hi my 2004 tahoe 5.3 making bad knocking noise bottom end above oil pan with 165000 miles tried lucas oil stabilizer with 20w50 casrol gtx noise is gone but started making noise at cold start for few second like piston slap noise but goes away with a minute does anyone in here have same problem as i have ?
5.3 2004 tahoe engine
- Thread starter ali saleh
- Start date
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I have an 01 Tahoe that makes a little knocking noise at start up. From what I researched it is piston slap. Have 114k on it. This is my 3rd chevy truck with the 5.3 and they all had the same noise. All were bought used so i couldnt say when it first started. Does not burn or leak any oil between synthetic oil changes. If it started to knock after it was warmed up I would be concerned. Only lasts for 30 seconds on a cold start runs smooth and quiet after that. I remote start it from inside so I don't have to listen to it.
SnowDrifter
Full Access Member
Holy shit 20w50 with lucas????
What's your oil pressure like with 5w30?
What's your oil pressure like with 5w30?
LOL ... to expand.
The clearances on these motors are "apparently" really tight! Hence the 5-30 oils! Don't know where I read it but an article a long time on oil viscosity. If the tolerances are really tight a heavy oil can't flow between the crank bearings and the crank, heat builds up on the edge of the bearings as the oil "tries" to force it's way thru.
Long story short the 50 weight is going to do more damage not less! Odd thing my now old school Porsche 1989 951 S, can apparently run anything between a 10-30 and 20-50 with no issues?? And my freinds M3 BMW V8 400 hp, 32 valve Double OHC runs a 60 weight oil??? Freaking German cars go figure.
At anyrate most likely best to get the 50 weight stuff out of there!
FrankU
Full Access Member
LOL ... to expand.
Long story short the 50 weight is going to do more damage not less!
At any rate most likely best to get the 50 weight stuff out of there!
I'll back Chip18's advise ! Start by checking your oil pressure with a known good gauge.
