Air intake manifold cleanup

I’m in the process of replacing the head gaskets on my '93 Toyota 4Runner 3.0 liter v6. Upon removing the upper intake manifold a bunch of carbon fell out of it. What’s the best way of cleaning all the gunk out of the intake manifold? Thanks for your input.

Shop Vac.


Soaking with carb spray is usually pretty good for getting that stuff shiny clean, but it’s not necessary. If there were actually chunks of carbon in the intake manifold, just wait until you get those heads off, though!

Thanks for your responses, Tester and GreasyJack. I happen to have a can of carb spray left over from the Jeep Wagoneer days. I’ll give it a try. Hopefully by this afternoon I’ll have the heads off and at the machine shop!

Your manifold(s) will be off the car and you want to clean-up sealing surfaces and EGR passeges? I see many different ways to do this,what are you limits.

Sorry for the delay in replying. Seems that one of my limits is time to spend working on my project. While I’m not limited to a shoe-string budget, money is another consideration, or I’d let the boys at the Toyota dealership have a crack at it. Other than that I do have a comfortable garage on loan from a kind friend, adequate hand tools, no pneumatic tools, better than average mechanical skill, and limited ingenuity (as demonstrated by my initial question). Any ideas or advise you’ve got are welcome. Thanks.

I was thinking of a commercial parts washer,wire brushes for EGR passages,and the green nubbie discs (used on air drill)to clean sealing surfaces.

You don’t want to use those green nubbie discs on the heads while the heads are on the engine (little pieces go everywhere) some tool salesmen will sell you those discs and tell you they are safe (it won’t matter if pieces get in the oil) but I don’t trust them.

Thanks oldschool. I’ll experiment with the information you guys have sent me and post my results. Judging from the crusted up gunk on the egr valve probe and other emissions stuff it’ll take some soaking and maybe scrubbing of some kind.

If some of the deposits are hardened you might consider getting a can of aerosol gasket remover. Spray the deposits and allow it to work for a while. Most deposits will soften and can be wiped off easily or removed with very mild scraping.

If you use this stuff though a word of caution. It will make you itch like there’s no tomorrow if you get it on your skin. Spray it gently at arms’s length and preferably out of any air currents to avoid any blowback.
Best to wear glasses or goggles too; and avoid getting any scraped residue on your skin also.

If you are talking about the gunk in the passages, I used engine brite cleaner, let it sit for a couple of hours, scrubbed it with a round head toilet brush, hosed it out and then finished with some carb cleaner. Your wife won’t want the toilet brush back so buy her a new one.

Still haven’t gotten around to cleaning yet! Just got the heads off yesterday afternoon–a week later than I’d anticipated. I’ve got several different products to try, and small brass bristled brushes that I hope I don’t have to use. As for the toilet brush tip, that could lead to serious trouble. If I’m caught with it in my hand I may wind up on household janitorial duty! But I’ll keep it in mind in case I get desperate.

Be careful. I believe that some plastic intake manifolds are coated with material that is supposed to delay buildup. The wrong chemicals and scrubbing will remove it causing the problem to reoccur more quickly than it might otherwise.