my Mobil 1 experience in GM 5.3L piston slapper

[NHHEMI]

Originally Posted By: KyleBula
I'll cut open the filter tonight. I have never seen a bad napa filter though, but it could happen. Yes, I do open all my filters, atleast for the last few years.

I'm not here to bash Mobil, [censored], I'm the lead operator at work making Synestic 12 for Exxon. We will soon be making Synestic 5 for them in a trial run. I still don't know a fraction about oil like some guys on here, but I do know Exxon keeps me employed in an otherwise poor community.



Was it a Napa Gold or a ProSelect? I have seen the cheaper ProSelect line have cold start issues due to leaky ADBV's. I had issues with the ProSelect line myself on a GM 3.4L. 2 of them had the same cold start noise. Swapped back to an AC and it went away. Same oil.

I would be inclined to believe it was the filter as others have theorized or even some other internal issue that oil actually can help quiet down. Despite your change of oil, and the subsequent lessening of the noise, piston slap in those GM engines just isn't cured by oil. Definitely not to the extent you claim. The piston slap issue is caused by too much clearance between the piston and the sleeve( which is also too short )until the engine warms up causing tolerances to tighten. Oil just can't stop that.

It might be that the PP solved this for you but I find it highly unlikely. Especially since PP and just about every other brand of oil known has been tried and failed to quiet piston slap in GM engines.

 

[demarpaint]

Originally Posted By: KyleBula
I bought my 2000 Silverado 5.3L w/102k miles almost 1 year ago. I knew it had the infamous piston slap when I bought it. I have been on a mission to quiet it ever since. The previous owner always used dino.

After some research I finally decided on Mobil 1 0w30 green cap and a napa gold filter (I use napa filters on everything). I was hoping the thinner oil (when cold) would reach the cylinder walls quick. Well, believe it or not, the piston slap got LOUDER. Not only that, the motor started knocking under load for the first mile or so. This noise was not a tick, it was definatly a knock.

I always warm up my motor on cold days for a minimum of 5 minutes but this never helped with the knock under load. I changed out the Mobil 1 today after only 1100 miles and put in Pennzoil Platinum 5w30 w/ bosch D+ filter, on sale at AA.

Guess what, piston slap is so quiet I had to put my head down by the bumper to hear it. Oh, and that knock under load..... GONE.

Just thought I should share my experience with all of you.


Remember sound means nothing and is all in your head!!!!! LOL J/K Good move! Now the only problem is was it the oil or the filter? My bet is the oil.

 

[KyleBula]

I have seen that site before but never noticed it says 5.7l. Thanks for clarifing that for us daman. So you must have the abnormal engine that doesn't slap. You know, cause GM says piston slap is "NORMAL".

 

[daman]

Originally Posted By: KyleBula
I have seen that site before but never noticed it says 5.7l. Thanks for clarifing that for us daman. So you must have the abnormal engine that doesn't slap. You know, cause GM says piston slap is "NORMAL".

From a quick google search found on various truck web sites...


"i have a 98 silverado z71, also a 350. i have a problem with piston slap also"


"my 5.7 and my dad's 4.3 both do the same thing"

 

[bullwinkle]

After reading that pistonslap link-GM is the one who needs the SLAPPING-the only way to cure that is either bore the engine & go oversize pistons, or sleeve the cylinder & have it bored to match a new piston-anything else is just masking the actual problem. AFE oil is probably the thinnest there is-wonder if a 5W40 or even 15W40 HDEO would make it even quieter, and possibly lessen the consumption?

 

[demarpaint]

Originally Posted By: KyleBula
I have seen that site before but never noticed it says 5.7l. Thanks for clarifing that for us daman. So you must have the abnormal engine that doesn't slap. You know, cause GM says piston slap is "NORMAL".


My guess is piston slap is considered normal when having to actually recall the engines with the "slap" to fix them could possibly put the company out of business. The truth is piston slap is not normal it is a flaw that fortunately doesn't destroy enough engines to warrant any action.

 

[daman]

"my 97 does the same thing, especially when its cold out, sounds like a diesel for a couple of minutes until it warms up. I just let it warm up good before taking off, doesn't seem to affect"

"Piston slap has been a issue for decades. Its the price you pay for parts that get made in mass quantities".

 

[NHHEMI]

Originally Posted By: KyleBula
Uh, I've never heard of the 5.7L having piston slap issues.


Yup some of the early 5.7L LS1( Camaro & Vette )and L31( used in FS vans up to 2003 and the Escalade to 2000 )engines had piston slap issues. It was a problem in many of their V8 and V6 engines actually.

 

[daman]

NO it is not normal never said it was and we all know it here BUT theses GM engines will survive with it.

 

[demarpaint]

I never said you called it normal, I'm just bringing up a point. The mfg was able to safely B_S their way out of fixing the problem that's all.

 

[daman]

Originally Posted By: demarpaint
I never said you called it normal, I'm just bringing up a point. IIRC Ford has a few with piston slap too. The mfg was able to safely B_S their way out of fixing the problem that's all.

I know you didn't D just throwing it out there ....

yes other manufactures had it too and it wasn't fully cured with oil selection.

 

[NHHEMI]

It should be noted that for the most part GM solved the piston slap issue by the 2004/2005 model year. At least for the truck V8's. I seem to recall they used a different/longer sleeve to solve it? Maybe a different piston material /deasign as well? Can't recall the exact details.

Some folks still complain about it in newer vehicles but I have my doubts it is the exact same issue as they are a small group vs what it was when this was a very common issue.

