truck is currently at shop. valve covers taking off and motor looks clean. mechanic says it looks like enough oil is in top and has no sludge build-up and taking off oil pan to ensure there is none in the bottom. Have used mobil 1 full synthetic oil 5w-30 in it since I bought it. Had about 25k on it and now has 120K. Any suggestions of what to look at? Truck had coolant leak which ended up being water pump and a whole in radiator which was just found. DEX-COOL ate the fins up on the water pump. other chevy forums show this as a common issue with 5.3's. Any ideas for a possible solution for this annoying issue? Thanks for any ideas.
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2005 Chevrolet Silverado 1500 Question: Noise during start up especially in cold weather
Answer #1dandd December 30, 2010, 11:50Master
Check the cam lift, possibly the cam lobes are worn, very common for a 327 Chevy V8 or the 5.3. Also check the timing chain as well. If there was a coolant leak, make sure that the dexcool did not mix with the oil also very common on Chevy motors with dexcool.
Replydferris48, January 09, 2011, 17:41Rookie
come to find out its was some sludge in the oil pan, coolant leak was in inner core of the radiator: ate a hole in lower corner. o-ring on oil pump was cracked. switched from mobil one to royal purple and installed new radiator. Now no noise, better gas mileage, better hp, and no coolant loss. Thanks anyways