engine knocking and pinging
Asked by GuruDTXFXM Jun 24, 2024 at 01:47 AM about the 2004 Cadillac DeVille Sedan FWD
Question type: Maintenance & Repair
I have a 2004 deville that is knocking and pinging and stalling. I installed new
plugs and new coils on each plug. It did not improve at all. I connected my
scanner and set it to live mode. The timing is all over the place. From 2 to 20. It
just jumps up and down rapidly. Any idea what is causing this? Please help
me.
3 Answers
This vehicle requires premium grade gasoline. This is not a suggestion from Cadillac, it's a requirement. The timing is all over the place because the knock sensor is hearing the knocking, sending a signal to the computer, and the computer is adjusting the ignition timing to try to get the knocking to stop. So, try using the correct grade of gasoline and see if the knocking and pinging stops. If it doesn't, I'd suspect an internal engine problem. Such a a bad bearing, or possibly a stuck lifter. A timing chain problem will cause the valve timing to be retarded (late) but that should set a trouble code. Jim
James is right, when Cadillac says premium fuel they mean premium fuel. I had a Deville and tried running regular in it, it was a very bad idea, I had to put in three bottles of octane booster just make it drivable. So this sounds like low octane rating fuel problem. The only other option would be a bad carbon deposits inside the combustion chambers.
Make sure you didn't put E85 or diesel in it.
