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Fuel System Cleaning; Seafoam question

7715 Views 19 Replies 11 Participants Last post by  pcjunkman
So my Colorado is coming up on 100,000 miles and I really want to help get its old MPG numbers or better back. I figured one of the things I'd do is clean out the fuel system. I have researched the steps and directions for this and came across this video. It seems pretty helpful with what exactly to do. I have one question about one part of it, and am wondering if y'all can help me out on this one? I do also plan on cleaning the throttle body when I do this process too!

So the guy uses Seafoam (1/3 through the Vac-line, 1/3 into the crank case, 1/3 into the tank) I get the Vac-line + Tank steps, but directly into the crank case? At about 3:30 he puts 1/3 of the bottle into the crank case (or what I thought was were you put the new oil in), and wonder if this is RIGHT TO DO? Has anybody actually done this? If this is not the correct way can Someone point me in the right direction?

Side note question; for the throttle body cleaning, do you have to replace the O-ring? I have read the tutorial on this site, but was refrerred by a friend to replace it. Any thoughts/opinions. Thanks Y'all

Link to the video
https://www.youtube.com/watch?v=V7fv-Fg1hKU
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I don't have any response for the Seafoam. The throttle body gasket can be reused. The Service Manual says to use a new gasket. Your call. I just inspect mine to see that it is clean, undamaged and is still flexible. I would suggest getting a new gasket, just in case the old one is bad. At a Dealer (part number 24100165), the price will be $5.52. FelPro, a respected aftermarket gasket maker, makes a throttle body gasket part number 61337. Advance Auto gets about $3.29 for one.
I had a predetonation ping at full throttle when I bought my truck. I bought a gallon of Lucas fuel treatment and used 5.25oz. In each tank for a while. It improved my mpg, but didn't solve the ping 100%. A friend turned me on to BG 44K. Bought a can and ran it. That 1 tank solved the ping problems. I only run Chevron with Techron now.

No problems with my fuel system now.
I have used the Seafoam in the crank case, but only in the last 500 miles before an oil change to clean up the oil passages and stuff. Never had a problem, and it says you can use it like that on the back of the can, and gives instructions on how to do it.
If you plan to add it to oil, I would also suggest not leaving it in long. Do it prior to an oil change. Maybe 500 miles as listed above, or maybe even less.

The Seafoam website actually recommends a spray seafoam for the upper intake as opposed to the liquid, for applications on vortex engines such as ours (5 cylinder engines).

I've done mine 3 times using the spray method and it works well. No problems doing it whatsoever. You insert the straw into the intake at the throttle body and spray approximately 1/2 can while the engine is running. Wait 10 minutes or so then take it for a drive. My procedure includes cleaning the throttle body. Then spraying the seafoam and finally after driving it for a few miles moderately aggressively I swing by the oil change shop for fresh oil to rid it of the contaminants that were dislodged.

It's possibility going to come down to personal preference. But the web site says that the spray in the intake distributes the chemical more evenly to all cylinders over the vacuum method. I've used the vacuum procedure on another vehicle I had. You could get two cans if you wanted the other benefits, pour some into your oil and add the rest to the gas tank. Or two fuel doses if necessary.

I have had my throttle body off 3 times, or 4 and have reused the O-Ring each time as well. Take your time removing the the clips. Especially on an older vehicle, the connectors become brittle.

Spray it with throttle body cleaner and use a clean non abrasive rag to wipe clean. Repeat as necessary.

While you are at your parts store, get a can of Mass Air Flow Cleaner too and spray your MAF Sensor.


I do not know if I have used Seafoam in the tank. To not have to purchase 2 cans of seafoam, if you elect my upper intake procedure, you could get a can of fuel treatment that is not Seafoam. I've used a Lucas product in the past. Not sure if it (or any of them) work since I try to treat them regularly. By that I mean once a year (if/when I remember). That reminds me....
I will typically run a fuel additive in the first full tank when I plan a trip so that I can actually burn it through during the extended running period as opposed to 5 mile max start/stops.
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I use it with a oil change. I substitute a quart of oil for a bottle of seafoam. but everyone is different.
If you plan to add it to oil, I would also suggest not leaving it in long. Do it prior to an oil change. Maybe 500 miles as listed above, or maybe even less.

The Seafoam website actually recommends a spray seafoam for the upper intake as opposed to the liquid, for applications on vortex engines such as ours (5 cylinder engines).

