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Seafoam

2002AVA

Full Member
Joined
Jan 14, 2005
Messages
3,152
Location
Coarsegold, ca
I know this has been talked about before, but I could not find the thread. I just seafoamed my Av after 30k miles. i used about 12Oz's of Seafoam. My Av was not happy having it forced into her manifold. She smoked and idled funny while i was doing this. Kinda like forsing cough medicine down your kids throat. Afterwards she smoked for about 5 minutes, but dam she runs so much better. I figured the more she smoked the more crap she was bunring off. She is not smoking anymore and has a lot more get up an go. I really need to remember to do this more often.
If you have not done this I highly recommend it. Just disconnect the Vacuuming tube that connects to the Master brake cylinder. Use a funnel that fits in the hose. Keep the truck running, it will have a hard time keeping idle, so pour the Seafoam in very slowly. Don't do to much at once or it will stall the engine. Smoke will start coming out of the tailpipe immediately, don't worry it is just the carbon on the valves burning off. After you are done, just plug the hose back into its home and you are done. I recommend driving around a little to get the rest of the carbon smoke out.

This is one of those things you would do after cleaning your MAF and filter.

Hope this is helpful.
 
I have been thinking of doing this lately

I used this stuff to clean a set of used injectors, on the bench with a homemade machine. went from 11- mpg to 14+ @170k

The only fuel product I believe in anymore!
 
When I do the cleaning I dump the remainder 4 ounces plus another can into a full tank. It is a nice a thourough cleaning for the intake system. The MPG also goes up. I have been using Seafoam since I bought the Av in 04. I dump it in the tank all the time, I try to do the Intake every couple oil changes but have not been keeping up on it due to the weather. I have found working on a truck in freezing weather is not that fun.
 
" Just disconnect the Vacuuming tube that connects to the Master brake cylinder. "

To the brake cylinder? I might have to go do this tomorrow, my dealer is going to run something through for a fuel rail flush but if that doesn't work I'll handle it myself. Rough idle now and then (sounds like a misfire) and misses on hard acceleration. They checked and it isn't any one particular plug or injector, seems to bounce around the injectors so they think this flush will fix it.

I ran a can of Seafoam through the tank about 6 months ago and it was a little better for awhile but now it's back, is it the same bottle?
 
Yep it is the same bottle. Are you getting any codes or engine lights? Seafoam does wonders for your intake. It takes about 2 minutes and the Seaform is about 8 bucks depending where you are.
 
Before you change the oil. I will try to get a pic today. It is the big black vacuum hose hooked to the side by the brake booster.
 
My mechanic friend told me about this 5 years ago. He did it on my 85 caprice back in the day and it did wonders for the whip! (I miss that car)

I'm not sure what he used (seafoam or what) but he did this exact same thing

 
I use Seafoam in my 02 Avy about every 20k and it works great, however I read on the Seafoam website you could put it in your oil. BAD idea it is very corrosive like tranny fluid and breaks down oil to almost a water type consistency. Also if your truck runs rough after the Seafoam treatment it could be a fouled plug or O2 sensor due to the carbon burn off. I had to change the plugs after the first go round due to fouling. If you do it often enough you engine will be squeaky clean and purr like a kitten.
 
That is why I recommend changing the oil after treatment. All that carbon burn off and seafoam can get into the oil. I would never put it in the oil, it just does not seem smart to me. It does however do wonders for the intake. It did foul out my Iridium plugs when I did it with them. The Bosch Platinum's are holding up a lot better, and are cheaper. I highly recommend this treatment about every 15k or so.
 
Well back from the stealership, it made the missing better but didn't fix it completely. I still think there's a problem. And... during the test drive I stopped to fill the tank. I looked down and my rear driver wheel was smoking. At first I thought it was the brake pad but on closer examination I noticed something splattered around the circumference of the wheel well. Lost a rear axle seal, so my $80 fuel  flush (which actually turned out to be $140) turned into a $400 Av appreciation day. BTW, I didn't let the stealership do the rear seals, I'm fed up with them.
 
Here are a couple pics for you. Mine is an 02, so the the Master Cylinder is not as big as the newer ones.
 

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Actually the right way is put it in fast (while engine is hot) and kill the engine and let it soak for about 10 min then restart. (it wont start right up you will have to crank it a little) 

when i say put it in fast i mean pour it in fast enough to make the engine stall, then the seafoam will coat the cylinders and valves, leave the engine off and let it soak for 10 minutes then take it out and romp on it
 
If I want to add to both the intake and fuel should I add 1 full can to each or split up one can? I don't want to go overboard, but I would like to clean out both systems.

Thanks!
 
I would use 12 ounces in the intake, dump the remainder 4 ounces plus another can in the tank. 1 can only works with up to 25 gallons so the extra 4 ounces from the 1st helps.

I have never heard of killing the engine and letting it sit. I had always heard to do it slowly and let it run thru the system. The only thing i don't think would work about soaking is that the engine sits at a slope. So most of the seafoam would soak into the rear cylinders.
With the engine running it gets sucked into everything and burned out the exhaust.
 
Would it be just as good to just let the vacuum suck in the seafoam or should it really be pured down the line? It seems like it would be easier to just pour the seafoam in a bowl and let the hose suck it up.
 
I have a little funnel that fits inside the hose tight. I use that and just pour a little at a time and pour just enough so the engine doesn't die. There is no chart for the amount just play it by ear. Your engine is going to sound like it is dying. The idle is going to jump all around while you are doing this. Your exhaust is going to be pouring out a lot of smoke. My was smoking the next day, but I did not go and drive my Av hard after I did it. I had to drive 30 miles to town the next day and that is when I blew it out. I just romped on it from a standing start and held the accelerator down until I hit 90MPH. I did this as many times as I could.
 
Shanes 02 Avalanche said:
Here are a couple pics for you. Mine is an 02, so the the Master Cylinder is not as big as the newer ones.

Mine does not have that hose? Do the 2004's not use vacuum boosters? Mine looks like it may be hydraulic. So is going through the PCV valve the next best bet?
 
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