Rough idle, fluttering speedo after coil problem - DodgeIntrepid.Net Forums - Dodge Intrepid, Concorde, 300m and Eagle Vision chat
Reply
 
LinkBack Thread Tools Rate Thread Display Modes
post #1 of 114 (permalink) Old 01-05-2017, 10:58 PM Thread Starter
Intrepid Newbie
 
Join Date: Jan 2017
Posts: 58
Feedback: 0 / 0%
 
Rough idle, fluttering speedo after coil problem

Drove my car after a very cold night, engine light on and car idling rough, speedo fluttering when speeds between 45-50. Code indicated a problem with cylinder 4. Opened hood to find a mouse nest sitting on the plenum and wire to coil of cylinder 4 disconnected. Fixed wire, replaced burned out coil and all plugs. Restart car with no new codes, but idling rough and "hiccuping" again at same speeds with subtle speedo fluttering at same time. And still no CEL! Does have a shot front muffler. Sensors? Related to the exhaust? Other coils? Where do I start?
lakeviewcolleen is offline  
Sponsored Links
Advertisement
 
post #2 of 114 (permalink) Old 01-05-2017, 11:31 PM
Woober Goobers!

 
Ronbo's Avatar
 
Join Date: Mar 2005
Location: Tiny Pebble, AR
Posts: 42,000
Feedback: 44 / 100%
                     
What year and model? Which engine?
Ronbo is offline  
post #3 of 114 (permalink) Old 01-05-2017, 11:36 PM Thread Starter
Intrepid Newbie
 
Join Date: Jan 2017
Posts: 58
Feedback: 0 / 0%
 
2002 Intrepid, 3.5 L
lakeviewcolleen is offline  
 
post #4 of 114 (permalink) Old 01-05-2017, 11:56 PM
Woober Goobers!

 
Ronbo's Avatar
 
Join Date: Mar 2005
Location: Tiny Pebble, AR
Posts: 42,000
Feedback: 44 / 100%
                     
What Brand/Type spark plugs did you use?
Ronbo is offline  
post #5 of 114 (permalink) Old 01-06-2017, 07:52 AM Thread Starter
Intrepid Newbie
 
Join Date: Jan 2017
Posts: 58
Feedback: 0 / 0%
 
Champion 7034 came out and Champion 3034 went in. Why do you ask? Please bear in mind that I'm a 40 something single mother and veterinarian. I have a sharp mind but no official mechanic training. Earlier this year my car was having issues and after replacing an 02 sensor, speed controls, and the PCM/TCM, I figured out is was the solenoid pack. So I dropped the tranny pan and valve body and replaced the shift solenoid. I've had no problems since and no CEL. I did note however when I changed the speed sensors that there was some fine metal particles in the tranny fluid. I expected that soon the tranny would go but until the mouse nest the car has been great with no problems and no CEL.
lakeviewcolleen is offline  
post #6 of 114 (permalink) Old 01-06-2017, 07:05 PM
Woober Goobers!

 
Ronbo's Avatar
 
Join Date: Mar 2005
Location: Tiny Pebble, AR
Posts: 42,000
Feedback: 44 / 100%
                     
I ask because some brands of spark plugs don't play well with the engines in our LH cars. They cause misfires, etc.

If you changed the spark plugs out with the same brand/type that were in there originally then that's a good start. Did you change them or someone else? What was the gap set at?

You said originally the wire to the coil was disconnected? Was that the case or was it damaged?

You say the coil was burned out? How was that determined? Where did you get the replacement coil?

Just trying to get the details and help you out. Lots of variables here. Does the CEL (Check Engine light) ever flash on acceleration? That would be an indication of multiple misfires of the spark plugs.

"Just Junk It LLC."
"Just Charge It"...shit I fried my ECM!
Member of the Sold SRT-8 Magnums of DI.net Club!
Perky Jerky for Everyone!!
Crazy Rons House of Mega Deals
Ronbo is offline  
post #7 of 114 (permalink) Old 01-06-2017, 07:33 PM Thread Starter
Intrepid Newbie
 
Join Date: Jan 2017
Posts: 58
Feedback: 0 / 0%
 
I changed the plugs but didn't check the gap. CEL indicated misfire at cylinder 4, so pulled the coil and it was melted and obviously bad. Bought new coil at parts store. The wire was disconnected but had melted coil stuff on it but didn't burn into the plastic insulation. After reconnecting the wire, replacing the coil and all spark plugs, the CEL has not come back on. But it still is rough with the fluttering speedo. Can it be exhaust related.
lakeviewcolleen is offline  
post #8 of 114 (permalink) Old 01-06-2017, 07:34 PM Thread Starter
Intrepid Newbie
 
Join Date: Jan 2017
Posts: 58
Feedback: 0 / 0%
 
Check engine light doesn't come on anymore.
lakeviewcolleen is offline  
post #9 of 114 (permalink) Old 01-06-2017, 08:03 PM
Woober Goobers!

