Burning smell from 03 Jeep... (pics attached)

I've noticed a burning smell and have seen some smoke coming out of the hood and finally saw what has been burning:

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It looks like it's some wire that is going into the exhaust system...? Anyone know what it is? And how I can replace it?

Thanks,

Chris

That is an O2 sensor. I'm going to say you've got a lot going on wrong in your rig. That looks like oil... If oil is leaking past the valve seats and rings you're looking at big $ to get that fixed. The cat may be toast also.

Warren.fischbeck said:

That is an O2 sensor. I'm going to say you've got a lot going on wrong in your rig. That looks like oil... If oil is leaking past the valve seats and rings you're looking at big $ to get that fixed. The cat may be toast also.

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Hmm.... you're right it looks like oil. In fact, after I went under the Jeep and looked more closely, it's definitely oil falling from above onto the sensor...

I checked the oil level, and it's still in the "safe" range. I don't know how long this issue has been going on, but I remember smelling a burn smell for a while...few months.

Should I take it in to the Jeep dealership?

Obviously finding the leak/s is imperative.
Look at your valve covers closely to make sure it is not leaking down from there.
That would be a easy fix...

LibertyTC said:

Obviously finding the leak/s is imperative.
Look at your valve covers closely to make sure it is not leaking down from there.
That would be a easy fix...

Click to expand...

I'm having some trouble finding the valve covers.. :shrug: ...Can you help me locate them?

RChris173 said:

I'm having some trouble finding the valve covers.. :shrug: ...Can you help me locate them?

Click to expand...

Here you go

Warren.fischbeck said:

Here you go

Click to expand...

Thank you for the diagram. I checked them myself and noticed that one of them was able to be tightened a little and cleaned some oil residue that was around it. I'm not sure if that did anything...

I ended up taking it to Tires Plus (where I get the oil changed and buy tires), and they were able to check underneath it and claim that the oil is leaking out of the valves because the gasket is not sealing properly. They didn't think that the bolts could be tightened up more and recommended I replace the gaskets.

I declined letting them do any work to it and got an estimate from them totaling $366 for the gasket and labor. (It looks more difficult to get the passenger side gasket out because of all the components around it.)

Is this normal for a 2003 Jeep with 68,800 miles to have a gasket leak??

Thanks,

Chris

Eventually all seals like to leak.
I know in chevy small blocks, the valve covers are a real leaky set up, using spreader bars across the bolts, and polyurethane gaskets help but many still leak. (ask me how I know)
If only one cover is leaking then attention can given to that side.
Get a few quotes. Yes there is some stuff that has to be moved away to remove the cover. Later I will look at the FSM to see if this is something you might want to tackle.

clean the rocker covers up and make sure you snug the bolts. Keep everything clean so you can find the culprit. might get away with just snugging the bolts. replacing those gaskets isnt usually too difficult on most vehicles.

I could not find a link to the 2003 FSM.
Here is a link to the 2005 FSM. http://www.easy-share.com/1909827450/2005-KJ-ServiceManual.PDF
And search in pdf "Cylinder Head Covers" on my 04 manual it was page 1276.
Air hoses etc,Fuel injector clips/connectors and such has to be moved out of the way......
Does not mention any special tools needed.

196,000 miles, don't leak a drop of anything on engine. I do not believe any leak is normal.

ridenby said:

196,000 miles, don't leak a drop of anything on engine. I do not believe any leak is normal.

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Wow, that's a lot of miles! Obviously leaking isn't "normal", but I'm just shocked that for an engine with as "low" miles as it has leaking oil from the gaskets is occurring...guess I'm trying to gauge the frequency of this problem occurring with other Jeeps...

What kind of things could contribute or cause oil leaks like this one to occur? Is there anything that I might have done that could contribute or lack of an action on my part to prevent??

Thanks guys

Most likely culprit of a leaky valve cover was a bad installation, or possibly a bad PCV valve. A bad PCV valve can cause excess pressure in the crankcase and cause gaskets and seals to leak.

Engine leaks are NOT normal on the 3.7L with any amount of miles on it. This is one really tight engine. Just sounds like bad luck. I'd replace the gasket with Mopar, tighten up really good and be on my way hoping it never happens again.

Just thought I'd post an update.

I replaced the PCV valve to no avail. Since the passenger side valve cover gasket was difficult to access I decided to take it to a Jeep dealership and have them replace it. I had already purchased the gasket set (Felpro brand).

The old gasket was uneven in thickness in a corner which was where the leak must have been coming from as I do not have the leak anymore!