very rough idle [Archive] - Dodge Charger Forums

: very rough idle


daghostmon
02-24-2007, 09:48 PM
My RT gets a very rough idle intermittently but very often when warm and the ac is running. I'm talking so rough that my wifes tits are a bouncing up and down.:lol: Took it to small town **** hole dodge thats close to work and of coarse they could not duplicate problem even though it was doing it 2 min after I left the dealer. They told me they scaned it and even checked fuel pressure. Anyone had this problem? I need to fix this so I can move on and do the esp mod.

ChargerS.X.T
02-24-2007, 10:18 PM
My RT gets a very rough idle intermittently but very often when warm and the ac is running. I'm talking so rough that my wifes tits are a bouncing up and down.:lol: Took it to small town **** hole dodge thats close to work and of coarse they could not duplicate problem even though it was doing it 2 min after I left the dealer. They told me they scaned it and even checked fuel pressure. Anyone had this problem? I need to fix this so I can move on and do the esp mod.

I rented a 300C and didn't like the rough idling.
The Hemi has tons of torque but the engine isn't refined. It's not an appropriate engine for a luxury car like the 300C better for the Charger and Trucks.

ga charger
02-24-2007, 10:24 PM
I think you have the problem many have had with 3.5 and 5.7 does it feel like you've been hit from the rear.

TripleTransAm
02-24-2007, 10:31 PM
I rented a 300C and didn't like the rough idling.
The Hemi has tons of torque but the engine isn't refined. It's not an appropriate engine for a luxury car like the 300C better for the Charger and Trucks.

My Hemi is smooth as glass at idle. At hot idle, I cannot tell the car is on if I stand in front of it such that I cannot hear the whisper quiet exhaust. If I happen to be distracted after a hot start, I have to stop myself from trying to start it again by making it a habit to check the tachometer. I doubt my Hemi is an exception to the rule, so I'm thinking it's probably not a good idea to judge an engine by a rental car experience. :)

When properly maintained and broken-in (and not beat to heck as most rentals are), I think the Hemi is about as smooth an engine as you can find, at practically all RPMs. Of course, I cannot comment on the 6.1 version but my 20000 mile 5.7 Hemi is aging very nicely.

It's sad when dealer mechanics cannot diagnose such an obvious problem. If there are ignition problems it should be evident in a scantool... do you have any smoke coming out the back when this happens? You mentioned A/C... what RPM is your tachometer showing when this happens? How does the needle behave? Maybe your A/C compressor is bad and seizing up?

ChargerS.X.T
02-24-2007, 10:40 PM
My Hemi is smooth as glass at idle. At hot idle, I cannot tell the car is on if I stand in front of it such that I cannot hear the whisper quiet exhaust. If I happen to be distracted after a hot start, I have to stop myself from trying to start it again by making it a habit to check the tachometer. I doubt my Hemi is an exception to the rule, so I'm thinking it's probably not a good idea to judge an engine by a rental car experience. :)

When properly maintained and broken-in (and not beat to heck as most rentals are), I think the Hemi is about as smooth an engine as you can find, at practically all RPMs. Of course, I cannot comment on the 6.1 version but my 20000 mile 5.7 Hemi is aging very nicely.

It's sad when dealer mechanics cannot diagnose such an obvious problem. If there are ignition problems it should be evident in a scantool... do you have any smoke coming out the back when this happens? You mentioned A/C... what RPM is your tachometer showing when this happens? How does the needle behave? Maybe your A/C compressor is bad and seizing up?

The 300C had only 3000 miles.
Plus, a few professional car reviewers mention that the Hemi is "lumpy" at idle.

daghostmon might have an extremely rough idle but in general the Hemi isn't a very smooth engine. Other brand V8's are better in refinement.

TripleTransAm
02-24-2007, 10:58 PM
Plus, a few professional car reviewers mention that the Hemi is "lumpy" at idle.

I'm speechless.

With my hood up, you can't see my Hemi move at all, it's that glass-smooth.

:silenced:

Crazy_luck
02-24-2007, 11:00 PM
I'm speechless.

