Odd Idle when at operating temp.

[Bumpin' Yota]

Ok no mods save the kitty delete and has NOT been reflashed by ford since we drove it off of the lot.

When warmed up, in gear, and waiting at a light, if you listen to the idle, the "knockyness" to it seems to rythmically change.

It sounds like the computer is advancing the ignition timing (making the engine sound like a trainwreck) for a few seconds, then backs the timing out (making the engine run much quieter), and slowly shifts back and fourth repeatedly. I dont know if the pcm is messing with the timing or not, but the noise is driving me whacky.

what the hell is going on?

[DoubleDpsd]

bad fuel ?

[Bumpin' Yota]

definate no. The PSD has done it no matter where we fuel up. And the place we fill up has a high turnover rate of diesel and has always had great oil to burn... Both the 6.5LTD and ISB have no issues with this place's diesel.

[mschn99]

i would say either your fuel filters are plugged (should be changed every 15k) or your EGR valve or turbo are carboned up...that would be the most likely causes...

[sldghamr]

mine did something similar, then i started run 20% Biodiesel. straightened out things real quick

[Bumpin' Yota]

if the egr is carboned up what should I do, somehow clean it? What about the turbo? Fuel filters were changed about 8k back or so.

No biodiesel here unfortunately.

[mrnecsteve]

Time to get out the ole timing light??? Just kiddin....
check this out
FDDTS - 6.0L EGR Valve Cleaning

[Bumpin' Yota]

Bringing this back...

Its got WAY WAY worse!!

New Fuel Filters
Cleaned EGR
4" turboback MBRP exhuast
Pulled battery terminals for 20 min


Now it does it so bad that you can hear the turbo spool up and down at idle. Oh and when you set the cruise control you can watch the boost fluctuated by 3 psi or so every 4 to 5 seconds.

What gives? Is my turbo going to grenade directly?

[bigcountrysg]

Is there a cps sensor on the 6.0L I am just asking I don't know if there is or not. I would think there is, if so could that cause this problem.

[rednek01]

Originally Posted by Bumpin' Yota

Bringing this back...

Its got WAY WAY worse!!

New Fuel Filters
Cleaned EGR
4" turboback MBRP exhuast
Pulled battery terminals for 20 min


Now it does it so bad that you can hear the turbo spool up and down at idle. Oh and when you set the cruise control you can watch the boost fluctuated by 3 psi or so every 4 to 5 seconds.

What gives? Is my turbo going to grenade directly?

Mine does that every once in a while I'l going to clean my turbo and egr this weekend I had taken the turbo off before but didnt know how to clean it but it was caked up pretty good I'm thinking cleaning it will make it feel like a whole new truck!