2000 Silverado 5.3 - Start Up Chatter

[GMC-AT]

Guys, 

I have 2000 Silverado - 5.3 with 250K miles. Truck runs great, it just has the typically value chatter at start up - which lasts for maybe 60-90 seconds

My question.. is there anything I can add to the oil that would help?  I run 5w30 and change regularly.  I was thinking about adding some Lucas oil stabilizer. Or just running thicker oil?

Part of me thinks the thicker oil will actually make the start up chatter worse since it will take the thicker oil longer to reach the top end of the motor. 

Any idea that don't involve tearing into the engine would be great.. thx

[diyer2]

I would try 10 W 40.

I have gone to thicker oil with high mileage motors before with no issues.

Had a Class A motor home with the motor(454) stuffed in one of those covers between the front seats like a van.

Living in Colorado with the mountains and pulling a boat I used 20 W 50 racing oil in it with a 2 quart oil filter to get an extra quart of oil init.

Never had a problem. Let it warm up before moving it.

It was a low mileage motor, 20 + K miles.

Brother in law has a 1988 Chevy 2500.

When he tows for a long distance he puts 30 weight in it. 

Has 40 K miles of towing on a 180 K mile motor.

 

 

[GMC-AT]

ok.. I'll try 10W40.  I guess one theory is it's takes the thicker oil longer to reach the top end at cold start thus creating  more value chatter.  But another theory is that ticker oil may leave a "thicker coat" of oil on the top end when the truck sits cold... thus reducing chatter at cold start. 

Don't know.. I'll experiment and see..

[sefiroxx]

Oil thickness change over the years was tied to the quality of manufacturing. As the mfg got better, the spaces between metal got tighter requiring thunder oil.

Modern engines with a lot of miles will have worn the metal just enough to require a thicker oil to properly lubricate.

Time to the top of engine change is a miniscule difference. It's more important that the oil channels are all open, pump is working so that oil is dispersed everywhere on surfaces where it will remain when the engine is shut off

[Black02Silverado]

No oil thickness will make a difference.  It is the nature of the beast for our 5.3's.  Mine does it as well and has been since new.  I only have 186k on mine but there are some out there with 350k and no issues.  I wouldn't worry about it.

[NothingbutGM]

Also at 186k in my 5.3.  The valves do make some noice shortly after start up but it only happens when super cold. I wouldn’t worry about it much 

[Black02Silverado]

Also note that oil thickness doesn't make a difference.  I'm running 0w-20 in mine now and it still does it.