With my hood up, you can't see my Hemi move at all, it's that glass-smooth.

:silenced:


Same here. Although, I do have the infamous HEMI tick, which is 100% natural and nothing to be concerned about, mine idles smoother than any of the V8s I've owned (and out of the 25 or so cars I've had, only 1 has been a -banger and I haven't had any 6-shooters)...

ChargerS.X.T
02-24-2007, 11:05 PM
I'm speechless.

With my hood up, you can't see my Hemi move at all, it's that glass-smooth.

:silenced:


Here you go:

The R/T is a smooth and quiet around-town cruiser, its 350-horsepower engine perfectly tuned for this sublime setting, in spite of the 5.7-liter Hemi's lumpy idle.
Source:http://www.motortrend.com/roadtests/coupe/112_0508_muscle_cars_comparison/engine.html

TripleTransAm
02-24-2007, 11:06 PM
I've been searching for any online references to a "lumpy idle" and found only one (Motor Trend *cough*) whereas I get hundreds of hits with regards to "smooth idle".

EDIT: I see you found the same Motor Trend quote. Try doing the same search but with "smooth idle" instead.

It's always a good idea to go out there and try real cars instead of quoting magazine articles. Maybe a road test of a NEW car at a dealership would be the best approach to take.

Crazy_luck
02-24-2007, 11:08 PM
I've been searching for any online references to a "lumpy idle" and found only one (Motor Trend *cough*) whereas I get hundreds of hits with regards to "smooth idle".


Yeah, you can't take anything those "hybrid's rule", Honda biased morons say with anything more than a grain of salt... :smoke:

TripleTransAm
02-24-2007, 11:12 PM
Yeah, you can't take anything those "hybrid's rule", Honda biased morons say with anything more than a grain of salt... :smoke:

Hey, I'm Honda-biased! If it wasn't for the Charger popping into my life, I'd be driving an Accord or a big Acura at this moment.

Magazine test cars are unknown quantities... they can be tweaked from the factory for all we know, or beat to heck by the time they're tested. You never know. Until the day when a car magazine has the budget to go out there and covertly order a brand new car for testing (covertly meaning no "hey, can you give us a magazine-tester discount?"), break it in normally, and then perform real world tests, you have to take their comments with a rather large chunk of salt.

ChargerS.X.T
02-24-2007, 11:15 PM
I've been searching for any online references to a "lumpy idle" and found only one (Motor Trend *cough*) whereas I get hundreds of hits with regards to "smooth idle".

EDIT: I see you found the same Motor Trend quote. Try doing the same search but with "smooth idle" instead.

It's always a good idea to go out there and try real cars instead of quoting magazine articles. Maybe a road test of a NEW car at a dealership would be the best approach to take.


I was just trying to make a point. It was no coincidence that my Hemi rental had a rough idle.

Here is another in case you are doubting me.

Throttle tip-in was as smooth as new vinyl siding (although the idle remains a little lumpy), and the stability control even permitted us to smoke the rear Michelins for three or so feet—just enough to let the neighbors know that, yes, we're driving a practical sedan, but no, it ain't no Camry.

Source:http://www.caranddriver.com/roadtests/9740/dodge-charger-rt-page2.html

I have the 3.5L and while it's not fast it is a smoother engine at idle.
It can be a bit rough when accelerating hard but for my purposes (city driving) it is okay.

TripleTransAm
02-24-2007, 11:41 PM
Two Chargers being tested by a magazine, both black R/Ts w/ R&T, both equipped with NAV, both equipped with dual zone auto climate control, both with U-connect.... and both magazines mentioning a lumpy idle.

Ever consider they might have been the same car?

Could have been something as simple as a preproduction calibration in the PCM at the time of the road tests, or maybe even incorrect oil in the crankcase (adversely affecting the MDs lifters?) which could also account for the rental being rough. (actually, 3000 miles or not, a rental is going to have the bejeezus beaten out of it if it's got a 340-350 hp V8 in it! My 1995 Lincoln Mark VIII rental had much less than that and was already tearing up the track at Ennis TX run after run. Trust me: take it from someone who's rented well over 70 cars in the past 15 years, and been around hundreds of others with my co-workers... you DON'T want to own a former rental car! :) ).

