Knock sensors

gtg737m · Post by **gtg737m** » 31 Mar 2006, 06:19

Hello everyone,
I have a 1994 Volvo 850 Turbo wagon and I changed the knock sensors myself 2 months ago. Yesterday my check engine light came and apparently I have a code for faulty knock sensors. I followed all the steps described in the Haynes book and a Volvo manual that I bought to change the knock sensors but I'm not sure if there is something unique that one has to do whenever the knock sensors are being installed. I have the car at the dealer right now and the mechanic ask me what torque did I applied when I was installing the know sensors since this is very critical in their installation. It sucks that I had to take the car to the dealer now that they charge big time to remove the intake manifold to check the knock sensors. Does anyone know of a way of checking if the knock sensors are good or bad? I'm asking this since I called yesterday the place where I bought the knock sensors and they told me that if the knock sensors were bad, any authorized Volvo dealer would need to replace them. The only thing that suck is that I would have to pay for hand labor since I did this job the first time myself. I appreciate any help that can be offered to figure out a solution for this problem. Thanks.

Post by **MadeInJapan** » 31 Mar 2006, 06:55

Use higher octane gas if you aren't already and I'll bet the code will clear on its own. Just a thought. The correct torque is 20Nm or 14.75 Lb Ft, and front is at 4:00 position and rear is at 5:00 position, if you want to do the job yourself again, but personally, I don't think torque and codes have anything to do with your issue (although position might) and the dealer is just trying to make some $$ from you. What bothers me is that they're bound to find "something else" wrong and charge you anyway.