Seafoam and no smoke

[oblivion_twister]

if you want to do the job correctly, take the vacuum hose off at your brake booster, hold your thumb over it, have someone else start and keep the engine running while you slowly pour about a third of the can into the vacuum hose, not letting it die. Do this with it warmed up already then let it set for an hour. Go out to fire it up and your neighbors will be caling the fire department. Will be hard to start and will run rough initially. Just keep running it and revving it and it will smooth out. After about 15 mins most of the smoke should be out

[4jeepers]

I did the same with my 88 XJ. I poured a whole can into the throttle body at 1400 RPM and saw no smoke at all!

[Fidishund]

seafome New to me will have to try it

[muddeprived]

Remember guys, seafoam doesn't guarantee a smoke show. If it's not dirty, it's not dirty.

[4.3L XJ]

Here is another tip. If you dump enough Sea Foam in the intake to get white smoke, that is not carbon you see. It is improperly consumed Sea Foam. At that level, it can take out your O2 sensor. I have seen this happen twice on another forum. If all you want to do is get rid of carbon in the combustion chamber, THEN JUST DUMP IT IN THE GAS TANK AND DRIVE. Yes I am shouting. It is that simple, no drama and it works that way. That is the way the smog guys here in CA do it. I have verified that it works that way with a tear down immediately afterwards.

[stamp]

to clean up carbon in you combustion chamber pop a headgasket ... it works

[greenneck]

Ive seen Seafoam mentioned many times. What exactly is it and how/when should I use it?

[4.3L XJ]

Sea Foam is a product we see a lot here in CA that is designed to clean out your engine. You can put it in your crank case right before an oil change and clean out some sludge. You can pour it in your gas tank and it will take the carbon out of your combustion chamber. It will also clean up your intake runners by pouring it in the intake while running at about 2000 rpm. But if you do this, be prepared to change out your O2 sensor afterwards. Most people don't need to clean intake runners. The most common way to use it is to pour it in the gas tank and just run the motor. Take it for a drive or something. It will help your gas milage and power a little and if your having trouble passing smog, taking out the carbon helps your combustion process enough to improve your hydrocarbon figures.

[greenneck]

Thanks. Would this help with gas milage much? My jeep is only getting 11 mpg dang near stock. Oil changes, new plugs, proper inflation, nothing i know of helps. I was about to put some STP in my gas (87 with up to 10% ethenol) but my retired Ford Mech gramps said it was useless. Is seafoam differnt when used in gas?

And what are the dangers other than the o2 sensor?

[4.3L XJ]

Ethanol will not help your milage. Those of us that live in states with ethanol in our gas know this for a fact. Sea Foam just cleans out stuff. If your milage is bad, the best thing is to change out the O2 sensor. When they start wearing out they cause the mixture to run rich. No other dangers. Unless you know you need to clean the intake runners, just put it in the gas and call it good and just let it do its thing.

[greenneck]

Is there any way to know if it is actually the o2 sensor? I dont want to convince my dad that it needs replacing then having him get pissed when if it doesnt help.

Thanks!

[4.3L XJ]

Is your XJ lifted with taller than stock tires?

[greenneck]

Its not lifted. It has the biggest tires a stock one can fit. Im not certian what size though

[4.3L XJ]

OK, you should be getting around 16 mpg. My opinion is that the O2 sensor should be changed, especially if it has been at least 50,000 mi since it was changed. Those should be changed regularly, but are generally neglected when doing tune ups.

[stamp]

you should still be seein about 15 mpgs .... look into bg products ... bg44k to be more spicific .... thats the only stuff ive actually seen a real improvement with my mpg