5.3 has more cold start knock with NAPA Silver

[strat81]

Originally Posted By: SteveSRT8
Several had carbon knock, that's a very similar sound that many cannot diagnose, super easy to fix.


Indeed, or possibly a combination of typical piston slap with carbon knock.

My 5.3 sees a lot of short trips, idling, and trips in town with speeds generally under 35 mph. When my wife drives it with the kids in the back, it barely goes over 2,000 RPM.

On the odd week that I drive it, I get a bit more aggressive with it and find the engine is quieter at idle and at start up.

It seems my 5.3 really likes to be worked. However, there's not much I can do to help a 5,000 pound SUV stretch its legs when it lives in a suburban environment.

 

[Islandvic]

To answer some questions and respond to some comments, the cold start knock i speak of is also known as "csk" or "piston slap" which is very common on GM 5.3's and 6.0' from '99-'06.

It has never neen to much of an issue. Every year or when the OLM comes on (which ever comes 1st) the oil has been changed with whatever synthetic is on sale and usually an oversized AC Delco filter. I think the FF and first OCI was the only time it ever had conventional oil in it.

 

[Merkava_4]

Originally Posted By: tswm
Originally Posted By: Merkava_4
getcha some 10W-40. You don't need 5W-30 in south Texas.


10W40 is worse than 5W30. If we are talking about 10W40 conventionals, we are still talking about 3K mile OCIs; 10W40 is effective for a little bit, then varnishing and sludging process begins, not as bad as in the 70s, but that's the consequence of requiring too much VIIs for that grade. Now G-Oil 5W30, that is an exception, because that is ester synthetic.

OP's climate calls for either Max Life 10W30 (the older formulation) or Pennzoil HM 10W30. If as I'm guessing OP's engine is OHV, if so, then another good choice is a PYB blend, mostly PYB 10W30 plus a quart or two of PYB SAE 30.


Just to clarify, I recommended 10W-40 for the piston slap.

You're saying that 10W-40 is effective in treating the piston slap temporarily, but then starts varnishing and sludging and then becomes ineffective in treating the piston slap - correct?

 

[KCJeep]

Originally Posted By: Islandvic
To answer some questions and respond to some comments, the cold start knock i speak of is also known as "csk" or "piston slap" which is very common on GM 5.3's and 6.0' from '99-'06.

It has never neen to much of an issue. Every year or when the OLM comes on (which ever comes 1st) the oil has been changed with whatever synthetic is on sale and usually an oversized AC Delco filter. I think the FF and first OCI was the only time it ever had conventional oil in it.


Okay I misunderstood your issue, I've not found any oil or filter that makes much difference with piston slap. We've had a couple other notorious GM slappers as well, a 3.1 and 3.4 v6. We still have the 3.1 in the Lumina. It slaps so loud at cold start I can easily hear it in the house when my daughter starts it and pulls it out of the driveway. Yet it plugs on seemingly unaffected.

 

[tswm]

Originally Posted By: Merkava_4

Just to clarify, I recommended 10W-40 for the piston slap.

You're saying that 10W-40 is effective in treating the piston slap temporarily, but then starts varnishing and sludging and then becomes ineffective in treating the piston slap - correct?


Correct basically, although I was not thinking of piston slap. IMO if SN 10W40 conventional route be taken, around 6 month OCI max and probably less than 3.5K miles, although it really depends on how it will be operated; here I am assuming that OP's is a work truck (probably OHV engine), idling frequently, mix of short and highway trips. I meant that if 10W40 conventional is used regularly again and again, then unless such short OCIs be observed, gradual varnishing and sludging is inevitable. It would be much more difficult to get such negative result, if utilizing conventional 10W30 and/or 30, even if OP proceeds to neglect oil changes. With SN 5W30 and 10W40 conventionals, one must be alert because of additional VIIs (though overall SN specs make for better motor oils than ever before), but more especially with the 10W40 grade.

