PT Cruiser Forum  
Advertisements
       

Go Back   PT Cruiser Forum > General Forums > Tech & Performance Forum

PT Cruiser Forum

Advertisements
Rough idle when ac is turned on

 
Like Tree1Likes

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 10 Sep 2016, 09:11 am
Fresh Cruiser
 
Join Date: Nov 2013
Posts: 17
Default Rough idle when ac is turned on

This is a new thread on a question already being covered, but I was told by Mr. PTGT03 that I was using "poor forum etiquette" by not starting a new thread. Other forums are the exact opposite... ok whatever...I just want to find an answer to the problem.

My wife's non-turbo 2007 PT idles very low with the AC on and in gear. It's generating an intermittent cyl-4 misfire code. The plugs are nearly new, I've re-checked the gap and set to .040 as specified. The radiator fan comes on and runs strong with the AC on. It seems like it should automatically idle up when the compressor kicks on, but it's not doing so.

The shop we use for bigger repair work said they have no way to set the idle. Do we need to go to a Chrysler dealer to have them set the idle with AC on?

Thanks for any help offered.
Reply With Quote
  #2 (permalink)  
Old 10 Sep 2016, 10:20 am
VOS's Avatar
VOS VOS is offline
Cool Cruiser
 
Join Date: Mar 2015
Posts: 248
Default Re: Rough idle when ac is turned on

Quote:
Originally Posted by MOTORCITYBADBOY View Post
This is a new thread on a question already being covered, but I was told by Mr. PTGT03 that I was using "poor forum etiquette" by not starting a new thread. Other forums are the exact opposite... ok whatever...I just want to find an answer to the problem.

My wife's non-turbo 2007 PT idles very low with the AC on and in gear. It's generating an intermittent cyl-4 misfire code. The plugs are nearly new, I've re-checked the gap and set to .040 as specified. The radiator fan comes on and runs strong with the AC on. It seems like it should automatically idle up when the compressor kicks on, but it's not doing so.

The shop we use for bigger repair work said they have no way to set the idle. Do we need to go to a Chrysler dealer to have them set the idle with AC on?

Thanks for any help offered.
Oh the horrors....

Have you looked/checked the idle air control valve?


Last edited by VOS; 10 Sep 2016 at 10:33 am.
Reply With Quote
  #3 (permalink)  
Old 10 Sep 2016, 11:22 am
Cool Cruiser
 
Join Date: Jun 2010
Posts: 252
Talking Re: Rough idle when ac is turned on

Rough idle when the AC is turned on is a sign of fan failure. Lots had been posted here on that subject.
Reply With Quote
  #4 (permalink)  
Old 10 Sep 2016, 11:47 am
Obsessed Cruiser
 
Join Date: Aug 2014
Location: Thousand Oaks, CA
Posts: 7,301
Default Re: Rough idle when ac is turned on

This is from the other thread

Quote:
Originally Posted by MOTORCITYBADBOY View Post
Thanks for the reply.
Yes the fan is coming on and seems to be running strong. We get an intermittent code reading cyl 4 misfire. I cant clear it but it seems to clear itself after several cycles. I thinks it's from the idle being so slow with AC on and in gear... like at a red light.
I would suggest checking to see if you have an intake vacuum leak near cylinder #4. It can also be caused by bad spark spark plug or spark plug wire. You need to find out what is causing your cyl 4 misfire that might be affecting your idle.
__________________
If at First You Don't Succeed - Try, Try Again
Reply With Quote
  #5 (permalink)  
Old 10 Sep 2016, 12:06 pm
ptprice's Avatar
Dedicated Cruiser
 
Join Date: Nov 2012
Location: Ormond Beach, Fl. 32174
Posts: 2,113
Default Re: Rough idle when ac is turned on

This might be of help. My son Pricie's 05 PT Vert was having the same symptoms last week end. Just at idle, just with the air on. All the codes were flashin' He has a high-flutin' pro grade reader to diagnose. One was high lighted..battery output. Yup that was it. that old battery had given up the ghost and the low voltage output was the culprit. A new AutoZone battery and all's well. Cherche the battery.

Happy Ptin', ptprice
__________________
SOOO BIG 2005 PT CRUISER, LIMITED EDITION, SIGNATURE SERIES
Custom Cool Vanilla White, 3 Coats. 2.4 DOHC 16V SMPI Eng. Vanity Cover, 4 Spd. Auto Trans. 2.6 Overall Top Gear, Lock-up Torque Converter. Aluminum Chrome Clad 16" X 6" Wheels, P205/55 R16 Cooper Touring tires, Touring Suspension. Chrome Package; Side Spears, Grills, Fuel Filler Door, Door Locks, Handles, PRND3-1 Bezel, Silver/Chrome Shift Ball/Knob, Bright Spoke Leather Tilt Steering Wheel. Chrome Tail Lights, 3/8" Belt Trim. Cruise Control, Power Mirrors, A/C, Deep Tinted Sun Screen Glass, Power Moon Roof, Fog and Back-Up Lights, Rear Spoiler, Variable Front Wipers W/Washers, Rear Wiper/Washer, Key less Entry, Replacement 2001 Dark Taupe Grey Suede/Leather Trim Seats, Dual Under Seat Storage Drawers, Drivers Side Power Seat Height Adjust. Full Length Console, Locking Glove Box, Overhead Temperature/Compass Console, Rear Shelf Panel, AM/FM CD GPS Navigation Radio, 6 Premium Speakers, Back up Camera/ 7" Monitor.
Reply With Quote
  #6 (permalink)  
Old 10 Sep 2016, 12:35 pm
Obsessed Cruiser
 
Join Date: Aug 2014
Location: Thousand Oaks, CA
Posts: 7,301
Default Re: Rough idle when ac is turned on

Quote:
Originally Posted by ptprice View Post
This might be of help. My son Pricie's 05 PT Vert was having the same symptoms last week end. Just at idle, just with the air on. All the codes were flashin' He has a high-flutin' pro grade reader to diagnose. One was high lighted..battery output. Yup that was it. that old battery had given up the ghost and the low voltage output was the culprit. A new AutoZone battery and all's well. Cherche the battery.

