Our Community is 705,000 Strong. Join Us.


POLL: Synthetic vs Dyno oil to quiet Piston Slap


Suprteck
07-01-2004, 11:16 AM
I am some what new to the group and hope I am doing this correctly.

I own a 2002 Silverado Z71 5.3 L. I have the piston slap/knock noise.
I switched over to Mobil 1 Synthetic 5w30 at the 9000 mile mark and now have aprox 36000 miles on the truck.

I have searched the threads looking for information on anything that might help quiet the noise in any way. I picked up some information on the web also , some say if you use Mobil 1 Synthetic 10w40 it helps a lot.
I talked with many dealerships and get mixed opinions,some say use Pro Long, some say Mobil 1, some say Engine Restore, and some say Dyno oil is better then all those but all say that using the 10w40 instead of the 5w30 will NOT void any warranty that the only neg. is I will notice a slight gas mil. diff.
But the funny thing is when I ask them if they have personaly used these products or know someone that has and heard a differance they say NO. Just that they heard they work. Except one who uses Mobil 1 5w30 and says he THINKS it makes a diff.

Any way considering all the people here I figured this would be a wealth of information.

So has any one tried different oils and what type and brand seems to help the most.

Or has anyone found any thing at all to help quiet the embarssing sound.

Thanx for all comments

Jimmiz71
07-01-2004, 02:29 PM
I have 80k on my truck and use Valvoline High Mileage 5w30 with one quart of Rinslone additive with every change every 2500 miles, the Piston slap in my truck is very faint but more noticable when the engine is cold then it dissapears once the oil circulates. I thought about switching to synthetic but everyones opinions were mixed about it, I change my oil so frequently that it really wouldnt make that much of a difference.
-Jimmy

Puffnstuff
07-01-2004, 03:48 PM
I've heard different reasons for the noise including a build up of carbon on the pistons. I had a 99 with the 5.3 and twice it made that knocking sound when it had very low miles on it using the factory oil. On my first change I went to mobil 1 5w-30 with the acdelco pf59 filter and never heard that sound again. I had the truck until it had 30k on it and it ran fine with the mobil 1 in it. I did have another problem that a superchips tuner took care of but no more knocking sounds. Just remember that your mileage may vary and what works for one person might not work for you. Synthetic oil has a high detergent content so it will clean up your engine.

jerrylittle
07-02-2004, 08:21 AM
I am some what new to the group and hope I am doing this correctly.

I own a 2002 Silverado Z71 5.3 L. I have the piston slap/knock noise.
I switched over to Mobil 1 Synthetic 5w30 at the 9000 mile mark and now have aprox 36000 miles on the truck.

I have searched the threads looking for information on anything that might help quiet the noise in any way. I picked up some information on the web also , some say if you use Mobil 1 Synthetic 10w40 it helps a lot.
I talked with many dealerships and get mixed opinions,some say use Pro Long, some say Mobil 1, some say Engine Restore, and some say Dyno oil is better then all those but all say that using the 10w40 instead of the 5w30 will NOT void any warranty that the only neg. is I will notice a slight gas mil. diff.
But the funny thing is when I ask them if they have personaly used these products or know someone that has and heard a differance they say NO. Just that they heard they work. Except one who uses Mobil 1 5w30 and says he THINKS it makes a diff.

Any way considering all the people here I figured this would be a wealth of information.

So has any one tried different oils and what type and brand seems to help the most.

Or has anyone found any thing at all to help quiet the embarssing sound.

Thanx for all comments I have a 98 with a new motor because the dealer burnt up the original. Right from day one the new motor out of the crate made a knocking noise sounds like a rod. I have used moble one in it from day one also. I used 5-30 and now 15-50 I now have 25,000 on the motor and it is still there.