FWIW I had a 2005 Silverado with the HO 5.3L( aluminum block 310 HP version not the standard 295 HP cast iron block )and a 2007(NBS ) with the 315 HP cast 5.3L and I had zero piston slap issues. In my time on the Chevy truck sites I did not read about piston slap being an issue for people from 05 on. 99-03/04 seemed to be the main time line for the problem.

 

[KyleBula]

Well, I cut open the filter and examined it thoroughly. I can't see any flaws and probably should've left it on the truck. I honestly never thought it was the filter til someone mentioned it on here.

Also, let me clear up somethings. I never said my piston slap was gone, I simply said I put my head down by the bumper to hear it. I just fired up the truck that has been sitting in my cold garage, shut my truck door and I can no longer here the slap from inside my truck. I have to believe that is due to the oil.
I drove it out of my garage and down the road COLD, I DO NOT have the knock anymore. This was all done less than 5 minutes ago.

I'm sure there will be none believers, but I have no reason to lie. I just wanted to share my experience and I hope some of you have similar luck with PP.

 

[demarpaint]

I thought the oil had something to do with it. It has been reported by many of us that some oils are quieter in our applications than others. Looks like you found your new favorite oil! That's good news!

 

[OVERKILL]

Originally Posted By: NHHEMI
It should be noted that for the most part GM solved the piston slap issue by the 2004/2005 model year. At least for the truck V8's. I seem to recall they used a different/longer sleeve to solve it? Maybe a different piston material /deasign as well? Can't recall the exact details.

Some folks still complain about it in newer vehicles but I have my doubts it is the exact same issue as they are a small group vs what it was when this was a very common issue.

FWIW I had a 2005 Silverado with the HO 5.3L( aluminum block 310 HP version not the standard 295 HP cast iron block )and a 2007(NBS ) with the 315 HP cast 5.3L and I had zero piston slap issues. In my time on the Chevy truck sites I did not read about piston slap being an issue for people from 05 on. 99-03/04 seemed to be the main time line for the problem.


They coated the skirts in Teflon like Ford does.

The reason they slap is the loose piston-to-bore clearance. The blocks are bulk-bored and the pistons are bulk-fitted. There is no matching of pistons to bores. So some engines end up with clearances on the loose side and these ones slap. Some don't, and so they don't.

The issue is compounded by the short pistons with very short skirts as well.

 

[daman]

Originally Posted By: demarpaint
I thought the oil had something to do with it. It has been reported by many of us that some oils are quieter in our applications than others. Looks like you found your new favorite oil! That's good news!

Some times changing oil's and or viscosity's did help some...but to totally eliminate it no.

 

[NHHEMI]

Originally Posted By: KyleBula
Well, I cut open the filter and examined it thoroughly. I can't see any flaws and probably should've left it on the truck. I honestly never thought it was the filter til someone mentioned it on here.

Also, let me clear up somethings. I never said my piston slap was gone, I simply said I put my head down by the bumper to hear it. I just fired up the truck that has been sitting in my cold garage, shut my truck door and I can no longer here the slap from inside my truck. I have to believe that is due to the oil.
I drove it out of my garage and down the road COLD, I DO NOT have the knock anymore. This was all done less than 5 minutes ago.

I'm sure there will be none believers, but I have no reason to lie. I just wanted to share my experience and I hope some of you have similar luck with PP.


The flaw would be a faulty ADBV.

 

[NHHEMI]

Originally Posted By: OVERK1LL
Originally Posted By: NHHEMI
It should be noted that for the most part GM solved the piston slap issue by the 2004/2005 model year. At least for the truck V8's. I seem to recall they used a different/longer sleeve to solve it? Maybe a different piston material /deasign as well? Can't recall the exact details.

Some folks still complain about it in newer vehicles but I have my doubts it is the exact same issue as they are a small group vs what it was when this was a very common issue.

FWIW I had a 2005 Silverado with the HO 5.3L( aluminum block 310 HP version not the standard 295 HP cast iron block )and a 2007(NBS ) with the 315 HP cast 5.3L and I had zero piston slap issues. In my time on the Chevy truck sites I did not read about piston slap being an issue for people from 05 on. 99-03/04 seemed to be the main time line for the problem.


They coated the skirts in Teflon like Ford does.

The reason they slap is the loose piston-to-bore clearance. The blocks are bulk-bored and the pistons are bulk-fitted. There is no matching of pistons to bores. So some engines end up with clearances on the loose side and these ones slap. Some don't, and so they don't.

The issue is compounded by the short pistons with very short skirts as well.


I hadn't heard about the teflon. I am pretty sure they used longer sleeves to help stop it by the 05 model year. I am aware of the clearance and short skirt issue. Posted about it earlier.

 

[dave123]

Originally Posted By: NHHEMI
Originally Posted By: KyleBula
Well, I cut open the filter and examined it thoroughly. I can't see any flaws and probably should've left it on the truck. I honestly never thought it was the filter til someone mentioned it on here.

Also, let me clear up somethings. I never said my piston slap was gone, I simply said I put my head down by the bumper to hear it. I just fired up the truck that has been sitting in my cold garage, shut my truck door and I can no longer here the slap from inside my truck. I have to believe that is due to the oil.
I drove it out of my garage and down the road COLD, I DO NOT have the knock anymore. This was all done less than 5 minutes ago.

I'm sure there will be none believers, but I have no reason to lie. I just wanted to share my experience and I hope some of you have similar luck with PP.


The flaw would be a faulty ADBV.



Not needed on a 5.3L

 

[KyleBula]

Not sure about the ADBV, it looks ok and this is a Napa Gold with the reddish silicon ADBV. I did still have about 4-6 oz. of oil in it when I cut it open and its been draining for the last few hrs.