Does cleaning out the intake manifold have any measurable effect?

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Changed the spark plugs and wires on my 99 Taurus with the 24V Duratec V6 and you have to take off the upper manifold for access. It only has 62,000 miles so it wasn't too dirty, but I cleaned the lower manifold.

Before,

[Linked Image from fototime.com]


After,

[Linked Image from fototime.com]


Does this make a noticeable difference in performance? The upper intake is similarly dirty. Should I clean that too?
 
No, cleaning it makes no difference except where the deposits cause restrictions. I suppose it could be argued that thick deposits make a small restriction anywhere for a tiny % benefit. However it may reduce the rate at which any local sensors get fouled, and of course help to make a better seal where gaskets are involved, and reduce the chance that any later (especially cleaning solvent sprayed in) dislodged chunks of deposits could make their way to valves and cylinders.

If having it apart makes a PCV valve easier to access, now might be a good time to replace that too.

As far as cleaning the upper intake, sure why not? I just wouldn't do much more than a spray cleaner, no elbow grease and scrubbing unless there's thick deposits stuck in place.
 
Last edited:
Originally Posted by atikovi
OK, at least it looks pretty.


Looks a lot better. Brake cleaner?
 
Without all that crud absorbing some of your fuel mixture, you might find a hint more reponsiveness if anything. Regardless - it needed to be cleaned since it was all apart anyhow.
 
I was told by someone once that a lot of carbon there could lean things out. I am on the fence with that. Myself, I would clean it up since it is staring me in the face and could prevent those throttle plates from sticking someday.
 
I think it is worth cleaning. You would need an engine dyno to see the difference, I dont even think a chassis dyno would be able to tell. That 3.0L duratec must have been a costly as none in my area have the badge. I remeber the mercury sable I drove had that engine and it was very smooth and quiet compared to the vuclan 3.0L push rod engine.
 
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