2001 Chevrolet Blazer Q&A
2001 Chevrolet Blazer Question: Why is my new engine in my Blazer making sounds like popcorn popping when warm?
Brand new engine, got it back Saturday. After engine is warm I hear popping sounds that sound like popcorn popping. Only happens after engine is warm. Also, can't hear it when hood is up, only when sitting inside. Doesn't matter if I am in park, drive, or reverse. Garage not being very helpful. - djgarrett
Are you sure it's the engine? If you can only hear it from inside the truck, and not outside with hood up, in a garage. If it was your engine, you would hear it outside even better. Might start looking inside. - ProfessorG
Sounds like popcorn popping , hum,,,. Have the distributor, the dist cap and rotor checked to see, after it's warm and loosened up, if there is any interference. Will be more pronounced from inside the cab as well. However this usually sounds like it's coming from the heater area. Can usually feel it on the dist cap or listen to it with an auto. stethoscope. That's the only thing i know of that can cause that rapid, repetitive type sound in the rear of the engine other than maybe the flexplate/flywheel. - pushrod