How To: Seamfoam Treament (3Rd Gens V6)

[MuddyWater]

Hello! Based on multiple reads supporting positive results from the SeaFoam treatment and since there was not a clear and dedicated simple how-to thread for 3rd gen V6 4Runners. I've decided to put one out there specifically for us 3.4 V6, 3rd generation, 4Runner owners. I've gathered information from other threads as well as the manufacturer. There are 3 points of engine treatment where it is recommended to see results. It is recommended that 1/3 of the bottle be used for each of the 3 points of treatment.

1) PCV Hose
2) Crank Case (Oil)
3) Gas Tank

I will go through the PCV treatment first which seems to be the most confusing to some, especially the non-mechanically inclined. Although it is specified to use the break booster hose, on our trucks this will only provide treatment to one cylinder. By using the hose specified in the picture you will increase the likely hood of the treatment reaching all cylinders.

Part I: Treatment via PCV Hose - To clean deposits from the tops of cylinders and the backs of intake valves

Step 1: On V6 3rd Gens you want to use the vacuum hose specified in my picture below. Also take note of the red arrow as this is the entry point where you will make the disconnection and will be using this as the point of entry for SeaFoam to the intake system. Once you have given some thought as to how you will be supplying SeaFoam to this hose (some have disconnected the existing hose to utilize a temporary longer one for ease of application). I purchased the spray bottle (14oz) so I will be either guessing 4.6oz (x3) or spraying it into a clear container for a more accurate measurement. The small plastic bottle that I am referring to can be purchased at a Harbor Freight or other local hardware store.

Step 2: Once you are ready to proceed with the treatment. Warm up the truck and while the truck is still idling, disconnect the PCV hose from the point indicated in the picture. You will immediately hear the vacuum noise that is created by the suction which is normal. At this point, you will want to dip the hose into the container holding the SeaFoam and allow it to vacuum all of the SeaFoam (1/3 of bottle) OR pour it into the hose (SLOWLY). I say slowly because of reading that there is a risk of hydrolock if it is poured too quickly. During the treatment the truck will start to idle rough. You may need an assistant to maintain idle as you are pouring/spraying/vacuuming the SeaFoam into the PCV hose.

Step 3: After your have completed adding 1/3 of the SeaFoam. Shut down and reconnect the vacuum hose to the engine and allow it to sit. The manufacturer specifies allowing it to sit for 5 minutes but I will allow it to sit for 10 for good measure to allow the SeaFoam ample time to loosen dirty deposits.


Final Step 4: After 5-10 minutes. Fire up the engine and allow it to run with periodic revs to clean out the combustion deposits. At first, it will smoke a little but it will eventually become a significant amount of white smoke. This is normal since it means that the treatment is doing its job in getting rid of the dirty deposits. This will continue for a while (5-10mins) and eventually dwindle. Once the amount of smoke has dropped you may take it for a ride to see if you personally notice any improvement. Some have even driven aggressively (but legally, 2-5miles) during the smoke out period, but that is up to you if you want to the whole neighborhood to see how environmentally conscious you are. I live in California so...

NOTE: As mentioned this treatment WILL result in a considerable amount of smoke being exhausted and if your neighbors are a little sensitive about the environment or want to avoid them calling the local FD. You may want to consider doing it at night. More importantly, Tom P. as stated in his comment below, has brought up a good point. Consider doing this part of the treatment prior to a tune-up or simply change the spark plugs and O2 sensor after treatment. The reason is that after treatment, there will be a sudden increase of carbon deposits which will increase the possibility of fouled spark plugs and clogging to the O2 sensor.

 

[MuddyWater]

Part II: Treatment via Crank Case (Engine Oil) To clean built-up oil residues and contamination from the crank case

As noted above, this treatment will clean residue and contamination from the crank case. NOTE: This treatment is recommended to be performed just prior to your next oil change (100 miles). You don't want the loosened gunk resulting from treatment to be lingering in your engine longer than than a 100miles.

The treatment process is pretty simple and straight forward, but I will again make it as easy for someone who has never even looked under their hood.

Step 1: Locate engine oil cap (See picture)

Step 2: It is recommended adding 1.5oz of SeaFoam for every 1 quart of oil. However in my case I will be adding 4.6oz approximate (1/3 of bottle).

Final Step 3: Drive vehicle as normal for approximately 100 miles. After which time perform your scheduled engine oil and engine oil filter change.

NOTE: According to SeaFoam. The treatment will slowly re-liquefy residues and suspend contaminants for easy removal. Monitor oil for color and clarity and change oil and replace filter when oil looks dirty.

