What is considered high for idle hours? About a month ago I got my truck back from being worked to try and fix the knock. They said they reflashed the computer to erase the idle time. Well its back in for the same knocking. The dealer couldn't find anything loose in the upper end of the motor, so they plugged in the computer to see if it was throwing any codes. They pulled up the idle time and the computer indicated 30 hour of idle since my last visit, which was about a month ago. That's 1 hour of idle a day. I don't care what the computer says, there is no way! I drive about 80 miles a day round trip to and from work and I-75 and that's it. Anyhow, anyone else have this issue come up?

 

From what I have been told "Idle Time" is any time the engine is running below 1000 rpm. In city stop and go traffic that is a lot of the time.

My dealer told me that my "Idle Time" was way to high and that was part of my bad mpg. I do not let the truck idle but a minute or two when starting and turning off.

 

my gas mileage is good, 16-17MPG. i don't do city driving, but if idle is anything below 1000 RPM, then just taking you foot off the gas and coasting will an idle, then sitting in a traffic jam will be idle time, and so on.

 

Yep, same input from dealer and STAR after second injector found bad.

The Computer won't show a bad injector. They have to disconnect one (diconnect fuel line) at a time, and drive until warm to find out which one is bad. Then, they have to swap the bad one to another cylinder and repeat the process to make sure it's the injector and not an engine/piston knock.

Try running some Stanadyne Fuel additive thru the truck for a couple of fill-ups and see if it helps. I have had no more injector knock problems and mpg went up too.

 

Another one here as well, just like the fellows above.... I believe the Dealers have been instructed to use the "high" idle time as an excuse. I asked the service manager did DC build these trucks specifically for "highway use only" ?? He gave me one of those deer in the headlight looks.... ..amazing.

 

Ime rite there with ya on the high idle time thing. I have been fighting a knock for abought 10000 miles now and I took it in to have it checked out for the 3rd time and they said too much idle time. I had been told while making the apointment that they already suspected high idle time and hadent even looked at or heard the truck yet. That told me the story rite there. Star had created an excuse or loophole to get out of fixing a problem. I asked the same question, Did they build a truck that cant be driven or am I just suposed to never drive it unless I am towing a cement truck? They dident realy know how to respond. So anyhow when my wife and I where dropping it off at the dealer I told her on the way home that if they dident blame high idle time for causing carbon builup I would eat my truck. She laughed and said OK what ever. When I called inthe next day to check on it lo and behold what was the problem? To high of idle time causing carbon buildup. They removed the injectors and cleaned them and that did help some but they want me to tow with it more. They said if I cant tow with it to tromp on it more. So thats what I have been doing. Who would have thought a 7000 lb truck could slide the rear end around on dry pavment like that. Any how This high idle thing is realy starting to bug me. But hopefully my knock doesent get any worse. They only want it to idle for 2 or 3 minutes no matter how cold it is. I asked if that meant at 5 below 0 as well and they said yep 2-3 minutes and drop it in gear and go.

 

I have to call BS on the dealer on this one. I watched my tac on the way to work this morning. If you are moving the tac is above 1000rpm most of the time. Mine was above 1000 at 10 mph ***? Its just a lame excuse for them

 

THIS JUST IN...I spoke with the dealer this morning to find out more, they were going to talk to their tech and STAR yesterday afternoon. This is what they said. Not one mention of high idle from the tech or STAR, but they did say that I'm "not working" the truck and that I need to work it more to increase the combustion temp. I drive 75-80 MPH on the way to and on the way back from work each day. I've towed with it some, a 21 ft boat a couple of times and a John Deere tractor a couple of times. That's it. Could this be the cause of the knock? They suggested running some fuel additive to see if that helps. How would that help after they just got done telling me that I "need to work the truck more?" Anyone else get this same song and dance?

 

I just had the same thing happen. I went in 3 times before they changed two injectors for me and then warned me that I had high idle time (they said I had 40% which is bulls@#*) so this meant DC would not pay for it next time if it happened again.

I have never taken kindly to threats and ask the service manager to show me in the warranty where it showed I had to continually drive my truck up a never-ending hill while pulling a heavy trailer (all the hills I know have a down side and wouldn't that means your engine would be idling coming down. ). He said he agreed and that was just what Star told him to say.

I pointed out to him that I drove my 2nd gen the same way for over 300K miles and never had any problems with it. He didn't want to talk to me anymore after that.

