A strange symptom showed up on my truck the other day. After driving about 100 miles I pulled off the highway and noticed my truck was idling between 850-900 rpm. Normally it idles a touch under 800 rpm. I revved it a couple times before I shut down and it did not drop back to normal. I checked for codes and there were none. Any ideas?

 

Colder temps. I see your in Montana. I just looked on Weatherunderground and the avg temp for the state was 45*

 

This is not the typical cold idle-up, something else is going on.

 

How is your oil level? Is it on the rise...maybe a bad injector. Don't know, just thought I throw it out there.

Tony

 

I have been watching the oil level, so far no rise. But with all the other symptoms I am also leaning toward another bad injector. Or could it be related to the FCA or something with the IP?

I am headed back to the dealer this afternoon. My options are running out before I am forced to do something else with this truck.

 

Mine has done something similiar for a while. I'm pretty sure I could fix it with a new FCA but it doesn't bother me too much. I've heard of it fixing similiar issues for others on this site. Try stomping on the brake to see if that makes it idle down.

 

Bighorn, have you recently had any dealer work done to your truck? If so they may have flashed your truck. The flash raises the base idle to around 850 if I'm not mistaken. A guy on another forum had his truck flashed for something else and noticed the idle changed. He pushed them and they told him that was in the flash they had done. He also had this confirmed with DC. BTW, he wanted it back to 750 and they (DC) will not do it.

 

My very first flash almost a year ago raised the idle from 700 up to 800. I did have some recent work done which included a #3 rocker assembly (with tappet and pushrod) and new ECM and #4 injector. But this is not a consistent high idle, this is something that only happens once a week or so, usually after being on the highway for an extended time. I have also had a lot of trouble with rough running and low power/surging when hot.

At any rate, I had a long talk with the service manager today during my oil change. I have had my truck exactly a year today, and it has been in the shop 8 times and 27 days. Because of all the problems I have been having, they are going to replace the remaining injectors (2,3,5,6). He said they have had a lot more trouble with the 04.5+ CR injectors, even has been dealing with his own truck problems lately.

So we will see what happens, I am crossing my fingers that this finally brings an end to this mess.

 

I'm curious, what caused them to replace #3 rocker assembly? Mine sounds like it has a valve tick sometimes. I had #6 injector done because it was leaking down overnight. It runs fine now so I don't want them to tear into it any more than needed. But the tick worries me sometimes.

 

The rocker arm broke, taking the pushrod and tappet with it. It was right after they did a bunch of work so I am guessing it was reinstalled wrong.