Jeep is smoking a tad...

[Cpt Marvel]

Once in a while more than a tad. But usually just a little. Smells like oil. I did a compression test on it. First crank, ALL of the cylinders jumped up to 150 and then to dropped to 120, by the 5th-7th crank they were all at 180. Did the wet test and no change. All the plugs looked good except two insulators were slightly darker than the others. Plugs have about 1,600 miles on them. Slight bit of heat glazing. No knocks, rattles, pings or chatters. Engine runs so smooth that sometimes I have to check the tach to make sure its running. I do have codes for bank 2 O2 sensors, which I am going to go work on changing right now, with NTK replacements. Could bad O2 sensors cause the engine to smoke by making it run rich? I guess I'll find out. Putting a pic of the plugs in.

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[RenKJ]

That's some extensive testing for an oil smell, if you haven't done it yet i would guess its the valve cover gasket leaking occasional oil drops onto the exhaust, otherwise id say check the ccv tube for a crack at its T connector

 

[Cpt Marvel]

That's some extensive testing for an oil smell, if you haven't done it yet i would guess its the valve cover gasket leaking occasional oil drops onto the exhaust, otherwise id say check the ccv tube for a crack at its T connector

No, it's blowing smoke outta the tail pipe. THATS what smells like burning oil. Of course I can have decent compression (206 k miles) and still have leaking valve guides or seals. These 3.7s have rubber seals on the valve stems like Chevys? At any rate, the compression test makes me feel better about the rings.

 

[ltd02]

These 3.7s have rubber seals on the valve stems like Chevys?

Yes they do. 206k is pretty good. Hope mine makes it that far (172k currently). :favorites13:

 

[Cpt Marvel]

Yes they do. 206k is pretty good. Hope mine makes it that far (172k currently). :favorites13:

I'm not sure it's the original engine. I suspect it's not, but the serial number seems to behind the power steering pump, and I'm not pulling all that crap just to check. And I've changed out the instrument cluster, so now it only has 140k. Pretty good drop, ehh!

 

[M38 Bob]

Are you actually having to add oil between changes? If so, how much, how often? Even a quart every 1,000 miles isn't anything to get your bowels all in an uproar about.

Bob

 

[Cpt Marvel]

Are you actually having to add oil between changes? If so, how much, how often? Even a quart every 1,000 miles isn't anything to get your bowels all in an uproar about.

Bob

I had to add a qt after about 1500. I know it's not a Honda. Yeah, the thing does leak some. If it didn't I'd be as surprised as when I am seeing trailer lights working here in Tennessee.

 

[Cpt Marvel]

But I just got the O2 sensors put in. See what happens.

 

[RenKJ]

I had to add a qt after about 1500. I know it's not a Honda. Yeah, the thing does leak some. If it didn't I'd be as surprised as when I am seeing trailer lights working here in Tennessee.

I totally misunderstood, i was thinking you smelled it in the cabin, that is a decent bit of oil to be losing

 

[LibertyTC]

Ya with higher mileage engines,as it wears, so do the valve guides seals, & rings.
Sometimes you do get some blow by smoke going on, noticed as blue at startup, after sitting overnight for instance.
If it becomes bad enough many go to a thicker oil, or even add a bottle of blue STP oil treatment.
Check the PCV valve to make sure it rattles and is clean & free from build ups of gunk.
Oil leaks, ya what fun. Valve cover gaskets can be replaced as they are a main source for dripping down under the hood, and all over if it is bad enough.
What scares me is, thinking about replacing a KJ oil pan gasket.

 

[Cpt Marvel]

If it becomes bad enough many go to a thicker oil, or even add a bottle of blue STP oil treatment.

That's my plan at this point. Possibly a slightly hotter plug to help it burn off.

 

[RenKJ]

Ya with higher mileage engines,as it wears, so do the valve guides seals, & rings.
Sometimes you do get some blow by smoke going on, noticed as blue at startup, after sitting overnight for instance.
If it becomes bad enough many go to a thicker oil, or even add a bottle of blue STP oil treatment.
Check the PCV valve to make sure it rattles and is clean & free from build ups of gunk.
Oil leaks, ya what fun. Valve cover gaskets can be replaced as they are a main source for dripping down under the hood, and all over if it is bad enough.
What scares me is, thinking about replacing a KJ oil pan gasket.

Is it worth getting valve / lash adjuster work done at that mileage if the engine is still running ok? Just to bring it back a bit?

 

[LibertyTC]

Probably not. Doing the top end still leaves the bottom end worn and inevitably the whole engine has to be replaced or rebuilt if possible.
That being said, if the Jeep has to pass emission testing, and you pull up smoking like a blue fog, well then, there are some choices to make ahead.
In the meantime oil is cheap, rebuilding or replacement not so much.

 

[M38 Bob]

That being said, if the Jeep has to pass emission testing, and you pull up smoking like a blue fog, well then, there are some choices to make ahead.
In the meantime oil is cheap, rebuilding or replacement not so much.

Just put some CRD stickers on the side of it. :happy175:

Bob

 

[Cpt Marvel]

Is it worth getting valve / lash adjuster work done at that mileage if the engine is still running ok? Just to bring it back a bit?

Depends. Body is in good shape, interior is fair. Completely new cooling system. New front upper and rear upper control arms and ball joints. Runs and drives good. Heads? Yeah I'd spend the 3-600 on those. Engine or transmission. It would most likely be time to say bye bye.

 

[RenKJ]

Depends. Body is in good shape, interior is fair. Completely new cooling system. New front upper and rear upper control arms and ball joints. Runs and drives good. Heads? Yeah I'd spend the 3-600 on those. Engine or transmission. It would most likely be time to say bye bye.

So by heads so you mean getting them surfaced along with valves/rings/adjusters? Or would getting head work alone be in 300 to 600 range?

 

[M38 Bob]

Doing a head job has always been nearly guaranteed to cause large increase in oil useage.

Bob

 

[LibertyTC]

Ya but ...
This is how I pay back my 7am lawn mowing Neighbor !!
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The "Blue Fog" !!

 

[Cpt Marvel]

Doing a head job has always been nearly guaranteed to cause large increase in oil useage.

Bob

I'll tell my girl friend that!

 

[Hockeygoon]

If it becomes bad enough many go to a thicker oil, or even add a bottle of blue STP oil treatment.

That's my plan at this point. Possibly a slightly hotter plug to help it burn off.

Adding "STP" (honey oil) only starves parts of the engine for lubricant making your issues worse. Much better off just checking the oil more often and adding as needed. Moving up a to 15W40 might help a little but nothing fixes it except making the needed repairs.