1999 GMC Suburban Repair Question
Asked on December 22, 2010
I have a 1999 GMC Suburban with 136,000 miles. 5.1 liter. The engine pings at idle or when I am accelerating or running on the highway. It seems some what intermittent. It not noticeable when the engine is cold. But when the engine warms up the knock or ping can be heard all the time. what is causing the Ping?
Replied on December 26, 2010
Run a scan and check for a defective knock sensor, the ignition is constantly adjusted by the ECU the knock sensor picks up vibrations in the block from engine pre ignition (pinging) and sends a signal to the ECU for timing adjustment, this sensor may be faulty, start here.
Answered by mhpautos
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