What causes knock? P0327....again?
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,736
Likes: 7
From: Redding CA
What causes knock? P0327....again?
I've replaced both knock sensor's now twice and the wires that connect to the knock sensors all the way to the back of the intake manifold?
My car keeps throwing the P0327 code? Maybe the engine just really is knocking so, what could be causing knock to occur? Too much timing?
Thanks,
DZ
My car keeps throwing the P0327 code? Maybe the engine just really is knocking so, what could be causing knock to occur? Too much timing?
Thanks,
DZ
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
If you can't hear an audible knock it may be false knock--Other things that can create false knock are--noisy valve-train-exhaust leak-exhaust pipes hitting frame- any rubbing together of metal parts from engine torque--I chased a false knock on my 98 for quite some time---finally I de-sensitsed my sensors in the knock tables and it went away--
OH yes too much timing will cause knock as will too lean a mixture which aids in promoting knock--fattening it up some will sometimes help reduce knock
OH yes too much timing will cause knock as will too lean a mixture which aids in promoting knock--fattening it up some will sometimes help reduce knock
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
The best, and only real way to determine if you do have knock is to test the sensors with an oscilloscope. If there is knock, it will show up as a quick AC wave. I would highly recommend doing this before you ever desensitize the sensors.
The best thing to do is to see if you cant pull a little timing and make it go away.
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,736
Likes: 7
From: Redding CA
Yeah, I'm more than happy to just back the timing off if that's what the problem is...I'm more concerned with the check engine light begin off finally then 10 hp. I'll see if the timing adjust will effect the knock...
Thx,
DZ
Thx,
DZ
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Knock, in and of itself, does not set a DTC.
The P0327 posts when the PCM decides it is getting invalid signals from the FRONT knock sensor (the REAR sensor will set a P0332).
Basically the PCM expects to see a fluctuating voltage from the KS when the engine is running. If it gets no voltage, or a steady voltage, then the DTC is set as the PCM knows it should see a fluctuating signal.
Basically remove the fuel rail cover on the left side of the engine, and disconnect the Sensor harness on at the intake manifold.
Using a Digital Multi-Meter set the DMM to the 400k ohm range and measure the resistance from the KS to a ground. You should see (with the engine running), fluctuations between 93k to 107k ohms.
If that checks out OK ... your problem is from the wiring connector on the harness to the PCM. If it doesn't, you have a wiring/connection problem between the intake connector and the KS. Check for bad connectotions at the KR, pinched, exposed (grounded wires) etc.
Post results of first test and I can give you the rest of the diagnostic steps ....
The P0327 posts when the PCM decides it is getting invalid signals from the FRONT knock sensor (the REAR sensor will set a P0332).
Basically the PCM expects to see a fluctuating voltage from the KS when the engine is running. If it gets no voltage, or a steady voltage, then the DTC is set as the PCM knows it should see a fluctuating signal.
Basically remove the fuel rail cover on the left side of the engine, and disconnect the Sensor harness on at the intake manifold.
Using a Digital Multi-Meter set the DMM to the 400k ohm range and measure the resistance from the KS to a ground. You should see (with the engine running), fluctuations between 93k to 107k ohms.
If that checks out OK ... your problem is from the wiring connector on the harness to the PCM. If it doesn't, you have a wiring/connection problem between the intake connector and the KS. Check for bad connectotions at the KR, pinched, exposed (grounded wires) etc.
Post results of first test and I can give you the rest of the diagnostic steps ....
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,736
Likes: 7
From: Redding CA
BlackZ06-I've got to work 8 to 8 today but I'll check the resistance on those wires in the next couple of days and let you know what's up. I've already replaced all the wire up to the back of the intake manifold.
Thx,
DZ
Thx,
DZ