Anyway, I'm sure the 3.5 is a great engine (I was perfectly okay with the idea of getting a 3.5 Charger until stumbling onto this Daytona) but that's not the point here. Just as I cannot comment on the roughness of your 3.5 under acceleration based on one paragraph in a post, it would be equally inaccurate to comment on the Hemi idle based on one rental car (and 2 magazine articles of possibly the same car, with countless others saying the exact opposite).

All I can say is that every Hemi I've been around or sat in (2004 or 2005 300C at work, my Daytona, an early production-date Charger R/T R&T at a dealer) with the engine running has shown NO lumpy idle whatsoever (in fact, an undetectable idle) and my impression from watching a Charger SRT8 move around in my work parking garage is that the 6.1s are probably fairly smooth as well.

the_saint
02-25-2007, 05:45 AM
a week after I bought my 3.5 I took it back to the dealer and told the service tech that the cars idle was rough he told me that this was normal, but after a week of driving I plan on taking it back again because IMO this is not normal.

HemiChemi
02-25-2007, 08:00 AM
I'm speechless.

With my hood up, you can't see my Hemi move at all, it's that glass-smooth.

:silenced:
Mine idles like butta, too.


I'm wondering if he's gotten some bad gas, or perhaps the MDS system is engaging at idle, which it shouldn't.

Smoothing the idle is one of the benefits of the dual-spark plug design!

daghostmon
02-25-2007, 10:15 AM
Please guy's and girls stay on topic with me.

Heres some more info about my problem. Its an 07 RT that I got new in november has 2800 mi and new oil. At times it runs so smooth you don't know its running but other times like a camed up race car. It has done it from day one and I was hoping it would stop after break in. Gas doesn't matter I tried BP, Shell and only once citco ( never again! Chuavas can kiss my white American ass). Car runs at 500 rpm idle with temp gauge in same spot when running rough or smooth. I thought it was getting better but I found out its because I hadn't been using the AC for couple months. Ac load plays a key roll in this. I'm going to take it to the 5 star dealer I bought it from next time I may have better luck there than at the Mayberry like dodge close to work. Just wondering if others had similar problems ?

Crazy_luck
02-25-2007, 10:18 AM
I thought it was getting better but I found out its because I hadn't been using the AC for couple months. Ac load plays a key roll in this. I'm going to take it to the 5 star dealer I bought it from next time I may have better luck there than at the Mayberry like dodge close to work. Just wondering if others had similar problems ?


You might have an A/C compressor problem, possibly a deffective unit, maybe the bearings are a little messed up and causing excessive drag on the drive pully and requiring more effort to run, effecting the idle.

HemiChemi
02-25-2007, 12:53 PM
Please guy's and girls stay on topic with me.

Heres some more info about my problem. Its an 07 RT that I got new in november has 2800 mi and new oil. At times it runs so smooth you don't know its running but other times like a camed up race car. It has done it from day one and I was hoping it would stop after break in. Gas doesn't matter I tried BP, Shell and only once citco ( never again! Chuavas can kiss my white American ass). Car runs at 500 rpm idle with temp gauge in same spot when running rough or smooth. I thought it was getting better but I found out its because I hadn't been using the AC for couple months. Ac load plays a key roll in this. I'm going to take it to the 5 star dealer I bought it from next time I may have better luck there than at the Mayberry like dodge close to work. Just wondering if others had similar problems ?
Pretty sure mine idles at 625 rpm when warm... I'll double-check next time.

500 rpm sounds too low.

TripleTransAm
02-25-2007, 02:39 PM
If you've got EVIC you can put it in diagnostic mode and determine exactly what RPM you're running. Try determining what RPM you are running when everything works well versus when things go haywire. There is a natural load on the engine when the AC kicks in, but the computer is supposed to compensate by upping the engine power slightly to make up for it (older generation motors would actually idle a very small amount higher when this happened).

