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Discussion Starter #1
Hey guys,

I have a quick question. My car idles at around 550 RPM when at a stop with the gear in D. Is this normal? I have noticed that it happens more often when I have the AC off. I have had some idling issues in the past where the RPM would stay at around 1500 but were fixed when my dealer changed my throttle body. I have noticed that the 550 RPM idling happens when I'm at a stop and would go back to normal once I change into N and back to D while at the same stop. Is this normal?

I'd appreciate your feedback.

Thanks,

Fawaz
 

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Also...I think the auto has something that cuts cylinders when they are not needed to help it conserve fuel..as I said...im no expert but thats something you can google to maybe help u answer your question. ..also...if it really just annoys you...buy a diablo trinity tuner, wich, with your auto, you will want anyways....I think it has an option to change your idle rpm to what u want it to be! Hope this helps. I just got my trinity yesterday and I absolutely love the adjustments u can make.

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I have a quick question. My car idles at around 550 RPM when at a stop with the gear in D. Is this normal? I have noticed that it happens more often when I have the AC off. I have had some idling issues in the past where the RPM would stay at around 1500 but were fixed when my dealer changed my throttle body. I have noticed that the 550 RPM idling happens when I'm at a stop and would go back to normal once I change into N and back to D while at the same stop. Is this normal?
Your post is very confusing. Please be more specific with RPMs instead of "normal". 550 RPM in D is about correct. 1,500 RPM idle is way too fast in N let alone D. From what I understand the MDS only kicks in at highway speeds.

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Maybe he got it fixed?...I dont know much about mds...I have a m6. Ya.. I saw that 1500 rpm and I was confused too....I think thats what he said the shop fixed..and now hes paranoud its too low?

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Discussion Starter #6 (Edited)
Sorry guys if my post was a bit confusing. I was posting this thread through my phone earlier today. What I actually meant is that I had an issue with my car's idling where the RPM would stay at about 1500 RPM and I would have to turn the car off and start it again in order for it get back to around 750. In addition to this, I also told the dealer that my car revs too low (at around 550 RPM) and they said that this is not normal. My dealer changed the throttle body on my car and the 1500 RPM idling problem disappeared. So that has been already dealt with a couple of months ago.

My question is: Do auto R/Ts normally rev at 550 RPM at a stop in D? This rarely happened before but keeps on happening now more often. I can feel the car idling a little bit rough when the RPM is dropping to around 550 RPM. I also noticed that if I shift into N and back to D at the same stop, the RPM will go back to around 750 RPM (This is what I meant earlier by normal).

I just want to know if these cars normally rev at 550 RPM. I honestly don't think my dealer knows as much as they think they do when it comes to Challengers. This is based on my past experience with them.

I would appreciate any feedback guys.

EDIT: I forgot to add that this is definitely not related to MDS because it does not activate when the car is idling.
 

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Discussion Starter #7
Maybe he got it fixed?...I dont know much about mds...I have a m6. Ya.. I saw that 1500 rpm and I was confused too....I think thats what he said the shop fixed..and now hes paranoud its too low?

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Exactly!
 

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Discussion Starter #10 (Edited)
Is it idling rough at 550? Feel like theres a miss, or is it still smooth?

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I do feel a slight roughness while its idling, not that I would consider it a misfire but it's definitely not as smooth as when its idling at 750 RPM. I feel it mostly when the RPM starts to drop to the 540-550 RPM range. It happens randomly though.
 

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Discussion Starter #11

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I'll check mine in a little while for you. my car has 1800 miles only and is smooth as silk in gear
at red lights. I noticed when cold the RPMs are somewhere near 1500 for 30 secs, then drops to just near
900-1000 rpms in N or P.... in gear it's probably about 600 rpms but not sure. I know mines running right
and wouldn't change a thing, I'll check the RPMs here later and tell you what it is.
 

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If I'm coasting in neutral, the rpm will drop down to about 550, then bump back up to 750, over and over, but just sitting still it stays at 750 or so...
 

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Discussion Starter #14
I'll check mine in a little while for you. my car has 1800 miles only and is smooth as silk in gear
at red lights. I noticed when cold the RPMs are somewhere near 1500 for 30 secs, then drops to just near
900-1000 rpms in N or P.... in gear it's probably about 600 rpms but not sure. I know mines running right
and wouldn't change a thing, I'll check the RPMs here later and tell you what it is.
Thank you, I really appreciate it!

If I'm coasting in neutral, the rpm will drop down to about 550, then bump back up to 750, over and over, but just sitting still it stays at 750 or so...
That is how it should idle normally, but what mine does is drop the RPM to around 550 when the car is in D only and stays at 550 until I accelerate or switch to N and back to D (then it goes back to 750 RPM). This happens when the car is at a complete stop.
 