Faze2183
07-04-2004, 07:59 AM
i have been running royal purple 10w30 for the winter time, and ive never had any kinda problems running royal purple..... my milage has gone up, it doesnt break down as fast as most oils do, u will maybe notice some hp diffrences, over all greatest oil to use, and now that its summer time im usin 20w50, btw the oil is purple just in case no one knew that already heh

btw: i change my oil every 5k miles and use fram x2 oil filter and i dont think i could ever use any other oil im very happy and guess what its true Synthetic......

try royal purple suprteck, you will not go wrong and u can pick up that stuff at napa auto parts, ill recomond buyin a case cuz its cheaper

jerrylittle
07-04-2004, 10:00 AM
i have been running royal purple 10w30 for the winter time, and ive never had any kinda problems running royal purple..... my milage has gone up, it doesnt break down as fast as most oils do, u will maybe notice some hp diffrences, over all greatest oil to use, and now that its summer time im usin 20w50, btw the oil is purple just in case no one knew that already heh

btw: i change my oil every 5k miles and use fram x2 oil filter and i dont think i could ever use any other oil im very happy and guess what its true Synthetic......

try royal purple suprteck, you will not go wrong and u can pick up that stuff at napa auto parts, ill recomond buyin a case cuz its cheaper
IS this royal blue synthetic? If so who makes it?

Faze2183
07-04-2004, 10:15 AM
yes it is synthetic its almost pure synthetic, its made by www.royalpurple.com check them out u will like them alot

HDChvyTrk
07-04-2004, 06:44 PM
I would suggest synthetic oil but i do not believe it will help your noise. The noise in the 4.8, 5.3, and some 6.0 engines is the smae noise the firebirds and camaro's had when the 5.7 LS1 was new and it is PISTON SLAP. All these motors use next generation hypereutic pistons.
What Hypereutic is in a nut shell: A piston is a round piece of aluminium with a large steal pin ththrought the center of it. A piston also has a SKIRT which is designes to help offset torsional stress applied by the rod as the piston travels upand down the cylinder. When the round piston heats up durring start up, it expands. It expands different amounts because the area were the pin is is much thicker thus creating a slightly ovalized piston. Most engines use a bore that is slightly larger then the piston to accomodate this mishape.
A while ago some one got he great idea to make a piston that was an oval cold and would become more round as it heated. Sounds great in theory and it works fine in the aftermarket but with production tolerances in place for assembly you end up with pistons that have a little more play in the skirt area then they should. This then dissapears when the engine has warmed up.
No oil will make this sound go wawy. Heavier oil will muffle it. Lighter oil will shorten the time you hear it as it travels through the motor faster.

jerrylittle
07-04-2004, 07:37 PM
I would suggest synthetic oil but i do not believe it will help your noise. The noise in the 4.8, 5.3, and some 6.0 engines is the smae noise the firebirds and camaro's had when the 5.7 LS1 was new and it is PISTON SLAP. All these motors use next generation hypereutic pistons.
What Hypereutic is in a nut shell: A piston is a round piece of aluminium with a large steal pin ththrought the center of it. A piston also has a SKIRT which is designes to help offset torsional stress applied by the rod as the piston travels upand down the cylinder. When the round piston heats up durring start up, it expands. It expands different amounts because the area were the pin is is much thicker thus creating a slightly ovalized piston. Most engines use a bore that is slightly larger then the piston to accomodate this mishape.
A while ago some one got he great idea to make a piston that was an oval cold and would become more round as it heated. Sounds great in theory and it works fine in the aftermarket but with production tolerances in place for assembly you end up with pistons that have a little more play in the skirt area then they should. This then dissapears when the engine has warmed up.
No oil will make this sound go wawy. Heavier oil will muffle it. Lighter oil will shorten the time you hear it as it travels through the motor faster.
hmmmm I would have to bag your pardon. I have a brand new 5.7 LSI 98 and it does it when just started and even after hours of running it. I know someone who has a 5.3 same thing does not matter if it is cold or hot. I am told there is nothing to worry about it will still last just as long and not come apart. My motor was a crate motor from chevy not a reman from chevy. Still under warranty.

HDChvyTrk
07-04-2004, 09:33 PM
The more slop there is between the piston and cylinder wall the more pronounced the noise will be and it may not go completly away but I bet it is louder when it is cold then when it is warmed up??

jerrylittle
07-04-2004, 09:40 PM
The more slop there is between the piston and cylinder wall the more pronounced the noise will be and it may not go completly away but I bet it is louder when it is cold then when it is warmed up??
Hard to say it seems to change a bit sometimes it seems so when it is cold sometimes it seems so when it is warm? I probably wont get much life out of it huh? I used synthetic moble 1 from day one I gave to the dealer when they installed the motor.

