Re: Ford EcoSport : Official Review Quote:
Originally Posted by k.sumit An interesting thing to note there was when a question was asked on how to deal with carbon deposits in direct injection engines. In response, the guy from Maruti recommended to use a special additive every 20k kilometers to flush out carbon deposits and they will do this at MASS during the service itself as a part of schedule maintenance. My guess is, they were discussing carbon deposits on valves but I could be wrong. |
Very good question. What you've mentioned is the carbon build-up that happens on the back of the intake valves of all direct-injection engines, not just the EcoBoost.
It sounds counter-intuitive - in a direct injection engine, the intake valve only lets air in, and the fuel is directly injected into the cylinder (unlike MPFI engines where the fuel-air is mixed in the intake header and this mixture is passed through the valve). So, where does the carbon come from? Well, the crankcase and valvetrain areas have a fine oil mist that is produced by the crankshaft churning oil, and other oil vapours (apart from blowby from the cylinder past the rings into the crankcase). To avoid pressure buildup, manufacturers have a tube that connects the top of the engine to the air intake. This is called a PCV valve, which ensures that these vapours are sucked by the intake flow and are burnt/emitted through the exhaust.
In an MPFI engine, any carbon from the oil vapours that gets deposited on the back of the valve gets dissolved by the fuel mixture itself. However, the absence of fuel in a DI engine prevents this dissolving.
So, theoretically, yes, build-up can occur on the EcoBoost engine. However, reports on the internet typically say that this is more a case of high mileage engines (e.g. 150,000 miles which is well over 2 lakh kilometres) where it becomes a problem, and more in low-load situations (e.g. pottering around town on low RPMs).
Mechanisms to avoid this that are present in cars are: - Valve overlap for exhaust scavenging - during the exhaust stroke, when the exhaust valve is opened, the intake valve is also briefly opened. Since this is a turbocharged engine, the incoming boosted air is intended to blow off any deposits on the back of the intake valve and out of the exhaust. As this is a continuous process, any deposits blown off are very light. This is a feature present in all EcoBoost engines.
- As Czarcarsm mentioned, the valves rotate to reduce deposition that prevents the valve from seating completely
Quote:
Originally Posted by Czarcarsm Please note the importance of putting fuel from reputed pumps. |
^ This.
Among recommendations to manage carbon deposits, the primary recommendations are: - Use good quality fuel, since impurities in fuel can blow-by the piston rings, into the crankcase, through the PCV and on the back of the intake valves.
- Stick to recommended oil change intervals, and don't overfill oil. Use only the recommended oils (which is WSS-M2C948-B for 5W-20, or WSS-M2C913-C for 5W-30).
- Occasional Italian tune-up :-) Highway trip? Have some fun with the EcoBoost's stellar highway performance. In the city? Once in a while rev the engine in a lower gear rather than shifting up. The higher demand on the engine results in higher boost which will help in better scavenging. If you've bought the EcoBoost, you're probably automatically doing this - no one bought the EcoBoost to drive it like a grandma.
- Confirm with your SA during each service that powertrain control module/PCM updates have been performed (if one was available). Ford sometimes tweaks the fuelling characteristics of the engine for various reasons.
- If there is significant build-up, then avoid any unapproved cleaning techniques like injecting cleaners into the intake, or brushing deposits off with a brush. All these approaches run the risk of dislodging a larger piece of deposit which might not burn up but end up going out through the exhaust; which can cause damage to the turbo. In cases of significant build-up, best to get Ford to open it up and clean the head & valves separately.
Of course, the only true test of this will be time. However, the data and informed opinion seems to indicate that it is not a major issue. |