Cleaning Carbon Buildup On An 03 Silverado

[Mike437]

Hello all, new to the forums.

 

Anyway, I have a 2003 Silverado 4.8L V8. I have a tapping noise when I start the truck. My local Chevy dealership told me it's due to carbon buildup on the pistons. They want $300-400 to clean it. I've been reading online that all you need is a couple cans of GM Top Engine Cleaner, but I can't find any specific instructions on how to perform this. I was hoping someone here has done this before and could help me out. Thanks in advance.

[2500ak]

Use Seafoam (same as GM cleaner), it'll do the same thing. Comes in a metal, red and white can at most autoparts stores. Just run it slowly down through your PVC's vacuum line. There are better, more detailed instructions than that so do a search but thats the basic idea.

[wlvrn1215]

will it clean carbon out of the throttle body too? I have an 07 and the throttle body is nasty with black carbon. is this normal?

[2500ak]

No, but thats an easy fix too, you need some throttle body cleaner. It comes in an aerosol can. Just get a rag and a can of it, pull off that intake tube hose it down and go to town. Be gentle with the blade though, its more delicate on the newer drive by wire trucks.

 

The carbon gets in there from things like EGR and PVC, you know emissions devices. It does build up on the tb, but usually over a couple of years. You might pull you're PVC valve and shake it to make sure it's still working (it should rattle if it's not stuck), 07 seems too new to have carbon buildup problems but I could be wrong.

 

At any rate, seafoam and tb cleaner will effectively remove the carbon that is there. A few side notes though.

 

Don't let the engine take on excessive amounts of seafoam, it will stall it out. Some people do this to let it sit and soak in. I think a better way is to just have someone kill the engine while you're feeding it in then let it sit. Its easier on the startup afterwards, getting to much in tends to make it put up a real fight when you first fire it up.

 

Also getting too much tb cleaner down the intake will have a similar effect. Nothing dangerous, just a reluctant startup as it tires to burn it off.

 

You might as well pick up some MAF cleaner and hit your MAF while you're at it

 

Put some seafoam in the gas tank and, when you're about to change the oil in the oil to help clean that out too. I run some in there all the time but that's overkill.

 

I've used this stuff a lot with only positive effects.

[wlvrn1215]

cleaned the MAF already. Just wiped my finger in the throtttle body and it was black....guess I should spray'er down.

[Mike G]

Back in the carburetor days, we used to just use a squirt bottle and spray water over the top of the carb with the car running. The water will not combust and the dropplets ack like shot ringing around in the cylinder...

--Mike

[2500ak]

Seafoam works in a similar way, its just easier to burn off. With a spray bottle you'll probably be safe but whenever you get water in an intake it could hydro lock. unlikely though.