HDChvyTrk
07-04-2004, 09:49 PM
I am not sure about that, I know two people who have 90k plus miles and, minus the noises, there trucks still run fine? kind of funny that these motors have these noises but seem to be some of the best performing engines out their. Just a little disconcerting to start your 30k-35k dollar vehicle and here theose obnocious sounds huh?

Dale fan
07-05-2004, 01:46 AM
I know when I switched to Mobil 1 from dino in my 6.0 the slap is louder but mine has always went away within a minute. Sounds like lifter's ticking.

Suprteck
07-05-2004, 09:34 AM
Thanks for the responses so far.

I tried the 10w40 thing out, I went and got the AC delco filter from the dealership close by and asked them about the Engine Restorer idea. They said that some people have tried it but they would highly recomend NOT using it or any additive. They said to try using Valvoline Max Life 10w40 dino, so i went with that.

After i changed the oil and filter i noticed the knock was now louder and more pronounced and never went away no matter how hot I got the motor. But now it sounded like one piston knocking instead of multiple. Then came the driving test, there are some back road long under passes around here that you can realy get a good listen to what your truck sounds like outside the cab as you are driving through them, as i drove and after transmission shifts into second gear i would release off the accelerator and get a louder more noticable diesel sound like valves clattering but it was the piston slap. So with using a thicker oil the piston slap in my vehicle became worse.

At least with Mobil 1 5w30 synthetic by the time i get to the store and if i leave the truck on to listen there is no knocking that is noticable at idle until i turn it off and restart it, the diesel sound is still there while driving but is slightly quieter..

I love the looks of my truck and to date 2 yrs old and 36000 miles i have not had any problems worth noting but this constant knocking piston slap diesel sound is just killing me. I HATE THIS MOTOR. TRUELY HATE IT.

SIDE NOTE

I talked with a real reputable well known auto machine shop out here in CA. They build custom motors for pro racers.
and could get new pistons and cylinders worked on the whole works for about 3000.00, he said i should think about it and that its cheaper then buying a new truck but is it a good idea, I think it would just open up a pandoras box.

thanks again for the comments so far, i am very interested in hearing more.


MY TRUCK:
02 Siverado Z71, 5.3L
4" Rancho Suspension Lift
Nitto LT305's on Weld Racing Rims
Flowmaster 70 series Dual Cat Back

jerrylittle
07-05-2004, 10:09 AM
Thanks for the responses so far.

I tried the 10w40 thing out, I went and got the AC delco filter from the dealership close by and asked them about the Engine Restorer idea. They said that some people have tried it but they would highly recomend NOT using it or any additive. They said to try using Valvoline Max Life 10w40 dino, so i went with that.

After i changed the oil and filter i noticed the knock was now louder and more pronounced and never went away no matter how hot I got the motor. But now it sounded like one piston knocking instead of multiple. Then came the driving test, there are some back road long under passes around here that you can realy get a good listen to what your truck sounds like outside the cab as you are driving through them, as i drove and after transmission shifts into second gear i would release off the accelerator and get a louder more noticable diesel sound like valves clattering but it was the piston slap. So with using a thicker oil the piston slap in my vehicle became worse.

At least with Mobil 1 5w30 synthetic by the time i get to the store and if i leave the truck on to listen there is no knocking that is noticable at idle until i turn it off and restart it, the diesel sound is still there while driving but is slightly quieter..

I love the looks of my truck and to date 2 yrs old and 36000 miles i have not had any problems worth noting but this constant knocking piston slap diesel sound is just killing me. I HATE THIS MOTOR. TRUELY HATE IT.

SIDE NOTE

I talked with a real reputable well known auto machine shop out here in CA. They build custom motors for pro racers.
and could get new pistons and cylinders worked on the whole works for about 3000.00, he said i should think about it and that its cheaper then buying a new truck but is it a good idea, I think it would just open up a pandoras box.

thanks again for the comments so far, i am very interested in hearing more.


MY TRUCK:
02 Siverado Z71, 5.3L
4" Rancho Suspension Lift
Nitto LT305's on Weld Racing Rims
Flowmaster 70 series Dual Cat Back
Wow! sounds a lot like mine :) I told the chevy dealer and one said that many of these trucks do it. He said it will not come apart on you don't worry. When mine was new the whole valve train would make noise when it got hot almost like a diesel. Since it broke in that went away. Just noise that knocking that sounds like it is coming from the oil pan. huh? O'well I guess. Still under warranty for another 25k.