Happy Ptin', ptprice
What codes were you getting with the bad idle?
__________________
If at First You Don't Succeed - Try, Try Again
Reply With Quote
  #7 (permalink)  
Old 10 Sep 2016, 01:05 pm
ptprice's Avatar
Dedicated Cruiser
 
Join Date: Nov 2012
Location: Ormond Beach, Fl. 32174
Posts: 2,113
Default Re: Rough idle when ac is turned on

Pricie didn't tell me the codes. Only that it was a shotgun affair with a lot-a-codes and with a recheck at AutoZone and the new battery the problem was solved.

A simple tester on the battery, with AC on, at idle and then with engine not running, will show "quality of voltage." this should superseded the need for any big deal tester. This from two truly "shade tree mechanics!"

Happy Ptin', ptprice
__________________
SOOO BIG 2005 PT CRUISER, LIMITED EDITION, SIGNATURE SERIES
Custom Cool Vanilla White, 3 Coats. 2.4 DOHC 16V SMPI Eng. Vanity Cover, 4 Spd. Auto Trans. 2.6 Overall Top Gear, Lock-up Torque Converter. Aluminum Chrome Clad 16" X 6" Wheels, P205/55 R16 Cooper Touring tires, Touring Suspension. Chrome Package; Side Spears, Grills, Fuel Filler Door, Door Locks, Handles, PRND3-1 Bezel, Silver/Chrome Shift Ball/Knob, Bright Spoke Leather Tilt Steering Wheel. Chrome Tail Lights, 3/8" Belt Trim. Cruise Control, Power Mirrors, A/C, Deep Tinted Sun Screen Glass, Power Moon Roof, Fog and Back-Up Lights, Rear Spoiler, Variable Front Wipers W/Washers, Rear Wiper/Washer, Key less Entry, Replacement 2001 Dark Taupe Grey Suede/Leather Trim Seats, Dual Under Seat Storage Drawers, Drivers Side Power Seat Height Adjust. Full Length Console, Locking Glove Box, Overhead Temperature/Compass Console, Rear Shelf Panel, AM/FM CD GPS Navigation Radio, 6 Premium Speakers, Back up Camera/ 7" Monitor.
Reply With Quote
  #8 (permalink)  
Old 11 Sep 2016, 01:24 pm
Fresh Cruiser
 
Join Date: Nov 2013
Posts: 17
Default Re: Rough idle when ac is turned on

Quote:
Originally Posted by VOS View Post
Oh the horrors....

Have you looked/checked the idle air control valve?

Thanks, I will check and clean the IAC when I get a chance.
Reply With Quote
  #9 (permalink)  
Old 11 Sep 2016, 01:36 pm
Obsessed Cruiser
 
Join Date: Aug 2014
Location: Thousand Oaks, CA
Posts: 7,301
Default Re: Rough idle when ac is turned on

Quote:
Originally Posted by MOTORCITYBADBOY View Post
Thanks, I will check and clean the IAC when I get a chance.
If P0304 code keeps triggering after you reset the DTC's what makes you think that the IAC will fix it? That it might increase the rpm's to compensate for the P0304?

P0304 - Cylinder 4 Misfire Detected

Possible Causes:

Fuel system problems exist
Erratic CMP or CKP Sensor signals
Ignition system problems exist
Engine mechanical problems exist
PCM has failed

Let us know if the information is accurate on still getting P0304. If you are not sure then you might be working on a component that might be working properly.
__________________
If at First You Don't Succeed - Try, Try Again

Last edited by ptcruisersteve; 11 Sep 2016 at 01:48 pm.
Reply With Quote
  #10 (permalink)  
Old 11 Sep 2016, 07:49 pm
Fresh Cruiser
 
Join Date: Nov 2013
Posts: 17
Default Re: Rough idle when ac is turned on

Quote:
Originally Posted by ptcruisersteve View Post
If P0304 code keeps triggering after you reset the DTC's what makes you think that the IAC will fix it? That it might increase the rpm's to compensate for the P0304?

P0304 - Cylinder 4 Misfire Detected

Possible Causes:

Fuel system problems exist
Erratic CMP or CKP Sensor signals
Ignition system problems exist
Engine mechanical problems exist
PCM has failed

Let us know if the information is accurate on still getting P0304. If you are not sure then you might be working on a component that might be working properly.
When I get the DTC, I'm unable to clear it, but it seems to clear after x-number of driving cycles.
The IAC may not be the culprit but it cant hurt to clean it, can it?
A new set of wires wouldn't hurt. It's likely the originals on the car.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Rough idle when ac is turned on roguerafter Tech & Performance Forum 12 10 Sep 2016 08:47 am
'07 PT - Rough Idle, rough acceleration, and shuts off if it idles for too long La_Bruja Tech & Performance Forum 3 09 Aug 2013 07:50 am
Engine doesn't idle up when a/c turned on cmore Canada PT Forum 1 12 Sep 2011 09:12 am
Rough Idle, Rough @60, check engine light NEW Dystroy Tech & Performance Forum 8 12 Jan 2009 09:07 pm


All times are GMT -5. The time now is 11:39 pm.




Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.
vB.Sponsors