removed. Also, there are water-cooled turbos that can minimize the coking problem. Fortunately, the Ecoboost turbos are cooled by both oil and water.

I think what you're referring to is the carbon buildup on the back of the intake valves due to the "dirty" intake our PCV system creates by recirculating blowby gasses into the intake. And yes, the problem is mainly because of DI and a total lack of a "shower spray" effect that port injectors have to clean the valves. It is definitely a problem on the DI trucks, and the remedy seems to be oil catch cans.

The problem with this carbon buildup issue is that I think it would be hard to diagnose an actual problem. The symptoms would really only be loss of power over a very long period of time. And of course if you ran a compression test, it would show low cylinders I'm sure. I guess some major problems could happen, but they would be the extreme cases, and therefore there would be fewer of them.

When I was shopping for my new truck, I was debating used or new, but I definitely wanted a 2018 or newer since that's when Ford switched to dual injection.

David Jones

Any actual cases of this on this forum?

Gozuki

iTrader: (6)

Gen 2 began in the 2017 models.

Probity

Your question will probably draw many answers. 99.99% will be “nope never seen a carbon problem yet”. It will also invariably lead to the dreaded “catch can” debate, which does not need to be brought up again as there are probably thousands of replies on that. Not gonna go there. And the use of Seafoam or other like-products. To my knowledge, still a non-no with turbos according to FoMoCo.

There will also be lots of opinions (vs. verifiable facts) thrown out. Believe what you want, ignore the rest.

I was one of “those guys” before I bought my ’16 with 3.5L EB that wondered if I should be concerned about carbon buildup, and what (if anything) I could do about it. I traveled down the catch-can info road for quite awhile, and finally decided I didn’t want it/need it. Then I traveled some more down the DI injection info road and concluded (a) yep it has happened on some DI engines, (b) very little mention of actual Ford EB engine cases with “bad” carbon buildup. And there was always the question of how the EB engine with reported “bad” carbon buildup was driven, did it have a tune, what gas did they use, etc etc. So I bought my 3.5L EB (last of the 1st gen without PFI and DI).

In a few articles I read on DI engines (not Ford) and carbon buildup, it seemed one conclusion was common – the lower the engine load, the more carbon deposit.

So, some poor-boy practices I choose to follow:

1. Keep using good Top Tier gas (stuff with detergents). Won't help carbon on intake valves but will hopefully keep injectors clean, maybe help minimize combustion chamber carbon deposits.
2. Oil changes with a good Group IV oil. Seeing too many articles on motor oil effect of carbon buildup in DI engines. I know everyone has an oil type/oil change interval opinion, I have mine, you have yours, whatever floats your boat...once GF-6A oils come out I may start using them.
3. The occasional "Italian tune-up" as conditions permit. I'll still use cruise control on long interstate trips if traffic allows, but a few WOT's will make the trips a little more fun.
4. Avoid (to the extent practical) putting around town/idling at low rpm’s for extended periods. Sport Mode is my friend there. Basically, try not to go long periods with very low engine load.
5. Checking/changing the spark plugs well before the 100K miles mark, unless start seeing noticeable fuel economy/performance degradation before then.

The newer EB's with both PFI and DI seem designed to minimize carbon buildup. But I was surprised though when I read a few articles on them where Ford engineers claimed it was mainly done to minimize particulates in emissions. More of an EPA thing than a "let's prevent carbon buildup!".

"Your Mileage May Vary"

bcb97

No. And Probity's practices are good to follow. My tuner, MPT, recommends pretty low intervals for spark plug change. I believe it's 10-15k but it says it somewhere specifically on their website. I change mine at 15k currently.

I've also heard/read somewhere that the specific patent of Fords DI does something where they open the intake valve slightly as fuel is directed in the cylinder to possibly allow fuel to reach the back of the intake valves. I'm not 100% sure about that but it was along those lines that I read it.

brandon\

Yeah, but do you think Ford (or any other auto manufacturer) would come out and say “We screwed the pooch on millions of engines we just sold. Please don’t loose confidence in our ability to make solid stuff.” Of course they will say something like that - and EPA emissions stuff is a low hanging fruit.

moparado

This^
I'd bet most people with high mileage DI trucks who have considerable carbon build up on the intake valves don't even know it but do notice their engine is not as peppy as it was when new.

Take the oil burning '18 5.0's.
The official Ford root cause explanation far as i know is still unknown... its secretly hidden safely away in some Ford corporate vault.

acdii

With well over 1,000,000 3.5 Ecoboost engines built as of 2016, no one has yet produced photographic evidence that the intake valves on the 3.5 Ecoboost carbon up. I have seen pictures of carboned up valves, but on closer inspection, they were not from the Ecoboost.

Coking of the oil passages in the Turbos will never happen due to the way the coolant system flows through the turbo, it uses convection when the engine is shut down to have the coolant continue to cool down the turbo. Back in the 80's/90's when a Turbo was slapped on a NA engine, and usually set on top of the engine, oil would drain from a still spinning turbine, quickly wearing down the bearings, and coking what little oil remained. Back then I must have replaced dozens of turbos on all makes/models of cars, including the well made Subarus.

David Jones

500 views.
As often as this forum is reminded that the Ecoboosts are prone to this issue.........anybody?