I pretty much got all the oil and carbon buildup out of the lower, but upper plenum is to hard to get at. What is the best method for cleaning it? Is there a chemical I could use? Or would a machine shop need to "thermal" clean it?



2001 Bullitt Mustang
1995 Ford F150 302 5 speed
88 LX, down right now
87 LX, down right now

 

Try oven cleaner. I used lacquer thinner, Castrol Super Clean and oven cleaner. They all had a decent effect but the oven cleaner seemed to stay wet the longest and soaked thru the grime pretty good. Just spray plenty into the ports. The oven cleaner seemed to follow the hidden curves pretty good. Let it soak up for an hour or two then use a pressure washer or hose to blow it out. It might take a couple- three soakings but it'll come clean. Oven cleaner isn't supposed to be used on aluminum surfaces but I didn't notice any ill-effects. I think the manufacturer warns about using on aluminum because it may dull shiny trim pieces on the oven. Here that isn't important.

Randy