[General | Members | C900 | 9000 | NG900 & OG93 | 92X | 93 | 95 | NG95 | 97X | 99 | Sonett | Vintage Models | Performance | Detail | Clubs & SOC | Other Cars | Books Movies & Music | Chat | FAQs | Gifts | Photos | Classifieds | Polls | Raffle | Sponsors]

Sonett Bulletin Board
1964-1974
Search:

[Main Sonett Bulletin Board | Post Followup | FAQ ] [ Prev by Date ] [ Next by Date ] Member Login / Signup [Most Recently Edited Saabnet.com Photo Galleries]
Re: Compression testing
Posted by Richie S. (more from Richie S.) on Sun, 20 May 2012 17:08:48
In Reply to: Compression testing, friendofbear , Fri, 18 May 2012 20:57:20
I find a lot of difference in compression gauges, so it matters that you have some experience with YOUR tester. That said I think 140-170 should cover the range of different testers.

Seeing as yours didn't come up much with oil, I expect your ring seal is OK.
I don't understand why you couldn't get the last Cyl. ? the #1, behind the alternator is the hard one. You can get an idea of the one you didn't test by cranking the engine with a spark plug in only a known good cylinder, then again with the plug in only the untested, should sound the same. If it sounds like it is turning over much faster in the untested cyl. It probably has lower compression.

Usually when it has a rough idle but ok at high speeds, it is the valves, as they don't have the time to loose as much at high speed.

Bad ring seal, causes lots of blow-by, oil leaks, etc.
several things con cause rough idle, PCV valve not sealing closed, Idle jet in carb., bad/dirty spark plug, air leak in vac hose/ intake gasket/ decell valve if yours has one.

I would check the valve adjustment, as this is required often, and most people don't do it until a problem arises<g> and these days you have to use an oil additive because they took the zink out of the oil. Without this the valves will close the gap quickly.

Good luck, RGS in Da"Burgh, PA. USA

posted by 151.201.4...
Posts in this Thread:
Members can receive an alert when someone posts in this thread.
Post a Followup

Name:
E-Mail: (Confidential & Secure - Not revealed to other users!)
Send me email when someone posts in this thread: (available to Members)

Subject:

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.
Posting any of this will result in an immediate loss of posting privileges on this site.
Site Members do not see any warning (red) text.

Message:

Optional Link URL: (e.g. http://www.saabnet.com/)
To promote your own Saab site here, you must have a link back to The Saab Network.
Link Title:
Optional Image URL: (e.g. http://www.saabnet.com/img.jpg)


The content on this site may not be republished without permission. Copyright © 1988-2012 - The Saab Network - saabnet.com.
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. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the Saabnet.com Mission and Purpose Page. Please remember that you are not anonymous. Site Donations
Your address is: 23.22.212.158 - Using CCBot/2.0 - Logged.
Site Members do not see red text instructions, green links, and bottom of the page banners.
Click here to see all the Site Membership Benefits!