 

[MuddyWater]

Part III: Treatment via Gas Tank - To control moisture buildup

This is the easiest of the 3 treatments to perform. By now you should only have 1/3 of the SeaFoam treatment remaining.

Step 1: Simply remove gas cap and pour in the remaining Seafoam solution. SeaFoam recommends 1oz per every 1 gallon of gas.

NOTE: In my experience in monitoring fuel consumption. I approximately had 5 gallons of gas remaining when the low fuel light warning appears. That would be the best time to add the remaining SeaFoam.

Final Step 2: Simply drive truck as normal and your done.

Please take note of the comments made on this thread as they may add to the effectiveness of this treatment​

.

You have now completed your SeaFoam treatment on your 3Rd Gen 4Runner.​

 

[Tom P.]

From what I've read, a person might want to do this before a tune up and/or 02 sensor change, since it may foul things up. (Do I have that right?)

Anyway... Clearest write up yet. Good job!

 

[Singtoe]

Get write up but I have one suggestion.

I would flood out the engine with Seafoam so that it stalls out. Do not race the engine during the flooding process to prevent damage from hydro locking. This will cause the carbon deposits on the pistons and the combustion chamber to be throughly saturated with Seafoam solvent. I then would let it soak over night to let the solvents break down the carbon deposits. The excess Seafoam will leak past the rings over night and should start up with out hydro locking.

 

[MuddyWater]

Thanks fellas... and that's the type comments that will be appreciated by other members as well as myself. The deposits will increase the possibility of clogging the O2 sensor and fouling the spark plugs after treatment. I will note it and leave it up to the individual to perform the additional step(s). As you mentioned the purpose was to provide a clear and simple write-up on this process (especially on "Part I") for even the most novice of truck owners. Thanks Again!

 

[WArunner7710]

What kind of harm can come from over seafoam-ing? Say I were to make a significantly higher fuel-to-foam ratio for the last 50-100 miles out or my tank, or dump a whole bottle into the block??? Would this wreak havoc on my power plant???

Great write up by the way. There are a million out there but I feel like this one should be sticky somewhere. .......:nicethread:

 

[BrianSD_42]

What kind of harm can come from over seafoam-ing? Say I were to make a significantly higher fuel-to-foam ratio for the last 50-100 miles out or my tank, or dump a whole bottle into the block??? Would this wreak havoc on my power plant???

the question I have in response to your question is what is the current status of your engine? You never know, you might not even need to do the seafoam.


Have you changed your spark plugs, plug-wires, O2 sensor(s), air filter, fuel filter yet?

I would do all of that first. I've never SeaFoamed and I'm at 213,000

 

[WArunner7710]

the question I have in response to your question is what is the current status of your engine? You never know, you might not even need to do the seafoam.


Have you changed your spark plugs, plug-wires, O2 sensor(s), air filter, fuel filter yet?

I would do all of that first. I've never SeaFoamed and I'm at 213,000

I actually just purchased my first t4r, put a lot of love into an 02 Tacoma then sold it like a fool... Few vehicles later I decided it was yota time again and went with the full body this time. Picked one up with 190k on it. She runs really well, but super sluggish and only pulls 14mpg. I just did plugs, wires, o2 sensor, all fluids, greased the drive train, cleaned out the TB and MAF sensor.... Still only pulling 14 mph.... Im looking into anything that helps it not feel like driving a bus....

 

[BrianSD_42]

but super sluggish and only pulls 14mpg. I just did plugs, wires, o2 sensor, all fluids, greased the drive train, cleaned out the TB and MAF sensor.... Still only pulling 14 mph.... Im looking into anything that helps it not feel like driving a bus....

That sucks man ... I haven't seafoamed my truck or cleaned my MAF like some of these guys and mine seems pretty peppy.

BUT ... I have K&N CAI, high flow exhaust, two new JE heads and a sludge free engine. I usually get between 16 and 20 depending on how I drive.

Do you know that the US Government has re-rated the V6 3rd gen 4Runner as having 15-18 MPG? This is down from 17-21 (I think).

I don't know how some of these guys are getting 22 MPG but my gut is that those trucks have super-chargers and some fuzzy MPG math as well. The fact is that 15-16 is normal.

Good luck though.

 

[thebrandon]

I like the write up. I've been a fan of SeaFoam for a while now. Does it help? I have no idea to be honest. I just know the first time I used it, I added it to the fuel ONLY. I had puffs of black smoke come out the exhaust when I would rev the motor. I thought it was a hoax and just because I added the stuff to the gas. Well I added some more a few tanks of gas later, and no black smoke. So I suppose it really does get some of the gunk out of there.

