OVERKILL
$100 Site Donor 2021
Originally Posted By: NHHEMI
Originally Posted By: JetStar
Isn't the knock sensor going to retard the timimng regardless of the cause (piston slap or detonation)? I need to check to see if the knock sensor is active during warm-up or if it only becomes active after op temp is reached, or maybe closed loop?
I had a '96 GMC 1500 that I bought new that had this issue. Seems like it started at around 20K miles. It had 150K on it when I got rid of it. No engine work ever done on it. I always used M1 10W30 synthetic in it. Wish I could say the fuel pump was as reliable.
The piston slap issue has nothing to do with the Knock Sensor. There is too much play, with the engine cold, between the piston and the cylinder sleeve. Once the engine warms up, and things expand, the slop is gone and so is the noise.
But if the slap is hard enough, it COULD trigger the knock sensor. The sensor has no idea what the cause of what it picks up as "knock" is.
Originally Posted By: JetStar
Isn't the knock sensor going to retard the timimng regardless of the cause (piston slap or detonation)? I need to check to see if the knock sensor is active during warm-up or if it only becomes active after op temp is reached, or maybe closed loop?
I had a '96 GMC 1500 that I bought new that had this issue. Seems like it started at around 20K miles. It had 150K on it when I got rid of it. No engine work ever done on it. I always used M1 10W30 synthetic in it. Wish I could say the fuel pump was as reliable.
The piston slap issue has nothing to do with the Knock Sensor. There is too much play, with the engine cold, between the piston and the cylinder sleeve. Once the engine warms up, and things expand, the slop is gone and so is the noise.
But if the slap is hard enough, it COULD trigger the knock sensor. The sensor has no idea what the cause of what it picks up as "knock" is.