I've done mine 3 times using the spray method and it works well. No problems doing it whatsoever. You insert the straw into the intake at the throttle body and spray approximately 1/2 can while the engine is running. Wait 10 minutes or so then take it for a drive. My procedure includes cleaning the throttle body. Then spraying the seafoam and finally after driving it for a few miles moderately aggressively I swing by the oil change shop for fresh oil to rid it of the contaminants that were dislodged.

It's possibility going to come down to personal preference. But the web site says that the spray in the intake distributes the chemical more evenly to all cylinders over the vacuum method. I've used the vacuum procedure on another vehicle I had. You could get two cans if you wanted the other benefits, pour some into your oil and add the rest to the gas tank. Or two fuel doses if necessary.

I have had my throttle body off 3 times, or 4 and have reused the O-Ring each time as well. Take your time removing the the clips. Especially on an older vehicle, the connectors become brittle.

Spray it with throttle body cleaner and use a clean non abrasive rag to wipe clean. Repeat as necessary.

While you are at your parts store, get a can of Mass Air Flow Cleaner too and spray your MAF Sensor.


I do not know if I have used Seafoam in the tank. To not have to purchase 2 cans of seafoam, if you elect my upper intake procedure, you could get a can of fuel treatment that is not Seafoam. I've used a Lucas product in the past. Not sure if it (or any of them) work since I try to treat them regularly. By that I mean once a year (if/when I remember). That reminds me....
I will typically run a fuel additive in the first full tank when I plan a trip so that I can actually burn it through during the extended running period as opposed to 5 mile max start/stops.
So for the spray, would you have to take the resonator box off, and spray directly into the throttle body? Where is the proper location to spray?
Yeah Seafoam in the oil.............as part of a maintenance schedule, I put it in the oil 250 miles out from the oil change. I don't want the oil thinned out for to long.

Its amazing how quick the Seafoam will break the junk down in the oil system.
So for the spray, would you have to take the resonator box off, and spray directly into the throttle body? Where is the proper location to spray?
As following the directions on the can, this is how i did it, mind you. i have the full K&N intake system....



Also, per the can, you have to keep the RPMs up some. either have a hlper keep the rpm up, or do what i did and prop the gas pedel.
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So for the spray, would you have to take the resonator box off, and spray directly into the throttle body? Where is the proper location to spray?
As following the directions on the can, this is how i did it, mind you. i have the full K&N intake system....



Also, per the can, you have to keep the RPMs up some. either have a hlper keep the rpm up, or do what i did and prop the gas pedel.
I've done the same as this photo. The straw goes right into the throttle body, so yes the resonator has to be removed (or at least pulled away to access the throat). The can also instructs how far to insert the straw. It is like 1/8 or1/16" from the throttle plate.

I propped a 2x4 against the gas pedal and held the RPM just around 2,000. The can also suggest an RPM range. I think you want it low enough that it's not burned off to quickly. If you just allow it to idle, it will stall (flood out). You can regulate the nozzle a little too to ensure you don't flood the engine with too much spray at once.

I try to kill the engine as quickly as possible too so it doesn't stay at high RPM for long before I can get to the key. Find yourself a good spot to lay the can while the engine is running so it doesn't fall.

It's pretty simple, actually.
Very simple. why i prefer the spray vrs pouring thru a vacume line.

Also, SeaFoam recomends aganst using something like HPTuners to up the RPM. not sure with our electronic TBs, but some motors, like my old car, use a small valve on the TB to control the idle speed, and not the main throttle blade. you want the main blade open durig this.
Good reminder about not using electronic means to increase idle speed.
Awesome all, Thanks for the helpful Tips. This site is the best!
Crazy question...have any of you after doing the spray into the throttle body way, had seafoam dripping off the transmission cross member?
Not me.

Maybe you have an exhaust leak?

How much of the can did you use?

How do you know it is seafoam?
Uhh big bag of nopes

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Has anyone tried Gumout Multi System Tune Up? They are claiming it is better than Seafoam. It even looks like the Seafoam bottle
What are you trying to accomplish?

If you have already done an effective seafoam cleaning there is no need to run additional chemicals right now.
Never tried any cleaners on my truck and got it at 82,xxx miles. Almost at 100k now
Not me.

Maybe you have an exhaust leak?
How much of the can did you use?
How do you know it is seafoam?
1. I don't think so, it's not by the exhaust
2. maybe 2/3's of the can
3. It's clear and smells just like the seafoam
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