gscoker

It's been cold here on the east coast and I have been driving my truck a lot and I have noticed a change in behavior of the automatic high idle. The high idle lopes in the same way as many others have reported and captured on YouTube. Sometimes the loping is more pronounced than others. I have an 05 with 91k on the odometer. I am concerned because I haven't heard this before and my father-in-laws 04.5 is smooth on the automatic high idle. The troubling part is my efforts to search have been inconclusive. Half say its normal and half say its an injector issue. I've even seen someone report that changing the injectors made no difference.

Otherwise, I seem to have a solid idle at 750 rpm and fuel economy is still reasonable. I have run powerservice through a couple of tanks but it made no difference.

So I am wondering, do I service the injectors? I'm thinking of doing the service myself since I don't have a good local independent and I'm betting the dealer will be $1k per injector ( if you think the dealer would be less please let me know). At 90k have I pretty much gotten all the life I should expect out of the stock injectors? This would be disappointing but I have also read that Bosch redesigned the injector components in 2009 due to premature wear. I would appreciate a recommendation for where to get good stock injectors. Are remains ok? Looking for advice, thanks!

47Dodge

I just bought my 2005 in october. I have experienced the lumpy idle. Its the cold weather 3 cylinder idle mode. Truck kicks up to 1000rpms and sounds a tad different and a slight shake. After a few minutes it drops to normal 750 idle and then will idle back up. My truck has the manual high idle added to it via the cruise control. I wonder if having that mod also does the lumpy idle as well. Some trucks do it and some dont. Some say the 3rd gens dont do it and others say they do......

What I have noticed with my 2005 is a cold start in the morning will sometimes if cold enough out side will go to high idle 1000rpms. Smooth 1000rpm high idle to warm things up.

When its really cold after the truck has been running a while and then left to idle it will go into the 3 cylinder lumpy idle mode. What I have noticed on the lumpy mode its not really depending on engine temperature but seems to be using outside air temp to put it into lumpy mode. I have had the truck 2/3 or more running temperature. Stop for a few minutes and left it idle and after 2 minutes or so it goes into lumpy. It only will do lumpy when its cold cold outside. I think maybe 20 or so degrees is the area in which mine will do it. At no time has it did lumpy on a cold start in the morning only the smooth 1000 high idle.

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gscoker

I should add that the truck has been parked outside and we've been having lowes in the single digits and highs only in the teens or low twenties. So it is certainly below 20F when I've been heading out to go to work. I've also been plugging it in at night which didn't make any difference on the lovey high idle.

47Dodge

Its normal............doing what its supposed to be doing. Like I said the lumpy 3 cyl mode doesnt seem to really care about engine temp but only goes into lumpy mode when the outside air temp is cold cold.........they say the 3 cyl mode makes the engine work harder to idle and generates more heat to stay warm then all 6 cylinders firing...........

I have found no cut and dried official info on the internet describing the process of the 3 cylinder idle and the in's and out's and why's of its operation. Only what I have experienced and from talking to others.


47