rough idle

I recently purchased a 1994 JGC Laredo with a 5.2L. V8. I have a few concerns.
1. It starts just fine, runs well, bu after I drive for awhile and put it into park, the idle speed constantly changes from about 600rpm to about 1100rpm. It is like it is surging sort of. We just replaced plugs, wires, cap, rotor, fuel filter and air filter just for maintenance purposes. It had this problem when I bought it. Any thoughts?

2. I recently noticed a sort of whining sound while in reverse. This does not happen in any other gear. The tranny fluid looks and feels very good.

3. I am smelling antifreeze after driving it for awhile and parking it. It has a new radiator in it. Am I smelling burn off or could there be another problem?

4.(This may sound stupid, but I don't have an owner's manual for it yet)
What is the deal with the sensor & switches on my rear-view mirror?

Please let me know what you guys think. I can't afford to take it to a mechanic yet. If it's something my fiance can fix, I would like to know. Thank you so much!

I recently purchased a 1994 JGC Laredo with a 5.2L. V8. I have a few concerns.
1. It starts just fine, runs well, bu after I drive for awhile and put it into park, the idle speed constantly changes from about 600rpm to about 1100rpm. It is like it is surging sort of. We just replaced plugs, wires, cap, rotor, fuel filter and air filter just for maintenance purposes. It had this problem when I bought it. Any thoughts?

2. I recently noticed a sort of whining sound while in reverse. This does not happen in any other gear. The tranny fluid looks and feels very good.

3. I am smelling antifreeze after driving it for awhile and parking it. It has a new radiator in it. Am I smelling burn off or could there be another problem?

4.(This may sound stupid, but I don't have an owner's manual for it yet)
What is the deal with the sensor & switches on my rear-view mirror?

Please let me know what you guys think. I can't afford to take it to a mechanic yet. If it's something my fiance can fix, I would like to know. Thank you so much!
It sounds like you may need to clean out the throttle body and particularly the IAC ass'y.
Check the passenger side floor under the mat to see if it is wet. Does the heater still work well, and no loss of coolant? Could be your heater core has gone out.
I wish I could speak to Questions 2 and 4 but that's something I would like to know for myself also.

2. I recently noticed a sort of whining sound while in reverse. This does not happen in any other gear. The tranny fluid looks and feels very good.


4.(This may sound stupid, but I don't have an owner's manual for it yet)
What is the deal with the sensor & switches on my rear-view mirror?


Not sure about your year but on WJs (99 and up) the auto dimming mirror has a front and rear facing light sensor.

There is a TSB about a whining sound while in reverse, but only for the 42re trans '99 and up and only when cold .
It may help to give you some insight though. --
====
210899 - BUZZ, WHINING, OR MOANING LIKE NOISE FROM COLD TRANSMISSION (REVERSE GEAR)
Date: 04/30/99

Model year(s): 1999 - 2004

Description: Vehicles exhibiting buzz, whining, or moaning like noise from cold transmission when reverse gear is selected.

Details: Some vehicles may exhibit an intermittent noise from the transmission when reverse gear is selected. This noise has been described as a "buzz", whining", or "moaning" like noise. The noise is most noticeable when transmission fluid temperature is below 38 C. (100 F.). The condition is caused by a resonance of the transmission regulator valve system.

Other items may cause regulator valve resonance, including air ingestion into the valve body or out of specification parts. These two items may be the result a possible cracked pump housing, a torn pump gasket, an under filled transmission, a restricted fluid filter or cooler flow, or an out of specification valve and/or valve body.

surging (idle up and down) bad throttle Position sensor.

Switches on the mirror are dimmer switches like mentioned above. It dims headlights from cars behind you so you don't get blinded by the reflection in the mirror.

Whining sound - check tranny fluid level (in nuetral, with engine at normal operating tempature). Might even want to change tranny fluid and filter.

Coolant smell, could be a bad Water Pump - there is a weep hole on the bottom - it leaks whenever the bearing goes bad, this tells you that it's bad and time to replace. Probably leaking and burning off on the engine.

OK, I have a '94 JGC Limited and have the surging as well. Started out with just doing the rough idle though but as of last night it got to the point of it surging while driving a long.
I have replaced all the sensors trying to get this problem solved except for the MAP sensor, crank sensor and cam sensor. I also did a very through cleaning of the IAC port on the intake before replacing the new IAC sensor and also cleaned the intake. These all seemed to help out but only for a short while and then my problem returns. I have a check engine light come on once in a while but not all the time. I have checked the codes with the my scanner/reader and it comes with with code 52, at the moment I can't remember what that means. That was made me replace the O2 sensor, thinking it was causing the rich mixture in the fuel, can definitely smell it running rich.
I am at wits end with this problem. I had thought maybe it could be something as simple as a plug wire being bad or a spark plug not firing correctly but a person told me if it was not firing at the plugs the computer should send an error code and the check engine light should come on, is that true? I did see a code for something like that in my manual but only for certain plugs, not for each one.
I also thought it may be a vacuum leak but can not hear any and have sprayed some WD40 around and nothing happened to the engine. I also used a piece of fuel line to my ear to help me detect leaks. Nothing.
I also have checked all the sensors with a digital multimeter as described in the manual and they are all testing OK, at least the ones I can test that is.

Replace the Idile Air Control valve. Cleaning them works some times, for a wile. It seams like I utlimatily end-up replacing the valve. I do two or three a year at my shop.