So either the AC is bad or the throttle motor is not responding properly. Either way, a half-decent dealer should be able to troubleshoot this!

About the Hemi smoothness... went for a drive with the kids around town today, shooting some photos here and there. On the moments where I'd step out of the car to shoot a photo, I swear I couldn't tell the engine was on. No way no how that a rough idle should be considered normal on a Hemi. No way...

RitzRT
02-25-2007, 04:23 PM
Maybe if you bring your wife with you to the dealer they'll be a bit more inclined to try to reproduce the problem? :D

HemiChemi
02-25-2007, 05:11 PM
Pretty sure mine idles at 625 rpm when warm... I'll double-check next time.

500 rpm sounds too low.
Yep. 625 20 or so at idle in park.

daghostmon
02-25-2007, 07:05 PM
Maybe if you bring your wife with you to the dealer they'll be a bit more inclined to try to reproduce the problem? :D

Thats good stuff:) I could say somthing like look you idiots can't you see how rough its idling just look at my wifes tits over there. Hemichemi your right, my idle is around 600 rpm.

King Savage
02-25-2007, 11:47 PM
Thats good stuff:) I could say somthing like look you idiots can't you see how rough its idling just look at my wifes tits over there.

That right there is just plain hilarious.

arfur
02-26-2007, 05:22 AM
Please guy's and girls stay on topic with me.

Heres some more info about my problem. Its an 07 RT that I got new in november has 2800 mi and new oil. At times it runs so smooth you don't know its running but other times like a camed up race car. It has done it from day one and I was hoping it would stop after break in. Gas doesn't matter I tried BP, Shell and only once citco ( never again! Chuavas can kiss my white American ass). Car runs at 500 rpm idle with temp gauge in same spot when running rough or smooth. I thought it was getting better but I found out its because I hadn't been using the AC for couple months. Ac load plays a key roll in this. I'm going to take it to the 5 star dealer I bought it from next time I may have better luck there than at the Mayberry like dodge close to work. Just wondering if others had similar problems ?
Often, with ancillaries like the AC compressor running, the engine ECU is supposed to 'up the idle' slightly to take into account the load increase on the engine. I am wondering if, for some reason, when the compressor is running, the idle isn't being raised..?

HemiChemi
02-26-2007, 06:18 AM
Often, with ancillaries like the AC compressor running, the engine ECU is supposed to 'up the idle' slightly to take into account the load increase on the engine. I am wondering if, for some reason, when the compressor is running, the idle isn't being raised..?
This happened to me once in my Saab. That car used a relay to further open the idle air valve; the relay was bad.


This is from the Service Manual:

ENGINE STALLS OR ROUGH IDLE

1. Idle speed set to low. Correction: (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2. Vacuum leak. Correction: Inspect intake manifold and vacuum hoses, repair or replace as necessary.

3. Incorrect engine timing. Correction: (Refer to 9 - ENGINE/VALVE TIMING - STANDARD PROCEDURE).

My bet's on a vacuum leak! Check your hoses...

TripleTransAm
02-26-2007, 09:00 AM
Forgot to ask... any mods? CAI? Tuning?

daghostmon
02-26-2007, 06:26 PM
No mods done yet. I'm itch en to do the ESP mod but I'm worried it will introduce error codes that might confuse the already confused techs. Do you guys think I should wait ?

TripleTransAm
02-26-2007, 06:47 PM
Personally, I'd wait... it's always best to start with a clean slate, and what you're experiencing is definitely not normal. Find another dealer and get them to do a drive-along with you until it happens. You'd be surprised how many techs out there will completely ignore a crucial detail of how to reproduce a problem... your tech might have even come back after a test drive proudly proclaiming he even "had the A/C off in order to better hear the problem when it occurred, but it never did!".

Of course, there shouldn't be any interaction between the noEsp mod and your problem, but let's not introduce any more variables for dealer techs to work with.

the_saint
02-27-2007, 08:39 AM
Please guy's and girls stay on topic with me.