 
Ronbo's Avatar
 
Join Date: Mar 2005
Location: Tiny Pebble, AR
Posts: 42,000
Feedback: 44 / 100%
                     
Wasn't talking about a steady on CEL. That notifies you of codes. The Flashing CEL during acceleration is a Multiple Misfire indication.

You really need to verify/check the gap on the spark plugs when installing new ones.

SPARK PLUGS
Engine Spark Plug Gap Thread Size
2.7L RE10PMC5 0.048 TO 0.058 in. 14mm (1 in.) reach
3.5L ZFR5LP-13G 0.048 TO 0.053 in. 14 mm (3/4 in.) reach
Ronbo is offline  
post #10 of 114 (permalink) Old 01-06-2017, 10:39 PM Thread Starter
Intrepid Newbie
 
Join Date: Jan 2017
Posts: 58
Feedback: 0 / 0%
 
When this first happened yes there was the flashing CEL, but since reconnecting the wire, replacing the coil, and changing the spark plugs there has been no steady on or flashing CEL. So check the plug gaps as a first something to try? Thanks!!
lakeviewcolleen is offline  
post #11 of 114 (permalink) Old 01-07-2017, 03:57 AM
Intrepid Pro
 
98IntrepidTan's Avatar
 
Join Date: Dec 2008
Location: Georgia, USA
Posts: 3,218
Feedback: 0 / 0%
                     
After checking the spark plug gaps, consider removing and cleaning the transmission speed sensors. Since you had metal in the transmission before, they could be covered with fine metal particles which could be affecting their function. Does the speedometer fluttering issue seem to be getting worse?
98IntrepidTan is offline  
post #12 of 114 (permalink) Old 01-07-2017, 08:01 AM Thread Starter
Intrepid Newbie
 
Join Date: Jan 2017
Posts: 58
Feedback: 0 / 0%
 
If the speed sensor is "dirty" why would the symptoms only start with the coil issues? No, the speedo issue is not worsening, only happens at speeds of 40-55 when the rough engine is pronounced. As I am accelerating in this speed range it is as if the engine is bogging out, as if it may stall, is very rough but if I accelerate through it to about 65 mph it is better.
The plugs previously in the car were double platinum and the ones installed now only had platinum on one side, Champion 7034 replaced with Champion 3034. Does this matter? I will check spark plug gaps first. Then if needed I'll clean the speed sensors and obviously change fluid and filter.
Thanks for the help. Beginning to get to know every part of my car, inside and out.
lakeviewcolleen is offline  
post #13 of 114 (permalink) Old 01-07-2017, 08:07 AM Thread Starter
Intrepid Newbie
 
Join Date: Jan 2017
Posts: 58
Feedback: 0 / 0%
 
Just to clarify, the speedo flutter is very subtle, doesn't jump around drastically, maybe flutters between a 2-3 mph range. But with it is the rough driving, and is obviously burning thru gas. And only flutters in the speed range when the rough engine is the worse at 40-55 MPH. And no CEL light thru any of this since coil issue fixed.
lakeviewcolleen is offline  
post #14 of 114 (permalink) Old 01-07-2017, 02:22 PM
Intrepid Pro
 
Join Date: Feb 2002
Location: Virginia, U.S.
Posts: 14,527
Feedback: 4 / 83%
                     
No promise of a magic bullet, but some things to consider:

You said you replaced the PCM. Which came first: Bad PCM or bad coil? I ask because there have been several instances on this site over the years of the PCM failing such that the outputs that drive the ignition coils stick on with either a high duty cycle ('on' time vs. 'off' time) or solid 'on'. There is high current flow and heat generated during coil 'on' time. The coils are designed only for normal ignition signals, which are very low duty cycle. Likely your PCM output for that coil failed giving a high duty cycle or solid 'on' for that coil, which is why it melted and failed. Usually that PCM failure affects more than one coil output. I wonder if you have one or more walking-wounded coils that need to be replaced - bad enough to cause rough running under certain conditions, but not bad enough to throw a code.