My only question regarding adding it to the fuel...anywhere on the bottle does it recommend where your fuel level should be at when introducing SeaFoam to the fuel? I want to say I've heard to do this on a full tank for "best" results. Or does it only say to add 1oz per gallon?

 

[Singtoe]

What kind of harm can come from over seafoam-ing? Say I were to make a significantly higher fuel-to-foam ratio for the last 50-100 miles out or my tank, or dump a whole bottle into the block??? Would this wreak havoc on my power plant???

Great write up by the way. There are a million out there but I feel like this one should be sticky somewhere. .......:nicethread:

The only harm that can happen from over seafoaming is to your wallet. You will get to point where no further cleaning can be done.

the question I have in response to your question is what is the current status of your engine? You never know, you might not even need to do the seafoam.


Have you changed your spark plugs, plug-wires, O2 sensor(s), air filter, fuel filter yet?

I would do all of that first. I've never SeaFoamed and I'm at 213,000

When to Seafoam.

1 When you have a dirty combustion chamber. This would be a build up of carbon on the top of the piston, the bottom of the cylinder head and the sealing surfaces of the rings.

The easiest way to check for this is to drive with regular unleaded gas, If you hear a spark knock when under load (pulling trailer, going up hill) and it goes away using premium unleaded gas, you have a dirty combustion chamber.

Cleaning the chamber and rings will improve motor performance and fuel milage as it is working at its best effiantcy.

2 When your engine internals are sludgy. Poor preventative maintenance is usually the cause of this.

To check for this, use a flash light and visually look in the oil fill cap to see inside the motor. It should be bright and aluminum looking. If you see it tarnished or has a build up of dark sludge, time to seafoam. Now there is a sheet metal baffle that is in the oil fill area. This will always be sludgy looking (most of the time) and should not be of concern.

It will take many applications of seafoam over the course of many oil changes to get the motor clean again if it was heavily sludged up.

3 Dirty fuel system. I have no experience with this so follow the directions on the can if you want too.

 

[jkoni426]

great write-up!

I buy 2 16 oz cans of seafoam though... dump one whole can in the gas tank before a fill up, half of the second can through the pcv hose, and the other half in the oil. Going by the company's recommendations, you don't get enough into the system using only 1 can.

1.5 oz per quart of oil (5.5 quarts) = 8.25 oz (about half a can)
1 oz per gallon of gas (18.5 gallons) = whole 16 oz can
1/3 to 1/2 can through the pcv hose

total = 2 16 oz cans

I've already done the oil and gas since I bought my truck, and have a half can left to do the intake soon.

 

[Foo-Fighter69]

Sticky? I did this yesterday. I spent a lot of time trying to find a write up ending up finding on yotatec.

 

[thor999]

Just replaced my O2 sensor, what are the TRUE chances of fouling it by seafoaming? Don't really want to spend that $$$ again...

 

[Steve240]

^ I'm also interested by that I just put new plugs in.

Would you guys consider seafoam preventive maintenance, or should only be used if your having issues?

 

[JWaldz]

Great little write-up.. Rep power for ya!

 

[MuddyWater]

What kind of harm can come from over seafoam-ing? Say I were to make a significantly higher fuel-to-foam ratio for the last 50-100 miles out or my tank, or dump a whole bottle into the block??? Would this wreak havoc on my power plant???

Great write up by the way. There are a million out there but I feel like this one should be sticky somewhere. .......:nicethread:

Here's the response received from SeaFoam from their ASE Certified, Technical Sales Director, as follows:

"Sea Foam is a petroleum based product and contains no harsh chemical additives. Sea Foam is used daily in injection cleaning equipment and used at a 50/50 ratio with fuel to clean injectors on the car. Sea Foam is safe at any ration and will not harm your engine of fuel system."

 

[WArunner7710]

Here's the response received from SeaFoam from their ASE Certified, Technical Sales Director, as follows:

"Sea Foam is a petroleum based product and contains no harsh chemical additives. Sea Foam is used daily in injection cleaning equipment and used at a 50/50 ratio with fuel to clean injectors on the car. Sea Foam is safe at any ration and will not harm your engine of fuel system."

Perfect, that's what I needed! Time for the super seafoam treatment!

 

[mattleegee]

Thanks for the write up, i did this on my Taco a few years back and used the brake booster (1/3) and gas tank (2/3)

Just did one bottle in the new 4runner (135k) i put probably 2/5 into motor, 2/5 into pcv hose and the last 1/5 into gas tank
Will dump bottle two completely into gas tank when its time

Too bad its going to take like 3 weeks to run out a full tank of gas, maybe have to do a road trip to run it through really quick