Blue Smoke From exhaust!!! -

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post #1 of 14 Old 07-21-2008, 10:21 AM Thread Starter
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Blue Smoke From exhaust!!!

During a recent offroading trip to Kentucky, my 01 xj started to idle really rough and the exhaust fumes started getting a hazy blueish color and smelled really bad like fuel. Thought it might be the injector overheating after rhino-lining the hood, so I vented the hood, and put heat shield around all the injectors...problem went away. Now it's back and really bad. I get lots of smoke, bad idle and power is definately less. So I take it over to autozone to run the engine codes since the light is on - this is what I get...

#6 cylinder misfire
valve open

two seperate codes for these. Anyone every have similiar problem. Not sure if it's a bad injector dumping too much gas in, or if I have a bad ring. Can't be a valve stuck cuzz the piston would be ramming it and I'd get a nasty knock which is not present...just a very distinctive loud Puh-Puh-Puh_Puh from the exhaust with lots of blue smoke and a noticeable smell of gas.

Any Input would be helpful!!!

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post #2 of 14 Old 07-21-2008, 10:34 AM
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Time for an engine and/or a rebuild, most likely... blue smoke is a good sign you have something worn or broken, and that something will require major repairs.

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post #3 of 14 Old 07-21-2008, 10:55 AM
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Blue smoke means LOTS of burning oil.

My guess would be the ring is gone.

Good luck mate!

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post #4 of 14 Old 07-21-2008, 02:07 PM
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blue smoke tells me oil is burning which is probably worn rings. the popping sound could be a fouled plug if youre burning a lot of oil. i would pull all of the spark plugs. it will tell you a lot.

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post #5 of 14 Old 07-21-2008, 02:12 PM
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Yeah that 01 has the 0331 head, might just be your problem...

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post #6 of 14 Old 07-21-2008, 08:30 PM Thread Starter
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Hmmm....when I pulled the plugs before it got really bad, the plug in the rear which is the #6 was very black, and the rest were what looked to be normal. Mind you I had just changed the plugs a couple weeks earlier and had only taken the jeep out twice since the change out. The fact that the exhaust fumes smell really bad like gas has me wondering if it's something more along the lines of a bad injector ??? I've read that white smoke is a bad head gasket, usually because coolant is getting in the cylinders. I did notice quite a bit of white smoke before this turned into a problematic rough idling blue smoke. Way beyond my skill level though, not much on the engine stuff. Gonna run it to a local shop and see what they tell me....once I know I can probably change it out, just can't seem to figure out what it is. I appreciate all the input though.

My guages are also starting to play games on me. Sometimes they work, sometimes they oil pressure guage never reads normal, it's all over the place even after changing the sending unit. And sometimes I get the "no bus" error on the odometer. DANG GREMLINS are taking up residence in my jeep
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post #7 of 14 Old 07-21-2008, 09:31 PM
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White smoke is steam, water leak if it continues after fully warmed up otherwise just burning off condensation. Black smoke is soot, too rich. Blue smoke is oil burning.

Put a temporary mechanical gauge on the oil pressure port to verify. Most likely an electrical gremlin but it's peace of mind to know the oil pump is OK.
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post #8 of 14 Old 07-21-2008, 10:07 PM
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probably an oil burn, thats how i first noticed mine, 2nd time i took the jeep out i sunk it and sucked in water, none of my 4 wheelin friends told me to change the oil immediately. mine seems to only burn up in the higher rpms, and it does not feel like it is lacking any power, although opil pressure is only 15 psi with 20w-50
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post #9 of 14 Old 07-22-2008, 07:13 AM
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It kinda sounds like multiple problems. Blue smoke means your burning oil. Strong gas smell means your probably running way rich.

If the code you get is valve open, it might be dumping fuel into the cylinder which is giving you the smell. That would also make sense for the misfire code too.

It also sounds like the ring and or rings are bad. That's why it's burning oil.

Take it to a shop. See what they say and hope for the best.

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post #10 of 14 Old 07-22-2008, 07:34 AM
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another place where oil might be getting in, is the valve stem seal. If it is worn, also check the rubber seal itself.
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post #11 of 14 Old 07-22-2008, 08:13 AM
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Check the compression in #6. Then squirt some oil in it and check it again. If it goes up much then it's a ring.
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post #12 of 14 Old 07-22-2008, 11:23 AM
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The gas smell could be the same problem as the oil smoke - if the cylinder has no compression, or if the plug gets oil fouled, it could misfire...

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post #13 of 14 Old 07-22-2008, 12:21 PM
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Check and make sure the air filter isn't soaked in something like water or grease.
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post #14 of 14 Old 08-03-2008, 07:48 PM Thread Starter
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Ok...So I did a compression today and all cylinders hit between 125 - 140 on first crank, and by the third to fourth crank they peaked out at 170 - 180. It appears that I've got good compression in all cylinders. Decided to take apart the fuel rail and pull the injectors and test/clean them. Noticed that even the intake smells heavily like raw fuel. Injector ports were really dirty, and injectors were pretty nasty so I cleaned em up good, hit em with a 12v power source and they seem to be just fine. All the spark plugs ends were black, but not with carbon buildup, just burnt black like when running really rich. Noticed they were bosch platinums, so I'll be switchin them out w/ the champion truck plugs. Pulled the gas tank and I'm going to replace the filter/regulator, piece it all back together and seafoam it....see what happens. The filter appeared to have some really nasty debris in it.
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