Heres some more info about my problem. Its an 07 RT that I got new in november has 2800 mi and new oil. At times it runs so smooth you don't know its running but other times like a camed up race car. It has done it from day one and I was hoping it would stop after break in. Gas doesn't matter I tried BP, Shell and only once citco ( never again! Chuavas can kiss my white American ass). Car runs at 500 rpm idle with temp gauge in same spot when running rough or smooth. I thought it was getting better but I found out its because I hadn't been using the AC for couple months. Ac load plays a key roll in this. I'm going to take it to the 5 star dealer I bought it from next time I may have better luck there than at the Mayberry like dodge close to work. Just wondering if others had similar problems ?


This is exactly the same issue I am having. Sometimes the car runs so smooth you can't tell its even on and other time it feels like I am in a drag car (but with less shaking). I am going to the dealer on Thursday to get this looked at.

HemiChemi
02-27-2007, 08:45 AM
Maybe you guys have a cracked insulator on one of your spark plugs...

daghostmon
02-27-2007, 10:17 PM
This is exactly the same issue I am having. Sometimes the car runs so smooth you can't tell its even on and other time it feels like I am in a drag car (but with less shaking). I am going to the dealer on Thursday to get this looked at.

Post back. I'm interested in what they have to say.

Sublimeon22s
02-27-2007, 11:09 PM
I have a 07 R/T with 945 miles on it and I have been experiencing this problem since day 1. Sometimes while sitting at a red light you feel it shake side to side a little, and other times you feel it "jerk" foward like you were tapped by another car from behind (doesnt happen often) ..... I thought this might have been built this way on purpouse to have the cam'ed up "muscle car" feel like how on purpouse they gave the charger no glove box light, hood light, hood struts, door lights, etc to give it a "sports car" vibe (which might i add i thought no hood struts or hood light was stupid for a 07 model car)

the_saint
02-28-2007, 01:29 PM
Post back. I'm interested in what they have to say.

I dropped the car of this mornining to have this issue checked out and my abs recall done. When I get it back I will post the results of their diagnosis. I have a feeling they will tell me they could not dupilcate the issue.

jayman440
02-28-2007, 03:17 PM
I think you have the problem many have had with 3.5 and 5.7 does it feel like you've been hit from the rear.
Ive had that several times...I assumed it was tranny related. mine is 5.7 police.....Is there a fix for it?

ga charger
02-28-2007, 03:32 PM
Ive had that several times...I assumed it was tranny related. mine is 5.7 police.....Is there a fix for it?
not that I've heard. It happened day one on my car , now at 8400miles it happens less. waiting on someone to post the fix

TripleTransAm
02-28-2007, 06:03 PM
Could be tranny-related. Some stalls were attributed to bad valve bodies causing the TCC to lock up at a complete stop, killing the engine. Maybe a fluttering TCC lockup could cause a bad idle? It could definitely cause the little "surge" that is being described at a complete stop.

daghostmon
02-28-2007, 09:14 PM
I have a 07 R/T with 945 miles on it and I have been experiencing this problem since day 1. Sometimes while sitting at a red light you feel it shake side to side a little, and other times you feel it "jerk" foward like you were tapped by another car from behind (doesnt happen often) ..... I thought this might have been built this way on purpouse to have the cam'ed up "muscle car" feel like how on purpouse they gave the charger no glove box light, hood light, hood struts, door lights, etc to give it a "sports car" vibe (which might i add i thought no hood struts or hood light was stupid for a 07 model car)


Mine also has that problem where it feels like someone barely taps you from the rear. But that problem doesn't happen that often anymore so It's not as annoying as my idle problem. But now I wonder if maybe the problems are related.

ChargerS.X.T
02-28-2007, 10:50 PM
Ive had that several times...I assumed it was tranny related. mine is 5.7 police.....Is there a fix for it?


Me too. It has only happened once and I thought the reason was I let go of the brake too much at the red light. But after reading more of this thread I am thinking it wasn't me.

the_saint
03-01-2007, 10:45 AM
The dealer has had my car for 1 and a half days they told me I can pick it up at 5pm. So I'll let you guys know what the outcome is.

