Good evening everyone,
I'm a long time lover of jeeps, wife finally let me get one. I've got a stock and extremely clean 2000 Cherokee classic 4.0 inline six. (Not sure what abbreviations y'all use mean yet)
Anywho, I'm looking to make a few minor upgrades. First things first. The light housing and relay.. can anyone of you point me in the direction of some quality equipment? Brands, type etc etc.
Also I'm having a really rough idle and crank only when I have only npticed it when the A/C is on.
Lastly, my oil pressure gauge seems to fluctuate between 22 to 45 depending on Ron and acceleration. Granted I've got high-ish miles (almost 200k)
Not pulling any codes, I'm assuming a dirty IAC? Thoughts?

 

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hop

 

I've heard about that issue. head is good, oil pressure stays around 45-50 while driving. Idle is around 22. Just didn't know of this was normal. Jeep is in excellent shape for it's age.

 

I just got a 98 with 96k on the odometer. The oil pressure around 20 at idle freaked me out too but apparently it's pretty much normal.

 

That's what I'm gathering from everywhere, oil pressure fluctuation is normal with these. As long as it's in a certain parameter. Either of you know what this rough cold start and rough idle with a.c. on could be?

 

The spec for hot idle oil psi is around 13+ psi for a 4.0. So i think you're good there.

Don't know what you mean by AC will definitely put one hell of a load on the engine especially if the AC compressor has problems.
Even though they're designed to start with AC on, right or wrong i never start a cold engine with AC enabled. After idling a few minutes after a cold start then i turn on the AC.

You might want to start by cleaning the IAC and take it from there.
At 200k miles, its about due!

 

Rough idle and crank, only with A.C. on for the idle part. Is what I was meaning.

 

i can

 

The light housing and relay.. can anyone of you point me in the direction of some quality equipment? Brands, type etc etc.
- Check this thread for some DOT approved LED options as well. The Inspired Engineering LED drop in replacements are very interesting - someone just ordered a set and hopefully they will post a "review" of sorts after receiving/installing them

https://www.cherokeeforum.com/f59/mo...ussion-227643/

Also I'm having a really rough idle and crank only when I have only npticed it when the A/C is on.

- Check the AC Compressor bearing. With the belt off, you can spin the pulley and listen for the pulley bearing, and if you jumper the AC Compressor Clutch you should be able to turn it and feel for any roughness. Pull the AC Compressor clutch (you need an AC Compressor holding tool to get it out), and scuff it with a wire wheel to remove any rust. Mine had not worked in probably 5+ years but I got lucky and my bearing was fine, just the clutch was rusty and causing it to disengage for no reason. There is a shim in there that you can remove if your clutch is worn to get more service life out of the compressor (google for pics)


Lastly, my oil pressure gauge seems to fluctuate between 22 to 45 depending on Ron and acceleration. Granted I've got high-ish miles (almost 200k)
- 15 psi to ~60 psi is within the FSM normal oil pressure range. Sounds right on the money to me (25 idle, 40+ at cruise RPM)

Not pulling any codes, I'm assuming a dirty IAC? Thoughts?


- I would pull the throttle body out and clean it out thoroughly just for fun. 4 bolts + a clamp for the air filter is all it takes. Remove the IAC and clean it thoroughly, same with the throttle body housing and innards (after removing the sensors). TPS seems especially easy to kill.

Since the Jeep is new to you, I would recommend a full tune-up (fluids, spark plugs, grease all chassis points, etc). Helps assess the condition of the motor and identify any maintenance points

EDIT:
Definitely assess the cooling system and replace stuff before it overheats and warps the head. You can usually do a full cooling system tune up for $100-$150

 

Super helpful info. Thank you a ton!