As far as a connection between the rough running and speedometer jitters, I can only wildly speculate. For example, if you have a "wounded" coil, it may be partially shorted - i.e., still marginally operating but pulling lots of current from the PCM under certain engine speeds/operating conditions. That could be affecting operation of other circuits, like the tranny speed sensor circuits (which are also in the PCM) at the same time as the rough running.

Other things that come to mind:
• Spark plugs: Your single plat plugs are fine. Double plat is only needed for ignitions that operate plugs with reverse polarity - not the case with these cars. The NGK/NTK ZFR5LP-13G (AKA 7781) that Ron mentioned is the plug number stated in the '02 FSM. The prior year FSMs called out Champion RC12PEC5 (AKA 3034). RC12PEPB5 (AKA 7034) is the double-plat version of the same plug. My guess is that a previous owner or mechanic replaced the factory NGKs with those. Either should do fine. Is it possible that Chrysler switched to the NGKs due to issues with the Champions? Might not be a bad idea to replace them with the NGKs, but I would be surprised if that is causing a problem.
• Spark plugs need to be torqued to the proper value (20 ft-lbs) to ensure that they make good electrical ground contact with the head - poor electrical contact can lead to rough running.
• There is a spiral-wound spring-like electrode coming off of the output of the coil that makes the electrical connection to the top of the spark plug. More than a few people have had corrosion develop between that electrode and the output of the coil causing poor electrical conductivity and poor running. You can pull the electrode out of the coil and clean the recess in the coil and the electrode of corrosion - put a light coating of silicone grease (AKA dielectric grease) on the coil output and the electrode before re-assembling. New coils come with the electrode, so that would eliminate that issue on coils that are replaced.
• Make sure the two screws that attach each coil are tight (60 in-lbs). Probably not a big deal, but may be important for cooling of the coils (by heat sinking to the valve covers or heads).
• There is a black part (box shaped, 1/2 to 1" on each side) that is attached by a small stud to each valve cover or head - there will be a single black wire from the engine harness to the black part. It is a capacitor that filters ignition noise from the electrical power. For the capacitor to do its job, the wire has to be intact and connected, and the capacitor has to be firmly attached to its bracket (which is screwed to the valve cover or head).
• Poor power (+12 volt) and ground connections between the battery, engine, and computers can cause all sorts of quirky little problems like this.
I don't want to get your hopes up, and I realize that you will have to spend money with your fingers crossed to check some of those things. Sorry, again, that I don't have suggestions for diagnosing without buying new parts.

As always, comments from others are welcomed.


'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs

Last edited by peva; 01-07-2017 at 02:35 PM.
peva is offline  
post #15 of 114 (permalink) Old 01-07-2017, 03:19 PM
Woober Goobers!

 
Ronbo's Avatar
 
Join Date: Mar 2005
Location: Tiny Pebble, AR
Posts: 42,000
Feedback: 44 / 100%
                     
I'm guessing the PCM was replaced before the coil issue for the transmission problem? If that's the case then it's possible now that the damaged coil took out the driver in the new PCM.

Seeing as how you have an SE Intrepid it shouldn't have SKIM. Is the head of your ignition key black or gray plastic? If black then no SKIM so no programming headaches for a new PCM. The good news with that is you should be able to get a used PCM cheap and it wouldn't require any programming for security features.

"Just Junk It LLC."
"Just Charge It"...shit I fried my ECM!
Member of the Sold SRT-8 Magnums of DI.net Club!
Perky Jerky for Everyone!!
Crazy Rons House of Mega Deals
Ronbo is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the DodgeIntrepid.Net Forums - Dodge Intrepid, Concorde, 300m and Eagle Vision chat forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Member names may only be composed of alpha-numeric characters. (A-Z and 0-9)

!!ATTENTION ADVERTISERS!! If you intend on advertising anything on this forum, whatsoever, you are required to first contact us here . Additionaly, we do NOT allow BUSINESS NAMES unless you are an Authorized Vendor. If you own a business, and want to do sales on this site via posting or private message, you will need to follow the rules. Shops, Stores, Distributors, Group Buys without being authorized will see your account terminated.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Random Question

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome