Rough idle when cold - Bulletin Board

[General | Members | C900 | 9000 | NG900 & OG93 | 93 | 95 | NG95 | 99 | Sonett | Vintage Models | Performance | Detail | Clubs & SOC | Other Cars | Books Movies & Music | Chat | FAQs | Gifts | Member Photo Galleries | Member Directory | Classifieds | Service/Mechs | Manuals | *Buddy Registry | *Mileage Registry | Polls | What's New | Raffle | Photo of the Month | Sponsors]

93 Bulletin Board
(Search Author's Posts: e.g. Keyword:Author)*Members Only

[Main 93 Bulletin Board | Post Followup | BBFAQ ] [ Prev by Date ] [ Next by Date ] Member Login / Signup [Most Recently Edited Photo Galleries]
Rough idle when cold
Posted by Mark G. in CO [Email] (more from Mark G. in CO) on Tue, 2 Apr 2013 20:15:28
Alert me when someone posts in this thread:

‘08 9-3 2.0T. Last fall engine started running increasingly rough when starting cold, fine otherwise. In Dec., 87k mi, CEL came on – P0304, misfire on cylinder #4. Reset CEL.
• Replaced spark plugs with NGK PFR6T-10G gapped to 0.035 in.
• Replaced ignition coil on cylinder #4.
• Added 20 oz. of Techron II to fuel tank.
Jan, 89k, CEL is on. Code P0304 again. Took car to local indie.
• Checked compression hot: #1-155, #2-155, #3-155 and #4-150. Did cold leakdown test: #1-165, #2-170, #3-170 and #4-80. Indie called other shop who recommended cleaning valves. Added one can of BG-44 cleaner into intake through vacuum line near fuel pressure regulator. Also added can of BG-44 to fuel tank. Recommended continued use of BG-44.
Jan, 90k, CEL came on again and went off 2 days later. Still running rough at cold start; fine otherwise. Added BG-44 to full tank of gas
Apr, 94k. Still running rough at cold start, fine otherwise. Less so in warmer weather. CEL has remained off.
Is this likely the “valve wear” discussed in earlier posts, or something else?

posted by 98.245.15...

Posts in this Thread:
Alert me when someone posts in this thread:

Post a Followup

No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.

Name: Member Login / Signup [Most Recently Edited Photo Galleries]
E-Mail: (Optional)
Re-Enter E-Mail: (Confidential & Secure - Not revealed to other users!)
Note: Please check your spam folder for BB responses.
If you use GMail, follow these instructions from Google so that they appear in your regular inbox.


Posting rules are simple - No for sale/wanted ads or live auctions may be here - use the classifieds.
You may not cross-post your message to multiple BBs.
Personal attacks, insults, or flaming are not allowed.
Site Members do not see any red text, inline ad links, bottom of page anchor ads, box ads, or anti-spam check.

Message: (please no for sale/wanted classifieds - post those in the TSN Classifieds)
To add inline links to your post, use [link][endlink] or use the Optional fields below.
To add inline images to your post, use [img][endimg] or use the Optional Image Link field below.

Optional Link: (e.g.
To promote your own Saab site here, you must have a link back to The Saab Network.
Link Title: (Optional)
Optional Image Link: (e.g.

The content on this site may not be republished without permission. Copyright © 1988-2018 - The Saab Network -
For usage guidelines, see the Mission and Purpose Page.
[Contact | Site Map | on Facebook | on Twitter | Shop Amazon via TSN | Site Donations]

This is a moderated bulletin board - Posting is a privilege, not a right. Unsolicited commercial postings are not allowed (no Spam). Please, no For Sale or Wanted postings, SERIOUSLY. Classifieds are to be listed in The Saab Network Classifieds pages. This is a problem solving forum for over 250,000 Saab owners, so expect to see problems discussed here even though our cars are generally very reliable. This is not an anything goes type of forum. has been a moderated forum since 1988. For usage guidelines, see the Mission and Purpose Page. Please remember that you are not anonymous. Site Contact | Site Donations | Other Sites by SP -
Your address is: - Using CCBot/2.0 ( - Logged.

Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all the Site Membership Benefits!