Informal poll of 5.3 engine.

[Z71GUY]

When your truck is completely warmed up (normal temp) where does it idle when in gear and park?  Mine seems to be a bit low.  Right at 500 or maybe a tad below (est ~480).  Sometimes at night when I put it into gear, my idle will drop around 450 (the lights will dim every so slightly, then it picks right back up to around 500)  Seems a bit odd...  This is not something that happened over night...just started to pay attention to it though...

 

 

If mine is shown to be low, what controls the idle directly?

[Redapple]

I idle about 950 in Park or Neutral, and about 550 in Drive

As far as how to ajust Idle... Don't Know

 

Bill

[RyanbabZ71]

500

 

1k When it is cold and then when the truck warms up it idles at 500

 

500 is normal

[cowboy02]

Right about 5 -550 when she's warmed up...

 

However she sounds like she is going to a fire when she;s cold.  can back out of the garage at 5MPH and never touch the gas

[Tucson_02Silverado]

500-550

[Shaners]

The 6.0L small block is about the same...  550 RPM when warm.

[Markeaux]

You really need to put it on an OBDII scanner for an accurate reading.

[99silveradoz71]

Not sure warm really, but I know she's at 1000 when cold, then seems to drop to 8-900 after about 30 secs or so of warming up.

[BlueRado]

My '99 5.3 was consistently at 500 warm in park or in gear, but the '03 5.3 is consistently at 600 warm.  Immediately on cold start, it goes right to ~ 1500 then slowly settles down to 800-900 in 1 min.

 

Like Markeaux posted earlier, you need to hook it up to get a really accurate measure, however.

[2000 GMC]

About 500

[TarheelZ]

The 6.0L small block is about the same...

Same for the 4.8L.

[cyrylyn]

You really need to put it on an OBDII scanner for an accurate reading.

going through the computer (and possibly malfunctioning sensors) is not as accurate as a tachometer - with a digital handheld tach you can point it at any rotating object and find the RPM.

[chvythndr]

Ditto on 500

[chvythndr]

Ditto on 500

[toddgotfish]

mine is 500 on the money when warm

but no light dimming problem

my problem was a slightly rough idle

i ran a can of slick 50 fuel sys treatment through it(10.00)

then i took out the IAC valve(idle air control)which is held in by 2 torx 20 screws right above the TPS sensor

after you get it out (i bet it's dirty)take a can of carb cleaner and really clean it good

CAUTION do not push on the pintle (tip)

squirt a little into the hole as well

put IAC back in reconnect wiring conn. turn the ign on for 10 seconds then off for 5

turn the ignition back on and crank truck

it's much easier than it sounds took me all of 10 minutes

e-mail me with any questions Todd :thumb: