Is there a way to clean the intake system without removing? I realize if there is, caution is advised if liquid is used. Although I have cleaned out heavier deposits from behind TB, there is a lot of coating left further down. I know this has to be absorbing heat and such. I'm sure all of it is coming from the driver side valve cover vent with vaporized oil, etc. Some may have came from EGR before I removed it due to inoperation and expense of replacing.

If it were carbureted the fuel and additives would remove most, but with just air going in it would never change and only build up over time. Which is exactly what it has done. Not sure if seafoam would ever get all this and if it did, then many treatments would be necessary.

Any ideas, suggestions?

 

I too am looking for a solution... that black tar like substance can only be robbing us of milage and performance!I am considering pulling it and soaking it to remove I have about the same milage on mine as you do, The only thing holding me back is it runs so good right now, if I work on it who knows what will happen!

 

Pull the plenum and have it hot tanked, that'll get it out.

I cleaned mine out(fairley well) using brake cleaner, a drill and a rag. Then a varsol tank. I just made sure to remove everything that was attached to it. Worked nice, blew the varsol out with compressed air, and brake clearer evaporates and takes almost everything with it.

 

That's reason I don't want to pull, running too good right now. Just filled up and checked milage and 20.12 MPG, so I don't want to screw that up. Would like to get rid of some of the crud that has to be holding heat.

There has to be a gradual way to clean it without removing, not looking for instant success. I don't mean for this last sentence to be derogatory of anyones suggestions as I appreciate anyones comments and ideas, so don't take it wrong.

 

Seafoam, Use the vacuum hose that runs from the TB to the FuelEvap canister.
It atomizes the seafoam into the air and travels the whole length of the plenuum, Doing it this way one person can do it by stuff the hose in to the can and use the otherhand to turn the TB.
Sometimes hard to stall the engine but it will.

 

Didn't think of doing it there. At least that connection will coat the area behind throttle body. Wonder how many times will be needed to clean and how often? Does seafoam remove the crap and does it penetrate it enough to do any good behind the TB?

Sorry for all the questions.

 

Rebuilding my engine currently and I scrubbed with cleaner, nylon and brass brushes and rags and still couldn't get it all out. Ended up taking it to my machine shop and they are going to run it through their aluminum tank. It is tough to get out, even with the plenum and manifold out, disassembled and all that. FWIW, carb cleaner will clean the gunk, which is mostly gasoline varnish and recycled crap from the EGR, but it'll take a ton of cans of the stuff to clean the whole thing. You could use xylene or MEK, which are the basic ingredients of carb cleaner. Basically I found it was cheaper to give my machinist $15 to soak it in the hot tank and hit it with his gasket removing tools than to spend $15 at Home Depot and have to deal with a tub of xylene in my garage.

 

If it ain't broke, don't fix it!
or
You can do water injection w/ garden hose/ sprayer thru intake. Not full flow on hose just squirt it in intake while truck is running and warmed up. It'll help some. It'll also help clean carbon outta cylinders. Most of the gunk on intake is from EGR, exhaust gases, feeding back into intake. Nuthin' like diluting the intake w/ exhaust, eh?
I'm gonna try a couple things this weekend as far as cleaning intake. I just got the old engine out and need to swap everything over to new engine, so.......

 

That's what I'd do. If the truck is running fine now, don't mess with it unless you take it off and clean it completely. You might get some of it out, but I'd guess you'll loosen some and it'll eventually make it's way into someplace you don't want it. A vacuum port, injector, something.

 

I agree, don't mess with it. Stuff generated and baked on after 20 years ain't coming off with a mild seafoam treatment and it's only going to get sucked into cylinders.

I found this stuff nearly impossible to clean. My intake spend days in the parts washer, directly flow through each individual runner. Carb cleaner would cut it, but it's so nasty that you're talking about a massive amount. Going it halfway only frees stuff up to be sucked into the intake at high speed.

Want to clean it, disassemble and have it hot tanked. If you don't like this option - buy a spare (they're cheap used), get that one cleaned and swap.. It doesn't take more than a few hours at the most. Just be prepared to use new rubber (available at NAPA) for the injectors.

 

If you take it off to clean it, that would be a great time to replace the fuel filter.

 

I took my plenum off, not to hard at all. Just take pictures of everything if it is your first time, it will help a lot when putting it back together. To clean I used acetone, but what realy got it clean was soaking it in castrol super clean. And i changed fuel filter too.

 

This is the degreaser I use, the purple stuff. I think you have to be careful with it around aluminum, the back of the bottle says not to leave it exposed too long. I don't know how or if it's really harmful, but they do have that warning. So I typically don't let aluminum soak in the stuff too long, a few minutes at a time and then a good rinse. Just a FYI, because that stuff works really good. Even takes off the paint eventually. Be sure to wear rubber dish gloves when using it!

 

I did not know that... Thanks.... and it is great stuff. I am debating on degreasing my truck with it or taking it somewhere for the first time and having it steam cleaned.

 

Yeah, that purple stuff will eat anything. It likes skin too.

 

Maybe I oughtta get me some of that black tar stuff in my intake plenum if you're getting 20.12 mpg!! LOL !! I'm lucky to get 17mpg!

 

I've heard the 5speed helps on the fuel mileage- makes me kinda wish I had one.

 

Must be smoothing out the plenum by filling in the cracks and pits.

Milage before fillup by trip meter: 193.5
Gallons to fillup : 9.619