Need advice. Carbon build up in jeep wrangler.

[ElGuapo]

I just got my grandpa's 97 jeep wrangler. It's the 4 liter straight six with only 90,000 miles. Trying to get it to pass smog. I just had a new exhaust manifold put on due to an exhaust leak. My mechanic recommended to run a quart of sea foam through it to clean it up since it has a lot of carbon buildup because my grandpa would always just cruise around real slow in it. But everything I read is 50 50. Either they say it works or causes more problems. What do you guys think?

 

[Universal Elements]

I just got my grandpa's 97 jeep wrangler. It's the 4 liter straight six with only 90,000 miles. Trying to get it to pass smog. I just had a new exhaust manifold put on due to an exhaust leak. My mechanic recommended to run a quart of sea foam through it to clean it up since it has a lot of carbon buildup because my grandpa would always just cruise around real slow in it. But everything I read is 50 50. Either they say it works or causes more problems. What do you guys think?

I have a 1987 Wrangler with a 6 cylinder. Passes smog with no problem in California. Had to change my exhaust manifold, too. They all leak. I would change the plugs if they haven’t been changed. But run Redline first and change the plugs after. Redline works and just drive normally and get on it too. Here is a link to the Redline. Available a lot of places.

http://www.redlineoil.com/si-1-complete-fuel-system-cleaner

 

[spectracular]

After watching “project farm” on YouTube do a video on Seafoam, I’d be included to give it a try

 

[Universal Elements]

After watching “project farm” on YouTube do a video on Seafoam, I’d be included to give it a try

I'll add a few words on the Seafoam cleaner. It contains no beneficial fuel detergents. However it is loaded with alcohol, which when burned gives the impression of better ignition. So it is basically a "one tank wonder". Better to spend your money on a valid polyether amine fuel cleaning product like BG 44K or Techron in my opinion. My motorcycle friends all rave on the Seafoam, but in actuality all it does is burn faster, thus fooling us into thinking it is a wonder drug cleaner. So I got curious and analyzed the Seafoam. It turned out to be just plain isopropyl alcohol, a dilution solvent, and a small percentage of light mineral oil. No significant metal additives or detergents to be found.

Seafoam is really only useful when used through the throttle body/intake manifold. Even then, plain old hot distilled water does a good if not better job at removing carbon that way.

Redline SI-1 and other PEA cleaners (Regane, Techron, BG44K, etc) are used primarily to clean out from the gas tank to the injectors to ensure proper fuel readings and delivery. When it is combusted, it does a decent job of cleaning piston tops and up the valves, but not as good as water.

 

[bk2drvr]

Lol...all this advice and no details on why it doesn’t pass smog.

Let’s start from the beginning.

Why is it not passing smog? Check engine light? Smog guy must have said why it didn’t pass smog.

How do you know you have carbon build up? I’m not sure there were direct injection motors in 1997 so what carbon is your mechanic referring to?

More details please.

 

[Ouderkirk]

I just got my grandpa's 97 jeep wrangler. It's the 4 liter straight six with only 90,000 miles. Trying to get it to pass smog. I just had a new exhaust manifold put on due to an exhaust leak. My mechanic recommended to run a quart of sea foam through it to clean it up since it has a lot of carbon buildup because my grandpa would always just cruise around real slow in it. But everything I read is 50 50. Either they say it works or causes more problems. What do you guys think?

The 4.0 inline 6 is a great motor that has an issue coking the PCV system. There is a hot spot in the head that causes the oil to cook. You are going to need to go in and clean the entire PCV system in order to get it to pass.

 

[SBMech]

I'll add a few words on the Seafoam cleaner. It contains no beneficial fuel detergents. However it is loaded with alcohol, which when burned gives the impression of better ignition. So it is basically a "one tank wonder". Better to spend your money on a valid polyether amine fuel cleaning product like BG 44K or Techron in my opinion. My motorcycle friends all rave on the Seafoam, but in actuality all it does is burn faster, thus fooling us into thinking it is a wonder drug cleaner. So I got curious and analyzed the Seafoam. It turned out to be just plain isopropyl alcohol, a dilution solvent, and a small percentage of light mineral oil. No significant metal additives or detergents to be found.

Seafoam is really only useful when used through the throttle body/intake manifold. Even then, plain old hot distilled water does a good if not better job at removing carbon that way.

Redline SI-1 and other PEA cleaners (Regane, Techron, BG44K, etc) are used primarily to clean out from the gas tank to the injectors to ensure proper fuel readings and delivery. When it is combusted, it does a decent job of cleaning piston tops and up the valves, but not as good as water.

Da Fuck bro...closet mensa mechanic? Haha Crazy the science out there if you look closer, I swear by BG stuff, it's unbelieveable.

 

[HALLETT BOY]

Dump some water down the throttle body , hopefully that’ll clean it out . That engine has no EGR system and the state keeps lowering the standards for NOx , hard to get through. Make sure the 3 way cat is working .

 

[t&y]

LOl.. WTF....

 

[Universal Elements]

Da Fuck bro...closet mensa mechanic? Haha Crazy the science out there if you look closer, I swear by BG stuff, it's unbelieveable.

Hey I love punishment, so I tinker in a lot of old cars. In California, it’s an art to pass smog on some of our stuff. Have a lot of practice on older bmws. The 1999 to 2002 could be a real challenge. My 1979 Porsche is a nightmare. BG stuff is great but not always available everywhere. So I mentioned Redline because I’ve seen it more places.

 

[BHC Vic]

My buddy mike who was a super at the time lit up the tires in a parking garage at a job site. Company truck... the senior super saw him and yelled what the fuck are you doing. Mike quickly replied getting rid of the carbon build up. Funny shit. That’s all I got

 

[2Driver]

Dont use sea foam

 

[LargeOrangeFont]

A little rubbing alcohol in the tank when it is below 1/4 full will help it pass smog if HC’s are a problem. Fill it up with fresh gas right after the smog check though.

 

[monkeyswrench]

I have used some stuff from FMP, a wholesaler for repair shops, called De-Carbon. It's a two bottle thing. One in the tank, the other is an aerosol to run in the intake. It's sensor and cat safe. When doing the intake, your exhaust will look like a Cummins rolling coal. It works really good on coked intake valves and crusty pistons...used the camera the first time to how it worked. Other companies make comparable stuff, but I don't know if it's available in Cali.

As for water down the intake...on old engines I use a mix of rubbing alcohol and windex. Redneck as hell, but helps to de carb pistons and unstick rings. Once again, OLD stuff. Things like Model A and T Fords and John Deere's that have been sitting for decades. Get them running, throttle them up and spray. Stop squirting as it tries to die, let the R's come back and repeat.

 

[havasujeeper]

Ya gotta ask why it is not passing smog before throwing lots of crap down its throat.

 

[havasujeeper]

Remember, just a battery disconnect could cause it to not pass smog for a hundred miles or so.