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Fawaz,

I checked out the idle speeds so I could say for sure.

cold start in Park the engine idled at 1350 RPMS for about 45 seconds then the RPMs
dropped to about 1000 for another 30 seconds. another 30-40 seconds later the idle dropped
again to about 800 RPMs. in park and neutral 800 RPMs is as low as it idled and was very consistent.
when I dropped the shifter into Drive from Neutral the RPMs only dropped to 750.. I alternated between
Park, Neutral, then the Drive several times and the RPM's never dropped below 750 in gear, or any lower
than 800 out of gear (Park or Neutral) fully warmed engine, 35 degrees ambient temperature. air conditioning
and defroster set to the OFF position.

from what I saw tonight with my car, 550 RPMs seems low while your car is in gear. (Automatic transmission)

hope this helps, you may still have an issue or a problem there. anything I can do, just ask.

good luck,
 

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my 2012 R/T has been doing this since it was new if you read the manual rpms should be at 650 no less at idle when hot in D...

I think it could be a few things: I was watching 2 guys episode about a month ago and they had a guy talking about the boots on the spark plugs which happen to be very cheap and lose with only a spring like connection.. he recommended the boots he was demonstrating to fit and snap into the plug very tight, he also said a bad connection can cause a misfire and less power to the plugs! logically this sounds about right to me i have forgotten about it until you posted this thread lol.. I need to find this link which i had saved...

This was strictly for Dodge hemi engines!!!!
 

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Discussion Starter #17 (Edited)
Fawaz,

I checked out the idle speeds so I could say for sure.

cold start in Park the engine idled at 1350 RPMS for about 45 seconds then the RPMs
dropped to about 1000 for another 30 seconds. another 30-40 seconds later the idle dropped
again to about 800 RPMs. in park and neutral 800 RPMs is as low as it idled and was very consistent.
when I dropped the shifter into Drive from Neutral the RPMs only dropped to 750.. I alternated between
Park, Neutral, then the Drive several times and the RPM's never dropped below 750 in gear, or any lower
than 800 out of gear (Park or Neutral) fully warmed engine, 35 degrees ambient temperature. air conditioning
and defroster set to the OFF position.

from what I saw tonight with my car, 550 RPMs seems low while your car is in gear. (Automatic transmission)

hope this helps, you may still have an issue or a problem there. anything I can do, just ask.

good luck,
Thank you! Much appreciated brother! My car has been doing this ever since I bought it and my dealer poured in fuel injector cleaner, changed the fuel pump (both done at around 3k miles), a new throttle body (at around 6k miles) for the same issue and countless "updates" and "programming" done by them. It has been to the dealer about 11 times in the past 7 months for this. I just hope I have this solved this week when I take my car in for a small issue with my transmission.

Once again, I appreciate your efforts Diver88! Thanks!

my 2012 R/T has been doing this since it was new if you read the manual rpms should be at 650 no less at idle when hot in D...

I think it could be a few things: I was watching 2 guys episode about a month ago and they had a guy talking about the boots on the spark plugs which happen to be very cheap and lose with only a spring like connection.. he recommended the boots he was demonstrating to fit and snap into the plug very tight, he also said a bad connection can cause a misfire and less power to the plugs! logically this sounds about right to me i have forgotten about it until you posted this thread lol.. I need to find this link which i had saved...

This was strictly for Dodge hemi engines!!!!
As I mentioned above in this same post. I've had fuel injector cleaner poured in my car when it was new, a new throttle body and fuel pump. This was all done within the first three months that I bought it. I have also had countless updates and programming by the dealer. Honestly, I googled it and found nothing on Challenger but did find some threads on Charger forums and some members stated that Chargers normally idle at around 520-600 RPM so I thought this could be normal on Challengers too (but the Chargers mentioned were the older 5.7's)
 

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Aren't things like idle speed controlled by computer? I mean if you can adjust the idle speed with a Trinity tune, that must be the case. Also when you stop to consider that this is an issue with different cars/same engine wouldn't it make sense that there were some of these computers with bugs that wound up in different cars with the 5.7?

Sorry for using the generic term for the particular computer... would that be the ECM? I don't know.

Regardless it would be interesting to see if the problem went away if you replaced the ECM, but getting the dealer to agree to such an expensive solution to such a "minor" problem is going to be a trick.
 

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Discussion Starter #19
Aren't things like idle speed controlled by computer? I mean if you can adjust the idle speed with a Trinity tune, that must be the case. Also when you stop to consider that this is an issue with different cars/same engine wouldn't it make sense that there were some of these computers with bugs that wound up in different cars with the 5.7?

Sorry for using the generic term for the particular computer... would that be the ECM? I don't know.

Regardless it would be interesting to see if the problem went away if you replaced the ECM, but getting the dealer to agree to such an expensive solution to such a "minor" problem is going to be a trick.
I have a strong feeling that this is something to do with the PCM. The thing is, R/T Challengers were only sold in Bahrain for one month for some reason (which is when I got mine). We don't usually get R/T's. It's either a base SE or a fully loaded SRT. This is why my dealer is not really familiar with R/T's and do not know what's going on with the car. We have only two dealers here and this is the same case with both of them. A tuner is not really an option for me because of warranty reasons.

I will try my best with the dealer when I take it in this week, I just hope this gets solved because it is getting really frustrating.

For some reason, I keep on experiencing issues with my car but I keep on loving it more and more every day! I'll never consider selling it!
 

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PCM, thanks! I'm not familiar with this Dodge stuff.
 
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