Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 06-11-2020, 03:21 AM   #1
Registered User
 
Join Date: Jun 2020
Location: tampa florida
Posts: 7
Garage
rough idle and cel codes

I recently replaced the heater control valve and OAS while i was in there. The car ran fine for about a week. now throwing 300, 302, 304, 306 misfire codes. can anyone give me an idea what to look for. cannot find any vacuum hoses loose.

2003 Boxster S

hstephenson is offline   Reply With Quote
Old 06-11-2020, 04:55 AM   #2
1998 Boxster Silver/Red
 
Join Date: Sep 2017
Location: 92262
Posts: 1,893
Quote:
Originally Posted by hstephenson View Post
I recently replaced the heater control valve and OAS while i was in there. The car ran fine for about a week. now throwing 300, 302, 304, 306 misfire codes. can anyone give me an idea what to look for. cannot find any vacuum hoses loose.

2003 Boxster S
Cherck ALL the AOS connections ensuring they're snug. ALL connections... not just the ones you can see. There's a snap-in tube on the AOS that snakes into the hidden world... and, when you're disconnecting it from the AOS... it could become loosened or dislodged on the other end (hidden world).

My money is on the AOS connections, not that I have any money.
__________________
1998 Porsche Boxster
1986 BMW 325es
2012 Ford Edge Sport

"Ignore the guilt, and take your turn"
Starter986 is offline   Reply With Quote
Old 06-12-2020, 05:58 AM   #3
Registered User
 
Join Date: Jun 2020
Location: tampa florida
Posts: 7
Garage
Thanks for the response
hstephenson is offline   Reply With Quote
Old 06-12-2020, 08:43 AM   #4
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,479
Garage
Quote:
Originally Posted by hstephenson View Post
I recently replaced the heater control valve and OAS while i was in there. The car ran fine for about a week. now throwing 300, 302, 304, 306 misfire codes. can anyone give me an idea what to look for. cannot find any vacuum hoses loose.

2003 Boxster S
Misfire is usually caused by ignition related parts, Ignition coil, spark plug oil fouled from failed AOS ?? I believe the code numbers indicate which cylinder is misfiring so check cyl.# 2, 4,& 6 for oily spark plugs
__________________
Jerk that is constantly criticzing new forum members and overly advertising my rebuilt engine for sale for a highly inflating price along with other miscellaneous parts accumulated over my 20 years of ownership.

Last edited by BYprodriver; 06-12-2020 at 08:47 AM.
BYprodriver is offline   Reply With Quote
Old 06-12-2020, 09:08 AM   #5
Registered User
 
Join Date: Aug 2018
Location: Woodland Wa
Posts: 285
Quote:
Originally Posted by BYprodriver View Post
Misfire is usually caused by ignition related parts, Ignition coil, spark plug oil fouled from failed AOS ?? I believe the code numbers indicate which cylinder is misfiring so check cyl.# 2, 4,& 6 for oily spark plugs
I agree mostly

But misfire on 2,4,&6 are all on the same bank.
So oil intake from the AOS should affect both banks equally.
But the OP just has the misfires on one bank.

I would look for something that would affect that 2,4,6 bank only.
First thing I would do is a very good visual inspection of all the wiring leading to that bank.

Something could have been disturbed by the previous work.
Some connection could be loose.
wiring could have gotten pinched.
Something could be grounding or shorting out.

Something I never see mentioned on this forum is.....
When one has a problem.
Before you even touch anything.
Get a flashlight and do a very intensive visual inspection

Last edited by blue62; 06-12-2020 at 09:15 AM.
blue62 is offline   Reply With Quote
Old 06-12-2020, 09:34 AM   #6
jcp
Registered User
 
jcp's Avatar
 
Join Date: Nov 2019
Location: central okla
Posts: 75
Quote:
Originally Posted by blue62 View Post
I agree mostly

Before you even touch anything.
Get a flashlight and do a very intensive visual inspection
This ^^^^^^^^^^
jcp is online now   Reply With Quote
Old 06-13-2020, 10:27 AM   #7
Registered User
 
Join Date: Feb 2018
Location: Portland OR
Posts: 31
Quote:
Originally Posted by blue62 View Post
I agree mostly

But misfire on 2,4,&6 are all on the same bank.
I believe cylinders 1, 2 and 3 are on the right side (bank 1); 4, 5 and 6 are on the left (bank 2)...
Boxtar is offline   Reply With Quote
Old 06-13-2020, 11:45 AM   #8
Registered User
 
Join Date: Aug 2018
Location: Woodland Wa
Posts: 285
Quote:
Originally Posted by Boxtar View Post
I believe cylinders 1, 2 and 3 are on the right side (bank 1); 4, 5 and 6 are on the left (bank 2)...
Thanks for the correction.
I just assumed that the layout was alternate count from side to side.

Soooo oil from the AOS could be an issue.
But I think I would still start with a good look at the previous work done.

Last edited by blue62; 06-13-2020 at 11:48 AM.
blue62 is offline   Reply With Quote
Old 06-29-2020, 07:25 AM   #9
Registered User
 
Join Date: Jun 2020
Location: tampa florida
Posts: 7
Garage
sorry it took so long to update. you nailed it I had cracked the oil dipstick tube. replace it along with some of the vacuum lines nearby and she runs fine. thanks

hstephenson is offline   Reply With Quote
Reply

Tags
300 , 302 , 304 , 306


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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 05:52 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page