How bad is this carbon buildup and what should I do about it? | Ford Explorer Forums - Serious Explorations

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How bad is this carbon buildup and what should I do about it?


Elite Ranger
Staff member
Elite Explorer
July 14, 1999
Reaction score
City, State
Omao, Kauai
Year, Model & Trim Level
'93 Ranger XLT 4X4
I had my mechanic neighbor replace valve cover gaskets and plenum gasket today while he was replacing a freeze plug.
Here’s how it looked, intake was the same, of course.
It’s already put together again to get it out of his driveway.
At this point, what should I do, seafoam through the brake booster tube?


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I'd leave it alone and change the PCV valve
it won't hurt or help on the seafoam imo

I don’t think it’s that bad. I’d Seafoam it and take it for a higher rpm drive, like on the highway without OD.

Huh. I haven’t seen inside enough intakes to know what’s normal and not, I figured this was pretty bad.
I did very recently change the PCV, and it does not get much highway time. It’s a small island, I’ve never used 5th gear because there’s only a few stretches that you even can get up to 50-55mph.
Maybe it’s this way because the engine never gets hot hot?

That actually looks normal. Seafoam, Marvel Mystery oil or acetone will break up the carbon.

Absolutely normal / better than normal. I've been able to scrape it out with my fingers before I've seen it that thick. Dirty air filter and pcv are the biggest cause of the build-up

Mine was that bad when I took off my intake plenum. I sprayed the **** out of it with carb cleaner, then turned over the engine a few times with the spark plugs out.