Seafoam - good or bad?

[Pacfanweb]

These are the plugs I used.

http://www.amazon.com/Bosch-FGR8LQP0...&vehicleType=5

Factory is usually the best for plugs. And whatever they're "made of" has nothing to do with how well the engine runs. All the fancy plugs do is last longer, which is nothing to sneeze at since access to changing them is pretty tight in some cars.

Copper-shortest life
Platinum-#2
Iridium-Longest life.

So as long as any of those plugs are the correct heat range for your engine, there will be no noticeable difference in the way it runs, unless your plugs were going bad to start with.

I can personally vouch for iridium. My 04 Suburban has over 190k and the plugs are original Still runs great.

 

[monkeydelmagico]

Alot of people swear by the stuff. I've tied it on a few occasions with no noticable difference. If you've already run fuel cleaner why do it again?

With that kind of mileage and the symptoms you describe I'd look into leaky injectors and/or malfunctioning IAC valve.

I would also echo using only OEM spec on Hondas. They can be finicky about aftermarket.

 

[white]

Do you have an exhaust leak? I have a 98 with almost the same mileage and my exhaust manifold had a crack around the pipe coming from the #4 cylinder, before it got to the upstream O2 sensor. You can visually check by pulling the heat shield. After changing it, I saw another crack forming from the backside. My car sounds a lot better now.

 

[Meghan54]

I got the car when it had 84,000 miles on it and I didn't change the plugs until 153,000 miles. I'm relatively certain they were the originals. lol Frankly, I was surprised at how well the car was still running with plugs that old.

I can try regular AC Delco plugs and see if that helps. I simply got the Bosch +4s so I wouldn't have to gap them.

God NO!! Not Bosch plugs!!!

Bosch +4 are junk, if not an illusion at somehow shrouding the spark helps performance. And I think you'll find the days of having to gap plugs is long gone, except in rare situations and very old vehicles. The OEM Delco plugs, if that's what you go buy, will most likely be pre-gapped and state not to try to gap them at all.

I try to run NO Bosch if I can help it, well, maybe an oxygen sensor, in a pinch. But again, OEM is best....like with the oxygen sensors I just replaced this morning. Bought Denso because that's who the OEM was for those sensors on my truck and the Denso branded ones were a tad cheaper than AC Delco branded, which are Densos anyway, once you opened the box and looked at the sensor.

But I've used a ton of Bosch on my '95 Volvo as it was the OEM for a bunch of the stuff on the car...ignition, etc.

 

[Scarpozzi]

Mass Airflow Sensors and Oxygen Sensors can also start to throw mixed, if not faulty data after a few years of use without actually showing up as 'bad' to the computer.

You might want to look at throttle body cleaner, mass airflow sensor cleaner, and perhaps fuel injector cleaner.

 

[bryanl]

My wife and I love our little 2007 Honda Civic mileage whore. It's close to hitting 168,000 miles already thanks to my wife's 90 mile round trip to work. Lately we've noticed it's idling a little rough and where it used to get 33-35 mpg during her normal commute, it's now getting 30-32 mpg. I've replaced the spark plugs with high quality iridium plugs, changed the air filter, routinely change the oil every 6,000 miles with Mobil1 full synthetic, and take pretty good care of the car. I've put two bottles of fuel treatment through it over the last 3,000 miles but hasn't really had an effect.

Is seafoam something worth trying? I've heard good and bad. Or am I probably barking up the wrong tree and I should look at something else causing the rough idle and loss of mileage?

Don't use it. While engine cleaners can free up old deposits, those deposits can then clog oil passages and starve parts of the engine of lubrication. And while it would seem that dissolving varnish from the cylinders and piston rings would be a good thing, it can actually make rings stop sealing as well and greatly increase oil consumption. You have a modern engine, not something from the 1940s (when Seafoam was invented) that runs rich (intentionally) on gasoline and oil containing no engine-cleaning detergents, has 20% leakage and no positive crankcase ventilation.

You may need to clean out your throttle body and plate with solvent made for that purpose and a bristle brush (not wire brush). Use factory original spark plugs, not 'performance' plugs, even if they're made by the same company. Hondas prefer NGK or Denso plugs, sometimes only NGK.

 

[phucheneh]

God NO!! Not Bosch plugs!!!

Bosch +4 are junk, if not an illusion at somehow shrouding the spark helps performance. And I think you'll find the days of having to gap plugs is long gone, except in rare situations and very old vehicles. The OEM Delco plugs, if that's what you go buy, will most likely be pre-gapped and state not to try to gap them at all.

I try to run NO Bosch if I can help it, well, maybe an oxygen sensor, in a pinch. But again, OEM is best....like with the oxygen sensors I just replaced this morning. Bought Denso because that's who the OEM was for those sensors on my truck and the Denso branded ones were a tad cheaper than AC Delco branded, which are Densos anyway, once you opened the box and looked at the sensor.

But I've used a ton of Bosch on my '95 Volvo as it was the OEM for a bunch of the stuff on the car...ignition, etc.

I don't always agree with Meghan54...but when I do...

...it's because Bosch plugs blow goats.

I can agree that running factory Bosch plugs (not that quad cathode crap) in a car that came with them (Germans) is not a bad idea. But I generally say NGK or Denso > all else. Japanese spark plugs: They Just Work.

OP sounds like he just needs to clean the throttle. I've fixed cars that would barely idle, even die upon throttle application, by simply cleaning a moderately dirty electronic throttle. Use the [supposedly] electronic-safe cleaner, not carb clean. I can't say that I'm sure there's a difference, but when one $5 can will clean like ten throttles, I don't see any point in taking the possible risk.

I don't think Seafoam or similar does anything before the combustion chamber. Makes no sense to think that it does, IMO. I guess if you run enough of it, and it has a high enough detergent content, you could loosen up crap in the intake, including gunk around the injectors. But that's not really the same as clearing a 'clogged' injector...that's internal. And if it does do anything in the intake, it would take time.

Clean throttle and 'Italian tune-up' always works for me. An actual triggered relearn is rarely necessary. By that, I mean a throttle 'initialization', as typically triggered by a scan tool. Sometimes (early Nissan electronic throttles are all I can think of off-hand) a really convoluted sequence of key turns or some such can be used to trigger it without a scan tool. And to even further clarify (sorry), 'scan tool' doesn't mean a generic OBD2 adapter for your phone/tablet/laptop. You have to go through the manufacturer-specific protocol.

...but like I said, it's rare that you will need that. Worth a google before you do it, though.