Knock sensor replacement question

[Nick Lamendola]

Hi,

I need to replace the knock sensor on my '99 Outback. I've located the
sensor. Can I gain access to the connector by just removing the alternator?
Do I have to drain the radiator fluid? The Haynes manual I have says to
remove the intake manifold to remove it. That looks like overkill just to
replace a sensor. Anyone have any tips on how to go about replacing the
knock?

Thanks for any and all advice.

Nick L

 

[Creative]

I had mine done by the dealer, including diagnosis, the bill was less than
$200 and they only had the car until lunchtime.

Images to Laugh, Smile & Cry over !
Ian Wharton Creative Photographics
Brisbane Australia

 

[Nick Lamendola]

Yes, I could do that, but then I would lose the pleasure of struggling to
replace it my self. I was just looking to see if someone could verify if my
Haynes manual was correct. I don't think the intake maifold could be removed
that quickly.

 

[Bob Bailin]

I'm not sure how it is on the Outback, but the knock sensor
is usually held in place by a single bolt, usually with a 10mm
or 13mm head. If you can get to the bolt with a ratchet and
extension and/or u-joint, you can remove & replace the sensor.
Use a 6-point socket just to be safe. If you can get to it by
simply removing the alternator, then that's the correct way.

Bob

 

[ed]

Replaced one on an earlier car, didn't need to remove manifold in that case.
ed

 

[Dtitan]

it's not under the alternator. That's the oil pressure sender.
The knock sensor is behind the intake at the rear of the block (on top) on
the drivers side.
it looks like a black cylinder with a plug coming out the side. It has ONE
bolt going directly throught the top.

I have THE Subaru service manual for this. I can't post up a page to show
you if you want.

-Dominic Acia

 

[Nick Lamendola]

Thanks, but I know where it was located. Thought I had to remove the
alternator to get at it. I did not after all. It took about 40 minutes to
replace. The hard part was cutting the cable tie that held the pig tail and
a couple of other lines togeteher. I used a magnetic tip probe to get the
bolt up after loosening it. The next difficult part was getting the bolt
back in the place on the new one. The Haynes manual I have must be too old.
They wantn't me to remove the intake manifold and drain the coolent. I
erased the code and eveything is OK. Thanks for all the replys
-Nick L

 

[Guest]

I have replaced mine two weeks ago on my Outback '97. It wasn't easy, but
not so hard either. After changing spark plugs it's nothing...

First, I have removed black "air intake box". Loose metal rings on the
manfold and on the filter box. Unscrew bolts on the holders and remove whole
"air box".

Second, you should squeeze the metal ring and remove rubber hose next to the
knock sensor. You will have small amount of cooling liquid.

Third, use wrench head with extender. Get them on the bolt, and then put
wrench arm.You will have 60-90 degrees of free movement, but ti's sufficient
to unscrew the bolt. It's easied to do when you lay down on the engine (I
tried to do it from left and right - almost impossible).

Then bolt new sensor in, and assemble everything back. Everything took for
me about 15 minutes.

Good luck.