jrbudman

Okay, new problem with my '03 CL-S MT. Hopped in for my usual morning drive to work & about 1/4 mile down the road, when I put it in neutral, the engine surges up & down from normal idle up to about 3500-4000 rpm. I didn't notice anything while it was in gear, only in neutral, but I just turned right back around & parked it. I haven't had a chance to do any diagnostics yet but if anyone has a suggestion where to start looking, that would be greatly appreciated. Thanks all!

gnuts

iTrader: (1)

it's probably your IACV. It's on your throttle body and it gets clogged up over time and won't open and shut properly. Tell tale is that on the gas it's fine and in neutral the revs bounce on their own.

thoiboi

IACV typically. or clean your throttle body. else there is a vacuum leak

jrbudman

yeah, my first guess was a vacuum leak but I'll take a look at the IACV. Thanks a ton!

thoiboi

Karanx7

iTrader: (2)

Sounds like an IACV issue to me. You should spray some water around the intake manifold just to be sure it's not a simpler vacuum leak.

For the IACV, you can try cleaning it. Unfortunately, this doesn't always work, and you might have to buy a new/used one.

jrbudman

Yep, it was the IACV. Took it all apart & cleaned it up, easy fix. Runs like a champ now
Thanks for all the help. You guys are awesome!

thoiboi

thanks for the follow up!