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RPM's randomly drop while idling, no check engine light

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Old 09-20-2013, 09:59 AM
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Default RPM's randomly drop while idling, no check engine light

I have an 02 ram 4.7, Im always up on maintenance with it. Throttle body was cleaned last summer, has new plugs maybe 2000 miles on them, they are the correct plug and gapped properly. O2 sensors are maybe 15k miles old. The truck has 107k miles on it and always runs fine. This had only happened twice so far, I was sitting at a red light both times and the RPM's drop to 400 or so, the truck shakes a little and idle goes back to normal without hitting the gas. I'm gonna clean the throttle body again just to be safe. Any other suggestions? I need to fix this before it gets worse.
 
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Old 09-20-2013, 11:22 AM
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I assume you clean the IAC too. If it happens only after coming to a stop at a light then maybe the IAC is sometimes getting stuck a little.
 
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Old 09-20-2013, 11:44 AM
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I did clean the IAC before but Ill probably do it again this weekend. It doesnt happen immediately, it was well after the truck already had a steady idle.
 
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Old 09-20-2013, 04:21 PM
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I think cleaning is probably about all you can do for now. Going to be quite hard to track down if it does not happen more consistently. I looked at the service manual for low idle codes but cleaning the throttle body is about the only thing I see that you can do with being able to reproduce the problem more consistently. I don't know much about the 4.7. Good luck with it hopefully it will not leave you stranded with it gets worse which it probably will.
 
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Old 09-20-2013, 05:51 PM
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Ill tear into it tomorrow, it just did it again at a red light. I revved out first gear shortly after and it felt fine.
 
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Old 09-21-2013, 11:40 AM
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Check with your dealer too. See if there is some sort of tech bulletin out on this issue. Perhaps a new software flash available to correct it. Just a thought.
 
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Old 12-04-2013, 09:47 AM
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The problem has been happening for a couple months now, it only happens when the engine is warm and when the truck has been idling for more than 30 seconds or so. It only happens in drive at a red light, but not every red light, putting it in park while the idle is rough has no effect. The truck doesnt feel short on power and it isnt running rough anywhere else. I havent had a chance to clean the throttle body yet, but Im going to start there. Any suggestions on what else to look for while Im working on it? I plan on checking at least one spark plug.
 
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Old 12-04-2013, 09:58 AM
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what are you using to clean the IAT sensor?

Some cleaners can be harmful to the sensors.... you have to make sure it says safe for use on IAT sensors and/or MAF Sensors... (I know we don't have MAF sensors on our trucks, but rule of thumb is if it is safe for MAF it's safe for IAT)
 
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Old 12-04-2013, 10:20 AM
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Just a can of throttle body/carb cleaner, I guess I need to check and see if its safe to use on electrical parts.
 
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Old 01-20-2014, 11:44 PM
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Well I've been driving the truck quite a bit and I think the problem has almost gone away. I've been towing a good amount and doing a little snow drifting. I havent been easy on the truck but I cant believe how good the thing is holding up. If it continues to run this good I'm gonna wait until its warmer and give it all the maintenance it needs.
 



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