HDChvyTrk
07-05-2004, 01:20 PM
One thing to remember when comparing dino to syn. is syn. will get closer to the actuall weights then dyno oil will

Suprteck
07-08-2004, 09:17 AM
For any one interested ...
just cause im obsessed and have too much time on my hands at the moment...LOL


As you read in my previous post i tried the Valvoline 10w40 max life oil with worse results.

the oils "I" have tried so far

Mobil Drive Clean dino 5w30 and 10w30 not bad but still loud

Valvoline 5w30 dino (loud)(doesnt go away)

Valvoline 10w30 dino (loud)(doesnt go away)

(Valvoline 10w40 max life dino (loudest)(doesnt go away)

Mobil 1 Synthetic 5w30 (better )(does go away, but can still hear it while driving ) But gets better as more miles are put on the oil.

Mobil 1 10w30 (best) Initial knock at start up goes away the fastest) and diesel sound while driving least noticable) And gets better as more miles accumulate on the oil.
Why I have no idea, i would think 5w30 would be best.

Now im a big Valvoline fan, always used Valvoline oil in almost all my vehicles in the past 25 yrs . But in my truck Mobil 1 does seem to quiet the noise to some degree. And for me any positive change is welcomed.

Has any one tried ProLong or Engine Restorer additives??

Nave
08-17-2004, 01:28 AM
That's just wrong of GM not to take care of thei problem..Just wrong..

Faze2183
08-17-2004, 04:04 AM
well when i get my 01 chevy with the 6.0 i didnt notice anything when i test drove it but when i get it ill see if the royal purple helps any or not and ill try the diff grades and etc.....and ill keep an eye out

silveradoman
08-21-2004, 06:12 PM
I have a 99 Silverado 5.7L Vortec, it has piston slap noise also. I use Castrol 20W-50 and I am thinking of switching to a Castrol Magnatek, itīs supposed to stick better to the parts when the engine sit overnight. Since I converted the truck to run on propane, every oil change I notice that it comes out cleaner, so the noise has gone down with a cleaner engine. It does sound like the rods are making the noise.

zed332l
09-09-2004, 07:04 PM
Bought my 2k z71 appox. 2 years ago @ 44k. noticed noise after it sat over a 3 day weekend shortlt there after. . Changed mobil 1 10w-30 with the mobil 1 filter for about 3 oil changes (twice a year). still had the noise on startup first thing in the morning. Last oil change @ approx. 52k I went with royal purple 10w30 with the mobil 1 filter (designed to work with syn. oils). Have not heard the noise since...picked up almost 1 mpg also. I will stay with it....Lets see what the PA winters do to it. OBTW mobil 1 on sale in this area approx. 4.69 on sale. Royle purple 5.99 on sale times 6. mobil 1 filter approx. 11.00.

again 2000 silverado
1500 4x4 with the 5.3 engine and 4l60e trans. first truck & I love it.
I will be switching to all royle purple ( all diff./ transmission/ transfer case before winter.

LT-Z71drvr
10-16-2004, 09:24 PM
zed-
how long do you plan on going between oil changes??
I have heard of leaving the oil in there for 12000 miles
or more??!!
:confused:

zed332l
10-21-2004, 07:50 AM
Bought my 2k z71 appox. 2 years ago @ 44k. noticed noise after it sat over a 3 day weekend shortlt there after. . Changed mobil 1 10w-30 with the mobil 1 filter for about 3 oil changes (twice a year). still had the noise on startup first thing in the morning. Last oil change @ approx. 52k I went with royal purple 10w30 with the mobil 1 filter (designed to work with syn. oils). Have not heard the noise since...picked up almost 1 mpg also. I will stay with it....Lets see what the PA winters do to it. OBTW mobil 1 on sale in this area approx. 4.69 on sale. Royle purple 5.99 on sale times 6. mobil 1 filter approx. 11.00.

again 2000 silverado
1500 4x4 with the 5.3 engine and 4l60e trans. first truck & I love it.
I will be switching to all royle purple ( all diff./ transmission/ transfer case before winter.

