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bowtie4by 01-05-2018 08:48 PM

Engine noise: What is it?
I have a noise in my engine. The sound resembles a wood drumstick lightly tapping the side of the snare. It disappears when I increase revs to 2000 (from idle approx 500). Is it hydraulic tappet? Is it cam chain? Is it piston skirt slap? I've heard a crank-shaft plain bearing go bad but it is not that deep, solid, or hard of a hit. I don't know about con-rod bearing, but I imagine they are similar. There is no loss in power, nor ease of increasing rpm. Any ideas? Oil is Mobil 1 Delvac (Turbo-Diesel-Truck) 5W-40. Used since breakin was completed. It is mostly PAO. Centistokes at 100/40*C are 97.87/14.5.

bowtie4by 02-27-2018 01:00 PM

Oil and results
I added 1 qt of Mobil 1 High Mileage 10-40 (M1HM1040) and the noise subsided to almost nothing. I am thinking cam-chain. Does anyone know where I can find info on GM V-8 5.3 cam-chain.?

bowtie4by 10-10-2018 06:12 PM

5.3 valve adjustment
I'm fairly certain that the noise is valve clatter.
Is it possible to adjust the 5.3 valve lash?
I can't find anything about it.

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