Multiple Symptoms, any suggestions?

[wolfsnatcher]

I have a '96 4.0 2wd XLT. It has a 103000 miles and other then tires, brakes, plugs and thermostat, has required very little corrective maintenance since purchased with 34000 miles. I installed a K&N air filter about 2,000 miles ago.

Here are my symptoms, any thoughts?
-Intermittent Check Engine Light
(AutoZone scan code was for Cat. Convertor)
-Intermittent low moaning that gets louder when the seal on the air intake is loosened.
-Sometimes sluggish and weak running with low MPG
-Water Temp. gauge sometime will pop up into th H for a few seconds, even when engine is obviously still cool.

Im ready for any thoughts, I just wont be able to try any suggstions till I am back onshore next week. I would like to be able to start looking for the parts and have what I need available when I get home.
:chug

 

[Howard]

Welcome

Lets start with the simple things first.

Running weak/sluggish:
When you installed the K&N did you a) clean the MAF and b) reset the computer?
Plugs and leads may well need changing life span approx 100,000
I think the moan is normal with K&N filter


Temp gauge:
Sounds like either the thermostat is playing up or the temp sensor is shorting.

Thats all I can think of at the momment. Hope this helps.

 

[DarkFox1]

I'm not a 4.0 guy, not really much of a 5.0 guy lol, but that moan, if its beyond the normal levels that you would get with the filter could be a bad IAC. if you reset the computer and cleaned everything up like howard said that is.

the sluggishness.. I just chock up to life as usual with mine, but if this is an obvious change from like.. driving yesterday, you may want to look into changing the thermostat.

if neither of these are your solution, and you have had the cats dealt with, I'd go have a diagnostic scan and have them print it out, perhaps that would give you some leads.

also.. if you are running on really bad mileage, and perhaps a bit rich, you could be in open loop and/or have a failing o2.. I would think those would trip the CEL tho..

good luck, I spent close to probably $1k on sluggishness/mileage problem testing and never found a thing lol, not trying to scare you, just.. sometimes these problems are hard to pinpoint

 

[aldive]

Are the O2 sensors original equipment? I would replace them if so.

Have your cats checked.

Have you replaced the spark plugs/wires? If not, do that right away.