 

[Tzu]

I have the same truck and engine and the best thing I did was switch back from synthetic to conventional. After running synthetic for over 100,000 miles, I figured it was long enough time to see whether it did anything or not. To me, all it did was cost more money. I went with Wix filters instead of AC Delco and it has seemed to help noticeably more. Also, the guys up north like us seem to hear it more than down in Texas or Florida. Come to think of it, in summertime here I almost never hear my truck slap. I think if you could "get on it" now and then that would help as well. I live near a huge wildlife refugee so there are a lot of back roads. The slap reminds me it never left in October...
Originally Posted By: dave123
Originally Posted By: Turk
Could be "Piston Slap". I had it REALLY BAD in my 2000 5.3L Sierra.



I bet it is and same here sounded like it was going to come apart every morning at start up. No filter or oil made it better it just didn't matter.

 

[Islandvic]

let me respond to some of the posts

901memphis, yes i am prob more sensitive to the sound!

turtlevette, the orientation of my filter is vertical, not horizontal. Are you using the M1 AFE 0w-30? I stopped using M1 in my 5.3 b/c it seemed to make it louder also. What year is your truck?

Merkava_4 & TSWM, thanks for the input on choices for grades of oil, but i have a multi-OCI stash of 5w-30 and 10w-30 synthtics from G-Oil, NAPA, Castrol Edge Ti and Maxlife Syn Blend (all between $1-$3qt on sale).

Tzu, in my case, Synthetic is cheaper than conventional.

Its time for me to get a new oil drain catch pan. I may drain the oil into a new catch pan, remove and replace the NAPA Silver with a Bosch Premium filter. About 3 months ago I bought 4 to try out b/c I found them for $3.50 each.

I'll report back if the switch to the Bocsh Premium filter changes anything.

The increased noise from the CSK may or not be from the NAPA Silver, but I will never use a Silver again. Although I would not hesitate to use their Gold or Plat line....

 

[Clevy]

Originally Posted By: Tzu
I have the same truck and engine and the best thing I did was switch back from synthetic to conventional. After running synthetic for over 100,000 miles, I figured it was long enough time to see whether it did anything or not. To me, all it did was cost more money. I went with Wix filters instead of AC Delco and it has seemed to help noticeably more. Also, the guys up north like us seem to hear it more than down in Texas or Florida. Come to think of it, in summertime here I almost never hear my truck slap. I think if you could "get on it" now and then that would help as well. I live near a huge wildlife refugee so there are a lot of back roads. The slap reminds me it never left in October...
Originally Posted By: dave123
Originally Posted By: Turk
Could be "Piston Slap". I had it REALLY BAD in my 2000 5.3L Sierra.



I bet it is and same here sounded like it was going to come apart every morning at start up. No filter or oil made it better it just didn't matter.



K. I'm lost. How does synthetic cost more money if you've adjusted the mileage to compensate for using a better oil.
I've got a 99 z71 with a 5.3. I got it with just under 50000km. I used Amsoil signature series for 100000kms when I put a new cam,lifters and pushrods and I never had any piston slap.
It was at that time I stopped buying Amsoil due to cost. I was running 10000km intervals.
Very shortly thereafter piston slap presented itself. At the time of the cam swap nothing on the bottom end was touched. Engine was spotlessly clean without a hint of varnish or any deposits whatsoever.
Since I quit using Amsoil I found that PYB 5w-30 all but eliminated piston slap in the warmer months,and during the winter I used whatever syn was on sale in it,none changed the sound any noticeable amount.
The truck has 280k now. Doesn't consume a drop of oil between changes and has been dynotuned for the cam swap.
So yes Chevy LS v-8 engines may suffer from piston slap however it doesn't affect their longevity whatsoever. Its a nuisance noise at best for a few moments until the pistons warm up.
As far as I'm concerned the ls 5.3 is every bit as durable and has at least as much longevity at the 5.7 it replaced.
In fact I expect they are better because of the roller valvetrain and updated design.

 

[turtlevette]

Originally Posted By: Islandvic
turtlevette, the orientation of my filter is vertical, not horizontal. Are you using the M1 AFE 0w-30? I stopped using M1 in my 5.3 b/c it seemed to make it louder also. What year is your truck?



Yea. Vertical. When I say horizontal I mean vertical. You know what I mean..LOL.

I have the 2002 Suburban 5.3 flex and it makes a nasty racket on M1 0W-30 AFE for about 3 minutes after cold startup only. The Valvoline synthetic 5W-30 in there before wasn't as bad. Whatever they had in it when I bought it used made no slapping sound at all. I thought i had a "good" one. So there is some oil that will quiet the cold slap. I'm not sure what. Probably some [censored] 20W-50 or 10W-30 conventional.

