6.4 idling at 770-800 rpms WTF

Cory S · Jul 17, 2012

So it just started doing this sometimes any clue what it could be? And also I am getting a sound like an egr valve cycling but have to egr. And no change in exhaust note.

Mpoage · Jul 17, 2012

Do you run an SCT and did one of your exhaust sensors come unplugged?

Cory S · Jul 17, 2012

Yea run sct with gear head and idp tunes all exhaust sensors are plugged in and reading.

Mpoage · Jul 17, 2012

What about the pressure sensor. You might crawl under there and make sure its still plugged in.

Cory S · Jul 17, 2012

i will do that

BFT · Jul 18, 2012

Do you mean it will go up in RPM if you tap the throttle? I get that sometimes, seems like its in regen or something along those lines, right?
Another thing on the cycling noise, if you have the A/C on it will make that noise, just an FYI

drunk on diesel · Jul 18, 2012

the one that always freaks me out is you give it some throttle to back up and it kinda hangs for a bit. Only happened to me about ten times but it freaks me out every time

SEABEE08FX4 · Jul 18, 2012

Check your air intake boots and make sure they are tight and not loose. That will make it idle weird or low, a bad or unhooked DPF sensor will make it idle high like around 1000.

Pjmobb · Aug 19, 2021

I have the exact same thing happening with my truck. I know this is an old thread. Just hoping to get some info before I take it to the "stealership". What did you find out? Mine is intermittent. I can turn it off start it back up and sometimes I am good for a day or 5min. Idles about 650-680 and when it's screwing up it idles about 750-800rpm.