1979-1993 & 94 Conv [Subscribe to Daily Digest] |
 | [Main C900 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: knock sensor Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Wed, 15 Oct 2003 14:04:09
In Reply to: knock sensor, MichaelE, Wed, 15 Oct 2003 13:45:50 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Simply put, it detects knock. OK, why?
Knock is detonation, and detonation is bad. You don't mention what year/engine type you have, but in general-
In non-turbo engines, igntion is retarded if knock is detected.
In turbo engines, the knock sensor is critical to the APC (Automatic Performance Control). If the system detects knock, it dials back boost. Knock occurs with advanced timing and high combustion chamber pressure - boost. If the engine is knocking under boost, the piston can be destroyed pretty quickly. The APC dials back boost if it detects knock. This also allows the engine to run on a variety of gasoline grades.
You want to run an engine as close to knock as possible - the most boost, and the most ignition advance. Without a knock sensor, you have to be very conservative in setting boost and ignition advance, so a knock sensor is a performance device. If you do start knocking, performace drops, and in a turbo engine, damage can occur.
Sorry, but I'd recommend replacing the sensor, especially if you have a turbo engine.
posted by 192.249....
, Wed, 15 Oct 2003 14:20:31, Wed, 15 Oct 2003 14:04:09 <-- Viewing This Message
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.
 |
 |
 |
 |
 |
