Carbon Lots of it

[Outlander560]

Hey guys I have a 96 xj I6 5spd with 176,660 miles on it

I've done some searching but would like to see if you guys have tried any other techniques to remove carbon from your engine . Recently I experienced a misfire on cyl 1 and a random misfire i pulled the plug and noticed ground strap on the plug was pushed up into the electrode on the spark plug it didn't break anything and it did not have a knock, so I was thinking probably an excess of carbon build up on the piston head. Either way I did some other tests just for the miles on the vehicle I ran a compression and a leak down. At TDC I had 25% leakage on cyl 1 and 27% leakage on cyl 6 and I can hear air coming from the tail pipe so I'm thinking the carbon is built up around the exhaust valve seat causing the leakage. I got the shop borescope and looked inside the cylinders and they were loaded with carbon. I ran a motovac through the fuel system idling for 30 minutes while revving it up every 5 minutes holding at 2000rpms to help remove the carbon. I thought the motovac's detergent might help out and on a test drive the vehicle ran better. I brought it back into the shop and pulled the plugs nothing bent or broken but still the cylinders were loaded up with carbon. Aside from removing the head do any of you guys have experience with Seafoam? or GM cylinder head cleaner? Or any other carbon cleaners. I appreciate the info!

 

[cruiser54]

Have you ever heard of drizzling water into the engine at a high idle and removing the carbon that way? It's the only thing that got rid of the misfire on my buddy's 99.

 

[CSaddict]

Seafoam?

 

[87manche]

seafoam.

same thing as drizzling water in with the addition of some solvents, naptha pretty much.

Get the motor nice a warm.
Pull the brake booster hose off. Feed about a 1/2 can of te seafoam into the motor. Do this by pouring it into the vacuum hose, DO NOT PUT THE BOOSTER VACUUM LINE INTO THE CAN! Doin so will cause it to suck up far more seafoam than you intended and may hydrolock a cylinder. Once you get near 1/2 a can usage go ahead and pour enough in to stall the motor.

Now go ahead and find something to do for the next hour.
When you start it up be prepared for big clouds of white smoke. Take it for a drive and run it hard.

repeat as needed. Since you have a scope I'd be really interested in how well it actually works. Every high mileage car I've ever seafoamed runs better.

 

[Outlander560]

i will scope it and see what actual before and after is...and hopefully be able to put pictures up on here...first time using seafoam so its worth a try.

Cruiser I have heard of water it's like steam cleaning the cylinders but i'll see how the sea foam works first

appreciate the input guys

 

[cruiser54]

i will scope it and see what actual before and after is...and hopefully be able to put pictures up on here...first time using seafoam so its worth a try.

Cruiser I have heard of water it's like steam cleaning the cylinders but i'll see how the sea foam works first

appreciate the input guys

After BG 44K, which is excellent, valve spring replacement, the old water trick is what finally fixed by buddy's 99 xJ.

 

[magimerlin]

Does your scope have a picture taking function. Would be cool to see befor and after seafoam use. I use seafoam all the time in way above.

 

[xjbrian219]

Seafoam will do the job. GREAT STUFF

 

[Talyn]

Now go ahead and find something to do for the next hour.
When you start it up be prepared for big clouds of white smoke. Take it for a drive and run it hard.

x2 and by a hard run, drive it like you stole it. I recommend driving it for at least 20 minutes prior to get the oil up to temp. And don't baby it afterwards, that just leads to more carbon build up.

 

[bigalpha]

Does your scope have a picture taking function. Would be cool to see befor and after seafoam use. I use seafoam all the time in way above.

If it doesn't, just take a picture of the screen. Pictures are gold.

 

[Outlander560]

i'll do my best on the pictures...and thanks guys...looks like I will be trying sea foam first and check out the cylinders afterwards..will try and get pictures up by the end of this week

 

[gradon]

I was BAS today and watched a bunch of the Wheeler Dealers on Velocity(?) and on one of them they hooked up a carbon cleaning system to the shrader-valve on the fuel-rail of an XK8 for an hour(plugged the fuel return line). The guy said that the procedure costs ~L70 and the difference in the before and after HC levels in the exhaust were amazing. Anyhow, I've used Seafoam a bunch of times and it does remove some carbon, but how much is anyone's guess. Sometimes I'll use a whole can and let it soak for an hour.
P.S. Here's the TerraClean info: http://www.terraclean.net/product.php?id=1
From the testimonials on the video on the site, some Ford and Dodge dealers offer the service.

 

[twodoorXJ]

Carbon is hard stuff to get rid of once its highly built up inside your engine. That stuff is difficult to take off with a wire wheel, i doubt that any cheap cleaner is going to miraculously (sp?) remove all the carbon build up

 

[Outlander560]

you are right...and either way its worth a shot before and after on with the bore scope....worse comes to worse i remove the head...which is a project but not that big of a deal

 

[boncrshr]

This looks like a good idea...I am going to try it on my 00XJ with 225K. I have seafoamed my outboard in a similar manner and it is amazing how much smoke it puts out...it has to be burning some carbon for sure.

 

[Wayne Sihler]

Try switching to Shell brand gas, I had the intake off my 96 to replace the injectors(long story) and noticed the carbon build up on the back of the valves. My mechanic friend said there was a service bulletin for Chevy,that delt with a mis-fire caused by carbon build up.Fix was to switch to Shell gas...

I did not totally believe that but did switch to Shell for most of my gas,price was same for all brands in my area,,,,after about 3 months had to replace exhaust header(crack) and had intake off again,,,,a noticeable decrease in carbon on the intake valve,,,,,, so YMMV......

 

[Outlander560]

interesting about the shell gas....picked up the sea foam....i ill let you guys know what happens...or if sea foam is just all smoke and nothing else

 

[boncrshr]

I tried the Seafoam through the brake booster vacuum hose and it was crazy! I have a 2000XJ with 225K, and I am prompt with oil changes (Rotella synthetic) and I run Marvel in the gas on most tanks. That being said, the amount of smoke coming out was startling. I was worried some of my neighbors might report me to the EPA...it looked like the smoke screens that some battle tanks can put out. The Jeep definitely seems to run better afterward.

 

[gajeepguy]

I've got to do a good flush too. I did vc gasket today and found this

 

[Talyn]

that is awful. Clean it out as best as possible and use a good oil.. maybe do some short changes with a diesel oil.