Immobilizer Intermittent? Engine Not Cranking Over?

hunds · 2019-01-25T10:51:32+00:00

I have a 2018 Chevy Silverado Z71 4x4. When I turn off the ignition, intermittently I cannot restart the engine for 10 minutes. All lights on the dashboard light up, to include the security light, and work normally even though the engine will not crank. There are no warning lights or alarms before or after I turn off the ignition. After 10 minutes the engine cranks and starts normally. Remote start is inop for the 10 minute interval. Using my spare key and FOB does nothing, for 10 minutes. I have had it to 2 dealers and both say there are no trouble codes, they cannot duplicate the no crank condition, and the system is working fine. Since it usually does it upon returning home I thought it was the vibration from the dirt road I live on. Not the problem. Then I thought my electric gate or garage door opener was the problem (one service tech also thought that was the problem). Not the problem either. It is now intermittently doing it everywhere I go, not just my driveway.

2018 CHEVROLET SILVERADO

12,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC

KASEKENNY

✓ASE Certified Mechanic
18,907 POSTS

Okay. So you have a dead miss on cylinder 8. Have you looked under there to make sure the spark plug boot is fully seated? The most likely cause of this is either the coil was not the issue and it still have another issue or when he reinstalled it, the plug wire/boot did not clip onto the plug and it is misfiring.

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Apr 23, 2021 at 12:05 PM (Merged)

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