i posted this tip on someone elses thread yesterday. Is it only under load? if so you might have some carbon build up on the intake valve. Sea Foam works good, but for the price it's better to use this method.

If you suspect Valve build-up get yourself a gallon of regular windshield washer fluid (methanol) and with your truck warmed up, take the air cleaner off the throttle body. With the truck running, slowly pour the washer fluid in the intake with the RPM's between 2000-2500. after the gallon is gone let the truck run for about another 5 minutes to burn off all the methanol. take it for a drive and see if it still does it.

The problem with valve build up in electronic controled engines is that if the compression goes up you PCM changes the timing. if the timing gets too bad you get spark knock and your truck will feel a little less proud of itself in the throttle. clean the valves, compression goes back down to where it should be and timing corrects itself. problem solved.

 

I didn't know that windshield washer fluid was just methanol... the blue stuff?

If that's the case, I could use it instead of buying Denatured alcohol for other applications... which is mostly ethanol but about 10 percent methanol.. they are really similar alcohols as far as anything but drinking it goes... =)

 

yup just plain washer fluid. read the bottle. I couldn't believe it either until i saw a guy that runs methanol injected stuff pouring it in his gas tank. that's when i relized it. he said it burns pretty clean. That's when i decided to give it a try on a go cart i had to see if i could clean the valves. Man did it work so i do that from now on instead of taking off the heads and having them cleaned. About 20 mins worth of work and your valves are good to go.

 

Wait... so you dump washer fluid directly into the air intake while keeping it at 2000-2500 rpms? I thought the only thing that was supposed to go into the intake was air. Has anyone else tried this with success?

 

The thing about this is that you're not flooding the intake so that it's not getting any air. You pour slowly, like you're filling your radiator with antifreeze. It boils before it can bog it down. And since it's methanol it won't hurt anything. you can do the same with just water, however it doesn't work as good because it boils too fast and cools the valve down faster so it doesn't get as much carbon off as washer fluid. I promise, try it and you'll be amazed. I've done this on a couple of cars now that I know how well it works.

 

Wait... Water seems a bit "far fetched"

Your gonna have to back that one up with something scientific =)

 

You are not pouring enough water to drown out the engine. That's also why you need the RPM's up around 2000-2500 so it's sucking in quite a bit of air. It's gonna boil the water off before it'll even start to put out the spark. think of it as if you were pissing into the intake. That's about how fast you want to pour into the intake. make sense? Whenever you crack a head gasket and you're burning water the car still runs, just not great. I'm telling you It'll work. It's not for that long and not that much water. I'm talking like 1 gallon of water in 20mins, that's pretty slow. If you aren't willing to try then just take the head off and have your valves cleaned that way. that's atleast 3 hours worth of work compaired to 20 mins and not getting greasy.

 

it is a interesting idea.. that's true, coolant doesn't kill em. If im gonna do it, i would use the methanol as you said

 

Water works, less is more in this instance. It does defy common sense, but not scientific fact.

 

I guess water still works, it did 50 years ago. pour it slowly, it will turn to vapor and soften carbon up.