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Seafoam in Gas Tank

14K views 80 replies 14 participants last post by  Mikey319 
#1 ·
Hi again, I've been reading about Seafoam and I can't find anything conclusive about JUST putting it in the gas tank only. I just filled it with premium (always 92 or 93 octane) and I used Lucas deep fuel clean about 3,000 miles ago, but I don't feel or see any difference. I watched YouTube videos and saw that it did little to nothing and then watched Seafoam videos and saw it worked very well. I want to use the Seafoam on my car, But I don't know if I need to change the oil after the tank of gas or not. I don't want to change the oil I just want it in the gas tank and that's it. Is that possible?


When it's time for my oil change I will be using it in there too but that's another 1,400 miles so I don't want to put it in until the day of, and then drive it a little with the Seafoam in and then get an oil change.
 
#2 ·
I've never been a fan of Seafoam and I'm sure I would not put it in my oil. If you are running a VW approved full synthetic oil like Mobil 1 or Castrol 0w-40 or 5w-40 that's all you need.

For gas treatments Chevron Techron is the go to additive.

Now what you should do is clean the throttle body and intake. Assuming you haven't done this already. It's an easy DIY project.

http://www.passatworld.com/forums/b5-information-base/461705-v6-throttle-body-intake-cleaning-w-o-removing-3m-diy.html#post3833281
 
#3 · (Edited)
the guy did a video with techron as well and it also did little to nothing.

I would never trust myself to do that. Seems like a great write up, but I just don't trust myself on taking my car apart.

Not sure what oil is being used. I had to add a quart myself though because it was low. I put in Mobil 1 0w-40

Maybe I'll see if my step dad will be willing to help me. I doubt it though.
 
#20 ·
I have heard great thing about redline fuel system cleaner. It has more P.E.A than most fuel system cleaners on the market today. It's supposed to be some of the best fuel system cleaner on the market from what I hear. As for oil addatives Marvel Mystery Oil is great.
 
#25 ·
Mikey, too much money burning your pockets? Your car is fine, don't think about replacing the transmission. It's normal to upshift when there is no load on the engine.
IMO the code you had P0421 is due to a failing cat. However it will not affect driveability AT ALL, and Seafoam will not help with anything (well, it would help psychologically). I would check with the dealer about the software upgrade for the cats. Some V6 people report using spacers... The "fix" is probably a new cat.
 
#28 ·
I think if my step dad helps me clean the throttle body, we get it aligned again, get a transmission flush, and the re-flash, it will be perfect. I do need shocks/struts in the front left tire it clacks over like every bump

is it supposed to make a lot of noise inside the cabin? Like all of the electronics and such? It's really loud with ticking and clicking and such. I recorded it if you would like me to post it.
 
#31 ·
I would wait, it's not going to fix your P0421 code. Get your codes pulled again today as you had planned. Write down all the code #s they tell you and then post them here. Codes will allow people to give you more accurate advice.

As gigi said call a dealer with your VIN # have have them check to see if your car had the update done for the Cat faults. I don't remember the years involved, but there was a software issue that was causing CAt faults and the update fixes it. The update should be free.
 
#35 ·
I've seen it suggested elsewhere on this forum that if you're having issues with fuel system/missing to use a large bottle of Techron on a half-tank of fuel. I just did that and it got rid of my random misfires. Did you ever get your flex pipes fixed? I think I remember that you posted that they were leaking. That caused all sorts of codes on my car.
 
#37 ·
that was the second thing I replaced in my car :/ 560 dollars later. It's just not driving right and idk what to do. I'm setting up an appointment with a mechanic shop near me next week. I showed her what my car was doing with reverse and drive and she's like yeah you probably will need a trans flush. Which k figured because it hadn't had anything ever done to it transmission wise. They said drop it off in the morning one day and we will need it to be here for the whole day. Which is understandable if they are checking my trans. It needs to be cooled down 100% in order to get a reading, correct?
 
#39 ·
I called yet another dealer. They said. I open recalls or anything and that it would be 115 dollars to diagnose it (richer part of New Jersey) so I said I'll just see how it goes thank you. I just don't get why I keep getting this code (P0421) since day one with this car. I don't get why I keep getting a CEL. It's driving me crazy. I just want my car to run perfectly fine. ://
 
#40 ·
I just don't get why I keep getting this code (P0421) since day one with this car. I don't get why I keep getting a CEL. It's driving me crazy. I just want my car to run perfectly fine. ://
Sure you do; we explained the possibilities to you. The car, for some reason, thinks the CAT isn't working right, and the light is telling you that. Good news is, the car will probably run just fine with a P0421 showing. It just won't pass inspection, if applicable.
 