I find it hard to believe that Cummins designed this engine only for a continuous heavy torque application. These 5.9L engines are in many commercial applications such as delivery trucks (I think they are in many UPS and Fed-Ex trucks) and I am real sure that they will be idling much more than I do. This is a screw-up and they don't want to pay for it.

I have 22K on my truck and think this is only going to get worse the older the truck gets. I can no longer recommend to people to buy this product. I am seriously considering selling this truck and buying different brand.

I never thought I would say that about a Cummins/Dodge truck.

 

Without getting into what BS the dealers are or aren't saying, I've noticed that if I don't get out on any long highway trips for a while, my truck will develop a bit of a knock and just generally be a bit rougher. A few hours at high highway speeds seems to help put everything back into order. Sometimes if I haven't been on the highway in a while and don't seem likely to any time soon, I'll just keep it in a lower gear and keeps the RPMs up on my around town trips.

Tad

 

I did not add in my post above the "High Idle" comment was made when I complained about low mileage and white smoke so they would do TSB 18-037-04.

The TSB changed nothing about my symptoms (rought idle, white smoke when there should not be any, ping and knock) that did not exist for the first 4 months.

Finally after leaving the truck overnight at the dealer to confirm all of my complaints they diagnosed a bad injector. Replaced #6 injector. Things are better, but not the way they should be yet.

This is my first diesel and I expected a lot more from a Cummins TD than I have experienced so far. I have 15000 miles now. If I was not so upside down on the note, I would probably consider trading now.

 

Stutz, my Dealer tried to pull the old ..."put a trailer behind it and work it hard" routine on me which is nothing short of pure hogwash. I tow at least weekly 10-12 K lbs and it may not be a huge load it certainly enough to "work" the engine.

GM tried the lame excuse route with me several years ago when the Silverado HD's came out mine (6.0 gasser) developed a horrible cold start knock, the dealer claimed that it was carbon build up due to excessive idle time. I took it in at least 5 times and they did everything and nothing worked, they even tried soaking the
cylinders with some type of cleaner overnight....carbon build up...not a chance.

 

I've noticed on my truck if I baby it for a while and then get on it (i.e. the "Italian tune-up) that there's a nice black cloud that comes out the back. Do this 1 or 2 more times and the cloud disappears completely. I believe that this is carbon buildup getting dissipated. I've noticed the same thing with many gas motors. Fact is, ANY motor needs to be worked hard now and then to get the cylinder temperatures and pressures high enough to clean the carbon out. Basically, I think these engines fall under the category of engine that do the best when you're hard on them. It would certainly not be the first engine that I've seen this happen on.

That said, the fact that this is happening is unexcusable, even moreso that DC/Cummins is just blaming the user. We have warranties, honor them!

But it does seem that most of the people who suffer these problems only drive their trucks locally. My truck has just over 13,000 miles on it now (will have about 20,000 by early March). I'll do city driving for 2 or 3 weeks at a time, and then go do long highway drives, usually with a car trailer + car attached for a weekend or few weeks.

Ultimately, I'll see in another 200-400,000 miles just what this engine is made of.

 

I think this problem is only going to get worse with the 600's (I hope I am wrong). I have almost 25,000 on my 4.5 and I don't "baby it". I drive it 60 miles a day round trip. I cross a fairly steep hill (1500 ft Elv. change) twice every day and hold a speed of better than 70mph. At least once every other week I pull a 8000lb trailer to work and back and about once a month I pull my 5th wheel trailer on a trip of better than 500 miles.

I grant you I am not pulling 15000 lb trailers around everyday but I would think that should not be classified as "not working my truck".

I am looking forward to seeing what happens as more people start to get 15,000+ miles on their truck. This is only the tip of the iceburg if you ask me. STAR won't be able to stick their heads in the sand much longer if that happens.

 

I have been unable to fins anything that says this truck has to be used to tow heavy loads or the warrenty is void...I am taking mine in Monday for the knock and I only have 3000miles on it. I am worried I am gonna hear this high idle time. I live in Northern VA and am in stop and go traffic about 60% of my driving time. I dont tow very often at all right now because it is to cold to fish (at least for me). I think a class action suit is in the future...I bought this truck because I drive 40,000 miles plus a year just to and from work. I wanted something that would last me more than 3years...I am not so sure I made a good decision now.