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

 
 
LinkBack Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 07-18-2005, 09:43 AM   #17
Registered User
 
deliriousga's Avatar
 
Join Date: Jun 2005
Location: USA!!
Posts: 1,159
Quote:
Originally Posted by jmabasa
Can the knock sensor get damaged in any way? What happens when the knock sensor is damaged?
Yes it can wear out along with all of the other sensors. The knock sensor feels physical movement in the engine. It has an allowable amount of normal movement that won't affect it since the engine normally vibrates. If a cylinder knocks, the engine jumps and the knock sensor feels it. That's when it starts to compensate and keep the knock from happening.

If the sensor wears out or gets damaged and stops working, it will not adjust for knocking. The engine will be allowed to knock. If the damaged sensor takes in bad readings, it can tell the computer to change the mix and timing to a point where the engine runs rough or not at all.

The problem is almost any sensor can do the same adjustments. The sensors are constantly adjusting, several time per second. Every reading they take is instantly compared to other sensor readings and translated into adjustment. It's pretty amazing to see it work, but it also doesn't take much to mess everything up.

FYI: If you want to avoid future headaches, replace your O2 sensors at 100K miles if they make it that long. That's the expected life of the latest type of O2 sensor.

Here are some good articles on sensor diagnosis http://www.autotap.com/obdii_library.asp
__________________
1987 928S4 Silver Metallic (980)/Navy (TP) 5-Speed
2000 Boxster Speed Yellow/Black 5-Speed
1966 Wife White/Brown Top
1986 Daughter White/Brown Top (Sold!)
1992 Daughter White/Blonde Top
deliriousga is offline   Reply With Quote
 



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 03:08 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page