TripleTransAm
03-01-2007, 10:52 AM
Me too. It has only happened once and I thought the reason was I let go of the brake too much at the red light. But after reading more of this thread I am thinking it wasn't me.

This could show a possible link to the A/C compressor operation, actually.

Older generation compressors kicked in more violently than modern ones. On an automatic car, if I was holding the pedal too lightly, the surge of the engine reacting (compensating) for the compressor kicking in would sometimes make the car nudge forward a bit. Maybe this might lead to a better diagnosis of the cars that are behaving this way here.

the_saint
03-01-2007, 08:28 PM
Well I got the car back and just like I figured, the dealer said they could not duplicate the my complaints.

HemiChemi
03-01-2007, 09:02 PM
Well I got the car back and just like I figured, the dealer said they could not duplicate the my complaints.
:( *sigh*

daghostmon
03-02-2007, 08:42 AM
I noticed yesterday I was just sitting at the red light idling smooth without AC on and everything good when all of a sudden "BUMP" like being hit from behind again. Then right away she starts idling rough without much load at all this time. I do have to wonder if these 2 problems aren't related now.

TripleTransAm
03-02-2007, 08:59 AM
What happens if you throw it in Neutral when the rough running occurs? Please note your RPM and also see if it changes when you turn off your AC. Does it also do it in reverse once the rough idling begins?

HemiChemi
03-02-2007, 09:03 AM
I noticed yesterday I was just sitting at the red light idling smooth without AC on and everything good when all of a sudden "BUMP" like being hit from behind again. Then right away she starts idling rough without much load at all this time. I do have to wonder if these 2 problems aren't related now.
This sounds to me like the torque converter is trying to lock up when it definitely shouldn't... maybe you have a TCM problem. :(

Did it throw any DTCs?

top banana 37
03-02-2007, 08:20 PM
we both have the same mods on both our daytonas but mine has the rough idle only in the am when it has sit overnight. but both cars have that "bump" you guys keep talking about but it doesnt matter if the accessories are running or not. it does get anoying:)

slvr06CHARGER
03-05-2007, 06:08 PM
I rented a 300C and didn't like the rough idling.
The Hemi has tons of torque but the engine isn't refined. It's not an appropriate engine for a luxury car like the 300C better for the Charger and Trucks.

a 300c aint a luxury car, bmw or a benz are luxury cars:)

slvr06CHARGER
03-05-2007, 06:11 PM
btw i have the bump and the rough idle, when i put it in park or neutral it quiets down

ChargerS.X.T
03-05-2007, 06:20 PM
a 300c aint a luxury car, bmw or a benz are luxury cars:)

I would say it's an American namebrand Luxury Car. The Benz and BMW are German luxury cars while here in the US we have Cadillac, Lincoln and 300C representing Chryslers Flagship sedan.

slvr06CHARGER
03-05-2007, 06:34 PM
I would say it's an American namebrand Luxury Car. The Benz and BMW are German luxury cars while here in the US we have Cadillac, Lincoln and 300C representing Chryslers Flagship sedan.

I agree on the flagship sedan, its just that i never seen it like a luxury car at all, but thats just my opinion.

Sublimeon22s
03-11-2007, 10:38 PM
Im bringing my 07 R/T to the dealer in the morning for this rough idle and infamous "Bump" feeling problem we have been having. Today at a red light I felt the "Bump" like being hit from the rear, when the light changed and I started going, my steering got very tight, gas would not accelerate, and oil light came on as if the car stalled but it actually didnt. When i shut the car off on the side of the road and turned it back on, everything was fine

Ill let you know what they tell me, and if they say they cant "duplicate the problem" their going to need to duplicate how smoothe their face looked because it will be roughed up some

Both a 07 charger R/T with 1194 miles and a 07 chrysler 300 with 1181 miles purchased 2 months ago, and both have seen the dealer atleast 9 or more times each for random problems