Idle Bounce question

[Winston Wolf]

Been noticing something on my '05. When I'm coming to a stop and slip it out of gear, the idle drops, bounces a few times between 600 and 750 RPM or so, and then settles in for a rock solid idle at 750. I'm seeing 2, 3, or sometimes 4 bounces before the idle settles.



I'm not necessarily too concerned about this. But it does seem a little quirky.



Is this "normal"?

 

[RLutkenhaus]

I have a 2004. 5 with 6 speed that does the same thing. Don't know why it does it but would like to fix it. I've heard the the fuel mileage/white smoke TSB fixes this problem. Currently I don't have a problem with either of them, no white smoke and fuel mileage is 20 mpg @ 60 mph, 19. 5 mpg @ 65 mpg, 19 mpg @ 68 mph, 18. 2 mpg @ 70 mph, 17. 8 mpg at 75 mph.



2004. 5 2500 QC, SWB, 2WD, 6 speed, 5000 miles.



Robert

 

[Winston Wolf]

Interesting. My engine, however, is "newer" than the serial number range specified in the TSB. Doubt that mine would be eligible.



Still on my very first full tank of fuel. Looks like it will be 15-16MPG.

 

[wyosteve]

If memory serves me correctly, this was brought up about a year ago. Seems like someone said it's associated with the rail pressure changing. Seems to be normal so I wouldn't worry about it.

 

[chi440]

It does the same here - Oo. - I consider it to be 'normal' with this system - unless I hear otherwise... .



Only on 3rd tank here...

 

[DIESELMAN]

My '03 didn't do this in the slightest, but my '04. 5 oscillates above and below the idle speed several times. It also does this after using the Power Pup downloader on any level.

 

[nickleinonen]

my 04 does that if i toss it in neutral and coast. heck, my 03 4. 7 gasser did the same thing... i think the ecm is trying to figure out if the truck is in gear or not with the manual trans trucks... i consider it normal and it doesn't bother me in the least

 

[rashwor]

My '05 that I picked up last night does the same thing. It was unloaded off the delivery truck Monday afternoon.



As long as the truck does not die when it does it and it goes back to the correct idle, I will consider it a non-issue and the nature of the beast.

 

[jelag]

Remember guys... the ECM on the truck has to learn the truck and the operating conditions it runs under... . and it takes some time to bulid those logs... .



I picked up my 05 2 1/2 weeks ago... pulled it into the garage and there it sits ... with 30 miles on it... . Some of the accessories are starting to come in... .



Jim

 

[mberry]

Mine does it too. Doesn't bother me at all so I don't really pay attention to it anymore. It does do it a bit worse when the A/C is on.

 

[CoastyAV8R]

My 04. 5 does it also. I don't think the ECM is going to learn how to control this as mine has 10,000 miles on it and still does it the same way it did the day I drove it off the lot. I've had the 18-037-004 TSB and it still does it. I know my 01 HO 6 speed didn't do this and neither did my 91 Cummins so this isn't normal when compared to the manual transmission's from previous years. It may be normal for the HPCR motors, but nobody has told me that yet. I personally don't consider a fluctuating idle normal. Does it bug me much? Not really. It does bug me the most when the AC is on and it's more pronounced. I would like to get it fixed to the point it doesn't do it anymore but I'm not getting rid of the truck for it, the truck is great...