cbrenn71

Like the title says, i'm installing a UPR CSS can can into my 3.5 eco. It currently has slight stuttering at start up. The truck has 60k miles on it. I'm assuming i have some carbon build up/coking on the intake valves.

With the catch can installed, will the carbon eventually break down and diminish due to heat cycles over time, or do i need to remove the intake manifold and do some cleaning on the valves??

Tothemax

No the carbon will not go away over time. The last I had heard, ford had no approved method for cleaning the valves.

MGD

^^^ Apart from any alleged buildup ( borescope to check before disassembling anything), you ARE overdue fer a plug and boot change:


MGD

cbrenn71

CAC and plugs were replaced ~6,000 miles ago

Chad Walker

Use Chevron with Techron fuel system cleaner at least a couple of times in a row. See if that helps.

Tothemax

Pretty much just a waste of money but you can use it I'f you wish.

Chad Walker

It currently is the only thing recommended by a somewhat legitimate source (fordtechmaculoco) so it's worth a shot.

Tothemax

If you run quality fuel you don't need to waste money on the additives.

HPDMotor

The problem with direct injected engines is the fuel is sprayed directly into the combustion chamber like a diesel. Without the fuel coming in through the intake tract, either via fuel injection or carb, the oil mist that is sucked up via PCV system gets baked onto the stem area of the valve. The issue has been documented since direct injection really hit the road. Fuel additives and all the conventional cleanings don't touch the backside of the valves to clean them.

Neil

mrv99

What BMW has been doing to address this issue is walnut shell blasting. Rotating the valves to shut them and blast away.