LBZ / Allison - Cracking, snapping, popping, ticking sound???

[More Power]

GM decreased the engine oil pressure in the LLY and LBZ engines below that produced by the LB7. The odd snapping (produced by the earlier LB7) didn't seem to be an issue with the newer engines - at least people stopped talking about it.

To me, the snapping sound produced by the LB7 was more like a loose flat washer intermittently rattling/ticking inside the driver's side aluminum intercooler tube. I felt then (and still do) that the sound was due to new oil gassing-off and creating gas bubbles that were compressed/popped in the engine's main/rod bearings. I always heard the sound right after an oil change and for about the next couple hundred miles - then not again till the oil was changed.

Jim

[gophergunner]

i always thought it was metal parts expanding as it warmed up........

similar to the sound you hear from ducts in the house when the furnace kicks on maybe......

just my thought but i'm not sure

[DieselMonk]

Not sure what you are talking about the snap, pop, cracling sound, but I sure do know what you are talking about that ticking sound. There is a bulleting out for it, but GM says do not fix and it is normal. Mine is ticking too, sounds like some one using a mechanical type writer with one finger. Sounds worse on the drivers side wheel housing, when it's warm outside and the truck hasn't reached op temperature. However, it shouldn't effect anything, besides making noise.

[EdHale]

As I said earlier, mine does this too, but only while it is coming up to operating temp. Then it is quiet. Did anyone actually say what it is? If so, I guess I missed it. Ed