I have a '07 Grand Cherokee with a stock Hemi. Sometimes at idle the RPM's will stumble and almost shut off. I just swapped the air filter to a K&N and pulled a couple of spark plugs to check them out. They look healthy. What could be the issue?

If this was the Belvedere there wouldn't be any question. But then the Belvedere doesn't have variable valve timing, multiple displacement, mpfi and all that other stuff.

Suggest taking it to a dealewr and have them hook it up to their disgnostic computer. They'll catch any codes. Also, for around $80 they can upload the latest software.

I had a similar problem with an '06 MDS hemi. It wasn't showing any codes and the new software seems to have fixed it.

Have someone test the battery. Every time a battery starts to get weak, engine acts weird.

Not sure if this will pertain to your 5.7 Hemi, but my 4.7 in my Dakota was doing the exact same thing. I finally located the idle air control valve (with much help from members here, thank you very much), pulled it and cleaned it along with the throttle body. So far, no more stumbling idle problems!

Good luck! It seems to have solved that exact same issue with my Dakota. I used some throttle body cleaner, and was quite liberal with it inside the throttle body, as well as all over the iac valve itself. The engine didn't want to run at first, I'm assuming due to the amount of cleaner that I used. But it did finally start, and has (so far) been clear of the stumbling at idle.

Keep us posted!

Hey, how did the repair attempt go???

Worked like a charm. Though I forgot to hook the MAF sensor back up and got a check engine light... All is well now. It idles happy.

GREAT ADVISE!

There is no IAC on a hemi. Could need a computer flashed, but dealer will know that by VIN.

I would be very surprised if that much carbon/deposits have built up on the throttle blade needing it cleaned. Its worth a shot though.

Justin

The check ENG light went out as soon as I reconected the MAF.

As for deposits on the throttle body, it looked like it had 75,000 miles not 25,000. It was thick! Now its all clean and the Hemi is Happy.

Good to hear!!! Glad we could help!