CEL "Cylinders 1 & 2 Sensor"

[L84THSKY]

I finished the coolant refresh upgrade, fixed one CEL, and now have another. The code says "cylinders 1 & 2 ping sensor". Can anyone tell me where exactly that sensor is? I'm not sure if I actually may have damaged that sensor, or there is a fuel/air leak causing that CEL.

The weird thing is, I feel like I have a DISA valve issue. The car seems to have a hesitation when I hit the 4000 rpm range. Do these DISA valves go bad, can they be tested or lubricated?

Thanks
Eric

[xxxJohnBoyxxx]

Originally Posted by L84THSKY

I finished the coolant refresh upgrade, fixed one CEL, and now have another. The code says "cylinders 1 & 2 ping sensor". Can anyone tell me where exactly that sensor is? I'm not sure if I actually may have damaged that sensor, or there is a fuel/air leak causing that CEL.

The weird thing is, I feel like I have a DISA valve issue. The car seems to have a hesitation when I hit the 4000 rpm range. Do these DISA valves go bad, can they be tested or lubricated?

Thanks
Eric

No you have a bad knock sensor. The 1/2 is located behind the side plastic water pipe on the engine under the intake manifold. The DISA valve feeling is spark advance retard due to the sensor not working and the DME going into minimal spark mode. If you clear the code and immediately take a run you will not get that issue until the sensor code returns. I had the same issue and had to replace the sensors. both need to be replaces since they are pig-tailed together

[L84THSKY]

Thanks for the answer. Being that I just messed around under there doing the coolant upgrade, could I have just not put the sensor wires back on correctly?

Originally Posted by xxxJohnBoyxxx

No you have a bad knock sensor. The 1/2 is located behind the side plastic water pipe on the engine under the intake manifold. The DISA valve feeling is spark advance retard due to the sensor not working and the DME going into minimal spark mode. If you clear the code and immediately take a run you will not get that issue until the sensor code returns. I had the same issue and had to replace the sensors. both need to be replaces since they are pig-tailed together

[xxxJohnBoyxxx]

Originally Posted by L84THSKY

Thanks for the answer. Being that I just messed around under there doing the coolant upgrade, could I have just not put the sensor wires back on correctly?

Possible or you damaged the wire on the front sensor like I did when I changed the coolant pipe on my car. Changed pipe put it back together then had to pull it back apart to do the knock sensor

[L84THSKY]

JohnBoy to the rescue.

The knock sensor lead going to the 1 & 2 cylinder was damaged. It happened just like John said. I took the bolt out of the sensor, tried to pull the sensor out from under the y-pipe coolant piece, and it wouldn't budge. The wire was stuck under the bolt that holds the coolant pipe on the block. Mashed under the bolt is more like it.

Just finished replacing the sensor, made sure it wasn't pinched, and also made sure it wasn't against the engine where it could melt the insulation.

[xxxJohnBoyxxx]

Originally Posted by L84THSKY

JohnBoy to the rescue.

The knock sensor lead going to the 1 & 2 cylinder was damaged. It happened just like John said. I took the bolt out of the sensor, tried to pull the sensor out from under the y-pipe coolant piece, and it wouldn't budge. The wire was stuck under the bolt that hold the coolant pipe on the block. Mashed under the bolt is more like it.

Just finished replacing the sensor, made sure it wasn't pinched, and also made sure it wasn't against the engine where it could melt the insulation.

Before you put it all together make sure you have a clean surface were the knock sensors mount and torque those sensors. I think it is around 30ft# but check that since it's been 2 years since I looked up that torque value

[L84THSKY]

To be honest I didn't torque them down.
No way I was gonna get a toque wrench in there. It's all back together. I cleared the code, and hope it doesn't come back.

Originally Posted by xxxJohnBoyxxx

Before you put it all together make sure you have a clean surface were the knock sensors mount and torque those sensors. I think it is around 30ft# but check that since it's been 2 years since I looked up that torque value

[pnosker]

I have a knock code too-- OBD P0325. I'll scan with Peake and Carsoft tomorrow. It's very persistent and keeps coming back. Car doesn't knock and I didn't do any work lately. Maybe it really is bad.

BTW the Torque value is 15 ft-lbs according to Bentley. Too much and you'll break it, too little and you can get detonation.

Any advice? Pulling the DASC is a PITA!!