Jeep pinging more.

[AVB]

Originally Posted By: Chris142
The Jeep 4.0 valve rotators won't totate the valves under 3500 rpm. Carbon will build up on the back of the valves and the gas will soak into that,boil off and cause a lean condition. Go take it for a spirited drive. Get it wound up and see if that improves it.
There is a TSB about that, I couldn't remember if it was for the 4.0 or 4.2.

I would run a can or two of combustion cleaner through it, maybe some water. I used to mix solvent and water together, it was something I read about in one of my engine performance text books 20 years ago.

 

[Nick1994]

Originally Posted By: Chris142
The Jeep 4.0 valve rotators won't totate the valves under 3500 rpm. Carbon will build up on the back of the valves and the gas will soak into that,boil off and cause a lean condition. Go take it for a spirited drive. Get it wound up and see if that improves it.
That sounds like a good idea, go for a drive in the mountains and downshift and let it sing.

 

[KCJeep]

I run MMO in the gas in mine constantly, have now for 6 years straight and no ping at all, runs smoother with it and gets a hair better gas mileage too. Much better long term option than TCW3 IMO.

I also get the rpm's up on it once in awhile like others mentioned. Cruise for a bit at over 3500 rpm...easily accomplished on city streets if you manually put it in second, or on the highway if you turn off the OD.

Mine doesn't use a perceptible drop of oil between changes either, most 4.0's don't.

 

[Linctex]

Originally Posted By: KCJeep
I run MMO in the gas in mine constantly, have now for 6 years straight and no ping at all, runs smoother with it and gets a hair better gas mileage too. Much better long term option than TCW3 IMO.


I have been using 2oz MMO (in Top Tier gas) to 4oz (non-top tier) per 10 gallons
and have been getting close to 20 mpg at times in my 4.6 liter F150

I'm going to mix MMO and TCW-III 50/50 and start to use it at 1oz-2oz per 10 gallons (1oz in 5) in all fuels.

 

[BAJA_05]

When was the last time you gave it a tune up? Plugs/wires/cap & rotor? Just throwing that out there also.

 

[red7404]

could be the EGR valve letting to much gas by. or i had a 84 ply that the intake had a bad crack in the intake manifold letting the ext gas into the intake. the give away was that the plugs had black on them like they had been in the exhaust manifold. which in a way they was.

 

[littleant]

BrocLuno. No distributor but has a camshaft position sensor. Not sure if sensor can be adjusted. May be the issue but have no codes. Will try a piston soak first. Bore scope would be nice about now. Tough winter for the jeep. Real cold. Has had piston slap for the last 100,000 mile. Goes away at operating temp. Will definitely be doing the 2 stroke oil. Thanks for the input guys.

 

[dlundblad]

Just throwing this out there, are you certain she's getting up to full operating temperature?

Your driving style points to that being the cause, but you seem to take care of that by the 50 mile weekly drives.

Never used the MMO in my Jeep. I tried Seafoam once and was expecting a large white cloud.. Very disappointed, but I guess that meant my Jeep's internals were clean too.

 

[littleant]

dlundblad. The only way it will reach 210 operating temp is by letting it idle about 10 minutes in winter. Summer 5 minutes. OCI never go past 3,000 miles with oil and filter change. Winter oil is changed in spring even if only 1,000 miles because of short trips. We use only the jeep in winter to preserve the 2010 mountaineer that stays in garage.

 

[Chris142]

Originally Posted By: red7404
could be the EGR valve letting to much gas by. or i had a 84 ply that the intake had a bad crack in the intake manifold letting the ext gas into the intake. the give away was that the plugs had black on them like they had been in the exhaust manifold. which in a way they was.
the engine he has does not have an egr.

 

[littleant]

Well took the jeep out today quick run to grocery store (38 miles round trip) and it through a code P0138 bank 1 sensor 2 high voltage. I do not think this would cause excessive pinging. Correct me if I am wrong. I believe sensor one on bank 1 and 2 control air fuel mixture. I did notice jeep running rough on the run but not missing. Thoughts. Will fix this code first.

 

[littleant]

The Jeep 4.0 valve rotators won't totate the valves under 3500 rpm. Good God if this is true I have had this jeep 6 years and MAYBE it's seen 3500 rpm 1 or 2 times in 100,000 miles.

 

[Chris142]

Originally Posted By: littleant

The Jeep 4.0 valve rotators won't totate the valves under 3500 rpm. Good God if this is true I have had this jeep 6 years and MAYBE it's seen 3500 rpm 1 or 2 times in 100,000 miles.
common enough for Jeep to post a tsb about it.

http://www.jeepforum.com/forum/f9/exhaus...#/topics/569035

 

[artificialist]

Originally Posted By: littleant
Well took the jeep out today quick run to grocery store (38 miles round trip) and it through a code P0138 bank 1 sensor 2 high voltage. I do not think this would cause excessive pinging. Correct me if I am wrong. I believe sensor one on bank 1 and 2 control air fuel mixture. I did notice jeep running rough on the run but not missing. Thoughts. Will fix this code first.
I think bank 1 sensor 2 is the post-cat sensor that checks if the catalytic converter is properly removing smog. It doesn't seem likely to cause a ping, but I'm not sure.

 

[littleant]

Linux just wanted to let you know that your recommendation to add 2 cycle T3 to the gas WORKS. Used Pennzoil T3 synthetic blend. I did not use sea foam first just the T3. After the first full up did not notice any change in pinging. After the second fill the pinging was reduced by 50%. After the third fill up pinging was reduced by 90%. I AM A BELIEVER. IT JUST FLAT OUT WORKS. Will continue to use it at every fill up. Also added it to my 2010 4.0 mountaineer. Guys I recommend doing this. It's not a placebo effect. There was no mistaking excessive pinging and then it's gone. Thanks linux and everyone else that said it works. What a great forum bitog is the best