Idle problems

I think there may have been a thread on this before but I never found a good answer. Since last winter my truck( fze-fe auto) has been idling in drive/ reverse at around 588-600rpm. It seems to run pretty well from I'm told. No check engine lights/ codes either. Anyways, I was recently checking the engine out and saw oil coming out of a bolt fastening a wire on the back of the valve cover. I tightened the bolt and am wondering if that's relatively normal. It also makes a quietish deep tap in drive / reverse but not in neutral or park. Any help counts

Sorry for the word salad, just concerned.

 

Mine has a low idle as well. After a cold start the idle will fall below 1k

 

I mean true, but is 588-600 below normal? Will idling at that speed wear on the engine?

 

Possible IAC valve. Definitely need to clean the throttle body. Easy to do. It's just time consuming taking all the peripherals off to get to it. Also, could be the maf

 

Generally, when measuring idle, it's in Park (P) or Neutral (N). When the A/T is in gear with the truck at a standstill (brakes applied), the RPMs will drop down below idle- this is normal. It's important to consider some other things as well- Is the truck up to operating temp (coolant temp ~180)? Is the AC, heater, or other system adding load to the engine?

550-800 rpm while in gear at a standstill sounds normal- It's not wearing anything.

 

factory specs for idle are 700 +- 50 so a range of 650-750

BUT that is after racing the engine at 2500 rpm for 90 seconds. FSM can help a lot in these troubleshooting phases.

so, if you have a live data reader like ultragauge or scan gauge, hook it up, make sure all accessories are off and that you have proper ignition timing, then see where your idle goes after racing the engine at 2500 rpm for 90 seconds.

IAC valve is usually the culprit. Beware of doing too much cleaning in the throttle body itself, you can expose worn areas that were plugged up with carbon and then have a super high idle to figure out (yes I did that)

Cleaning IAC is pretty straightforward.

 

FWIW my 03 with the MT and 2RZ-FE idles at about 690 after it’s warm. I had the IAC go bad once and it stuck at about 1700 rpm but it dropped back down after the stealership forced it.

 

As your torque convertor wears......it loses it slip at stop while in drive....
this alone will drag down your idle speed......shuttering....