idle drops when put in gear

[whiterider00]

now i dont know if this is a major problem, or just something that happens with age and milage, but when i start my car, if i immediatly put it into gear without letting the rpms even out, it just about stalls. rpms will go down to a couple hundred, lights will dim and the engine will stutter for maybe a half second, then itll go right back to normal. i always try to let the rpms even out and let the engine warm up at least a little bit before putting it into gear, but occasionally when i dont thats what happens. just curious what could be the cause and if its anything to worry about. thanks.

[01silveralero]

let me see if I read this correctly:
Rpm starts high (thats normal for all GM's) "they" think they have to always warm up regardless warm or cold start.
When put into gear the rpms drop some usually after the torque converter is engaged.
Lights diming could be a couple of different problems. (lets hope not an alternator problem but you didnt say gauge problem so probably battery or electrical problem)
Engine stutter could possibly have a cylinder trying to misfire. (possible coil or idi problem) this also could be a vacuum problem that is just starting to happen.


FYI: my idle on my 4 cylinder goes from like 750 to barely above 500 when is warmed up.

[Nate's Alero]

um, let it warm up? let it sit for at LEAST 30 seconds... it's SO bad to just jump in, and immediately put into D...

if you're really concerned, it's your IACV... it's slow and worn out

[Th0r]

Mine jumps to 1000 on a cold start and then drops to around 650 when put in gear.

[Nate's Alero]

but his drops until it almost dies

[RockfordAlero]

while on the topic, why would my car idle at 2000 constantly... its fixed now, i drift started it one day, blew abuncha black smoke and now i idle at 1000

[whiterider00]

um, let it warm up? let it sit for at LEAST 30 seconds... it's SO bad to just jump in, and immediately put into D...

if you're really concerned, it's your IACV... it's slow and worn out

ya, thats what i do when i can. occasionally i have to move the car really quick so someone else can get out or something like that and i dont feel like pissing them off by making them wait. and what does IACV stand for?

[[ion] C2]

idle air control valve

[Nate's Alero]

and yeah, 100% that issue.. it compensates for the butterfly valve being completely shut, so the car can idle... also helps with coldstarting

[whiterider00]

ok thanks. ill check it out.

[a.graham52]

your lights going dim could just be becuase of the low rpms. my lights dim a bit at idle all the time. give it just a hair of gas and the lights brighten up.