I changed the oil last summer and it got louder since then. Like its cleaning varnish that was filling the piston skirt gaps?

I don't really care about the noise. Sounds like I've got a high dollar diesel in there. A macho factor.

 

[Islandvic]

turtlevette, when it's time to change your oil again, pour 1 1/2 cans of Seafoam in and let idle for 15 min.

Then change the oil. Try 5 quarts Maxlife 10w-40 and 1 quart MMO.

Use a AC Delco PF61 filter.

If it doesnt work, at least it will be a little cleaner.

I had a 2003 Tahoe 5.3 and a 2005 Suburban Z-71 5.3, both had minimal CSK.

I seem to have good luck with the AC Delco filters.

 

[dave123]

Originally Posted By: Islandvic
let me respond to some of the posts

901memphis, yes i am prob more sensitive to the sound!

turtlevette, the orientation of my filter is vertical, not horizontal. Are you using the M1 AFE 0w-30? I stopped using M1 in my 5.3 b/c it seemed to make it louder also. What year is your truck?

Merkava_4 & TSWM, thanks for the input on choices for grades of oil, but i have a multi-OCI stash of 5w-30 and 10w-30 synthtics from G-Oil, NAPA, Castrol Edge Ti and Maxlife Syn Blend (all between $1-$3qt on sale).

Tzu, in my case, Synthetic is cheaper than conventional.

Its time for me to get a new oil drain catch pan. I may drain the oil into a new catch pan, remove and replace the NAPA Silver with a Bosch Premium filter. About 3 months ago I bought 4 to try out b/c I found them for $3.50 each.

I'll report back if the switch to the Bocsh Premium filter changes anything.

The increased noise from the CSK may or not be from the NAPA Silver, but I will never use a Silver again. Although I would not hesitate to use their Gold or Plat line....


When all said and done and you try everything under the sun we will be waiting to hear you say I just learned to live with it good luck.

 

[tswm]

Originally Posted By: turtlevette
I have the 2002 Suburban 5.3 flex and it makes a nasty racket on M1 0W-30 AFE for about 3 minutes after cold startup only. The Valvoline synthetic 5W-30 in there before wasn't as bad. Whatever they had in it when I bought it used made no slapping sound at all. I thought i had a "good" one. So there is some oil that will quiet the cold slap. I'm not sure what. Probably some [censored] 10W-30 conventional.

I don't really care about the noise. Sounds like I've got a high dollar diesel in there. A macho factor.


If I am not mistaken, those GM trucks had push rod engines. If so, 10W30 year round. Really, any dino is good enough in your case, actually preferable. Conventional 5W30 is not a durable multigrade even with SN requirements, so if regular dino 5W30, add a can of BG MOA. Yours doesn't care if it's high SAPS, so no problem using BG MOA.

Or run 100% 10W30 PP (PP 10W30 is a glorified dino, yet has characteristics of "fully" synthetic oil) year round, that should do it.

Don't drink the Dexcoolaid.

 

[steve20]

Originally Posted By: strat81
Originally Posted By: SteveSRT8
Several had carbon knock, that's a very similar sound that many cannot diagnose, super easy to fix.


Indeed, or possibly a combination of typical piston slap with carbon knock.

My 5.3 sees a lot of short trips, idling, and trips in town with speeds generally under 35 mph. When my wife drives it with the kids in the back, it barely goes over 2,000 RPM.

On the odd week that I drive it, I get a bit more aggressive with it and find the engine is quieter at idle and at start up.

It seems my 5.3 really likes to be worked. However, there's not much I can do to help a 5,000 pound SUV stretch its legs when it lives in a suburban environment.



We have the same situation with our 04 Tahoe---with Mom driving it Sometimes I go for 6 months without driving the vehicle---step on it and look at the white cloud out the exhaust! Ours has never knocked hot cold whichever oil or filter. Maybe it was the EASY break-in I gave it

 

[strat81]

Originally Posted By: tswm
Conventional 5W30 is not a durable multigrade even with SN requirements


What evidence do you have to substantiate that claim?

And could you define "durable"?