Whats this knock?

[IR II IP IDEATH]

Anyone know if this is a common sound or something I should look into?
YouTube - is this knock bad?

[97gtsc]

Piston slap?

[KawaFord]

Are you low on oil? Kind of sounds like a valve tap.

[IR II IP IDEATH]

I dont think so, ill check though.

[Liquifire]

if your oil level is ok....then I would guess piston slap if it does it cold or warm or if it only does it cold until it warms up then it could be bad lifters that need time to pump up. My wifes car has had piston slap in her malibu v6 on both engines that I have had in there. Good luck. I would lean towards what I suggested, but it could possibly be in valves too. Can you tell if it is in more than one cylinder or from one side of the motor or the other?

[IR II IP IDEATH]

nah it only does it for a couple of minutes, and not even all the time, I just dont like hearing noises like that from an 08.

[Boostd1]

Def sounds like piston slap.

[RedGPGT]

try to change oil and add lucas to it...lucas first then add oil like 3q

[toolguy]

If it has not done this new and you are sure it is not normal valve chatter when cold, I would add a bottle of Chevron Techron Fuel system cleaner to your gas tank. Do not use anything else as this stuff works. If that does not solve it, do a top engine clean with GM Top Enginer Cleaner, bought from the dealer. Or a can of BG44, which also removes carbon build up. Changes are you have carbon build up, and one or both of these will fix it.

Piston slap is common on GM engine and there is loads of complaints about it but sometimes it can be fixed using the products mentioned above. Until it returns again after build up and all the crappy ingredients is fuels this days.

[blueguy]

Don't use Lucas? Why not? have you ever had any personal experience with it?

I have...used it on MULTIPLE cars...and it beats any sort of additive to date...that stuff is awesome. It is called Lucas Oil Stabilizer. Great product, less than $10 IIRC.

[BillBoost37]

Piston slap is nearly unheard of on our motors. Actually I've never heard of it.

In researching what I thought was the common 5.3L piston slap on my pickup, I found one guy that suggested looking/checking the exhaust manifold bolts. Presto...found the issue. Might be as simple as a few loose bolts if they've been out for any reason.

[toolguy]

Don't use Lucas? Why not? have you ever had any personal experience with it?

I have...used it on MULTIPLE cars...and it beats any sort of additive to date...that stuff is awesome. It is called Lucas Oil Stabilizer. Great product, less than $10 IIRC.

Not saying Lucas does not work but Chevron Techron is proven, a GM Master Technican friend of mine educated me about it and the GM stuff at the dealer is Chevron. Many are sold out there but GM uses Techron and has tested it works. I will only use Chevron and can recomend it because it does work that is all I mean. I just said nothing else because there are so many out there, liek STP and Gunk, that do not do much.

I have used the Lucas fuel treatment, whatever it was called because a guy swore he got better mileage and all it did on my Jeep was smooth it out, no better mileage seen.