#42 ·
I've put a bottle of Techron in the tank every oil change for my cars for 20 years. The Passat had it gauge issue while the daughter had it at college and she used cheap gas that probably left deposits. I also use Chevron gas pretty regular because it has Techron additives in it.
 
#44 ·
And I think it is burning oil :( I added a quart less than a month ago? It's now under the fill line again. It's the dipper stick with the orange bottom, then the metal with dots on it in the middle, followed by another orange thing. Its not even covering the entire bottom orange part. I filled it to the middle of both orange pieces.
 
#45 ·
Mikey, Mikey, Relax! All passats use some oil, either burning it or leaking or both. I would suspect your valve cover gaskets and cam caps are leaking, but it's all normal wear maintenance items on a passat.
You cannot solve everything little thing RIGHT NOW!. The car is fine be happy drive it, do regular maintenance and work on the issues one at a time. Best thing I think you could do is sign up for a basic mechanics/car maintenance course at a local community college. It will give you the experience and confidence to do some of work on your car (and future cars as you have a few more coming your way). It's obvious you care about the car and want to keep it in top condition. Not that you should stop posting or asking questions. Keep doing that it's how we all learn.

As for the gas, if Costco is close use them. They are now a Top Tier gas dealer. Wawa and Quick Check are not. Top Tier gas stations have about 10 times the cleaning additives that non Top Tier stations do. Non TT stations only have the Federal minimum requirements. You can google TT gas for more info.
 
#46 ·
My valve covers are possibly leaking. But it might just be coming out of my oil lid. I'll start doing repairs one by one like you said. I'll do major stuff first then to the little stuff. It's going to be diagnosed sometime next week I believe. I hope it's nothing major :(

I don't have time or money to take a class like that. I still wouldn't want to work on my car lol I wouldn't trust myself.
 
#49 · (Edited)
Poor man's throttle body alignment.
Engine temp must be between 5c - 95c so best to do when engine is cold.
Disconnect the battery's negative terminal
Brake lights on for 1-2 minutes.
Reconnect the battery.
Turn the ignition to On
Do Not start the car
Do not put your foot on the gas pedal
Wait 1-2 minutes with the ignition On
Turn ignition off
Start car as normal.



Sent from AutoGuide.com Free App
 
#50 ·
Poor man's throttle body alignment.
Engine temp must be between 5c - 95c so best to do when engine is cold.
Disconnect the battery brake lights on for 1-2 minutes.
Reconnect the battery.
Turn the ignition to On
Do Not start the car
Do not put your foot on the gas pedal
Wait 1-2 minutes with the ignition On
Turn ignition off
Start car as normal.



Sent from AutoGuide.com Free App
thats the negative, correct?
 
#55 ·
There is no changeable power steering fluid filter on your car. The leaking is more than likely from the connections at the cooling loop mounted to the front of the radiator. Very Easy diy for you o do. All you do is replace the two clamps with fuel line type clamps. A couple of bucks at any auto parts store. First you need to check the power steering fluid level. Low fluid will cause the pump to grown and will destroy the pump if left unresolved. There are also diy's on flushing the power steering fluid if you feel up to it. Also pretty darn easy. Or have the shop do a power steering fluid flush for you. Always remember to use the correct VW approved fluids.

The Brake light = Putting your foot on the brake pedal while the battery was disconnected to drain power from the system. No, big deal all seems to have worked well.!

Mikey! Your first DIY!! Throttle Body Alignment a success! :thumbup:
 
#56 ·
wait. Mixed it up. It's the pressure nose near the left gasket under the left plastic cover. When I got the car it was under the minimum line for power steering. I have fluid directly from VW parts department :)

Oh! Well I know for next time if I need to do it again :)

YAY!!! :D I am so happy right now!!! I cannot believe how much more power I got and almost zero hesitation! It also seems to be downshifting better as well I don't get as much of a giant clunk when I press pass the gear ignorer thingy and then have my foot off the petal.
 
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