I am going to replace the knock sensor on my 98 Legacy Outback w/ 2.5. I got a manual for the car tonight. Its a Haynes manual. The manual says that I need to pull the entire intake manifold to do this. Is this really the case? Also says that I will need to drain the coolant out of the motor. Is this true?

I don't think that's true. On both my '96 and '00 the knock sensor is relatively easily accessible. It's basically below the throttle cables.

[...]It's basically below the throttle cables.

Perhaps this will help: http://www.scoobymods.com/forums/attachment.php?attachmentid=3057

 

The sensor is mounted to the block, and unfortunately the intake manifold doesn't help with the access. You'll probably have to move at least a hose or two and maybe some wiring. It's important that you tighten the mounting bolt to the correct torque; overdo it and you risk cracking the new sensor or at least having it respond incorrectly.

I just did it with some extensions....not too difficult.

You can do it without removing anything with the right combination of extensions. Just keep a bright light and a magnet handy for when you drop the bolt putting the sensor back in.

 

Oh, and a vacuum cleaner. I had to vacuum out all sorts of leaves and debris from underneath the intake manifold. Weird.

 

cheers,

 

Matt

sometimes you need to ignore Haynes!

 

I did remove the clutch cylinder for easier access, but as others have said, just need extensions to reach it, and a magnet to hold the bolt when replacing it does help.

Yes Haynes isn't high on my list for accuracy.

Yes Haynes isn't high on my list for accuracy.

 

well, I DID use only a Haynes manual to rebuild the manual gearbox on my 82 Saab 900. It had all the info I needed for that fairly complex job.

But, the instructions to remove the intake manifold to replace the Subaru knock sensor is simply ridiculous .

Well guys thanks for the info. Got it replaced over the weekend. Still waiting on the cable to come in to replace.