Still plan on keeping the same schedule I been using for 25 years. Oil/filter change twice a year. I only put approx. 8-10K a year on my vechicles.

LT-Z71drvr
10-21-2004, 10:42 PM
Cool.
Might as well keep it changed just like normal since the
price is'nt that much more.
Might hafta consider this myself.

ladybailbonds
11-06-2005, 01:34 PM
My 2000 Silverado has 249,000 miles on it. Other than routine maintenance, I've had to change the Fuel pump and the alternator. I have the same ticking noise when first started, but goes away after 30-45 seconds of starting. Keeping my fingers crossed that the engine doesn't blow up here soon.

HanibalTheCannibal
11-06-2005, 08:16 PM
I have a 2001 LS Ext cab 5.3 vortec with 43K on it. After reading these threads a while back, I listened and I did notice a "very faint" lifter tick in the morning.
I switched to Mobil1 Extended Performance 5W30 and a Mobil1 Synthetic Filter, and the noise is gone.

Come to think of it, almost any make, model engine (with low miles)will sound kind of "dry" in the morning, dont they?

BlenderWizard
11-06-2005, 08:36 PM
I have a 2001 LS Ext cab 5.3 vortec with 43K on it. After reading these threads a while back, I listened and I did notice a "very faint" lifter tick in the morning.
I switched to Mobil1 Extended Performance 5W30 and a Mobil1 Synthetic Filter, and the noise is gone.

Come to think of it, almost any make, model engine (with low miles)will sound kind of "dry" in the morning, dont they?

That's been my experience, but everyone seems to think it's a new thing with the Gen III small blocks... :screwy:

jonathansjeep
05-30-2009, 11:21 PM
My 02 Avalanche has had this noise for a very long time. It has 230,000 miles and has never had a problem!!!! Apparantly almost all GM's with the 5.3s have this sound. I recently had the cash to buy another engine and swap it in so I could do a full inspection because I myself was concerned about the reliability. I couldn't believe that there was virtually no wear at all on this engine, I firmly believe it could have reliably performed for another 100,000 miles. All the bearings were flawless, rings intact, valves weren't chipped, none of the usual things you would certainly find on a typical chevy 350 with even just 150k miles. I wouldn't worry about it, you can spend the extra cash if you want on the mobil 1 baloney but ive used the plain ole cheap quaker state 5-30 every 4000 miles or so and there wasn't a DROP of sludge anywhere on this engine. I was and am still astounded. GM finally got an engine right!

PS buy another 5.3 and fiddle with it, I bought a replacement motor with 80,000 miles with 6 month warranty complete top to bottom with harness for $375 and can do that again any day of the week.

jonathansjeep
05-30-2009, 11:26 PM
all it is is the lifters!!!!! Does anybody out there realize hydraulic roller lifters have pounds and pounds of pressure that pushes on them constantly when the engine is turned off pushing the oil out of it?? It takes on a few seconds and it goes away because it must fill back up with oil. GM did take this into account when they moved to hydraulic rollers. Dont like the sound I suggest you swap out to solid rollers and pull the valve covers off every saturday to adjust the lash....

GMMerlin
05-31-2009, 02:14 AM
My 02 Avalanche has had this noise for a very long time. It has 230,000 miles and has never had a problem!!!! Apparantly almost all GM's with the 5.3s have this sound. I recently had the cash to buy another engine and swap it in so I could do a full inspection because I myself was concerned about the reliability. I couldn't believe that there was virtually no wear at all on this engine, I firmly believe it could have reliably performed for another 100,000 miles. All the bearings were flawless, rings intact, valves weren't chipped, none of the usual things you would certainly find on a typical chevy 350 with even just 150k miles. I wouldn't worry about it, you can spend the extra cash if you want on the mobil 1 baloney but ive used the plain ole cheap quaker state 5-30 every 4000 miles or so and there wasn't a DROP of sludge anywhere on this engine. I was and am still astounded. GM finally got an engine right!

PS buy another 5.3 and fiddle with it, I bought a replacement motor with 80,000 miles with 6 month warranty complete top to bottom with harness for $375 and can do that again any day of the week.

Hi and welcome to Af...this thread is 5 years old.....lets not keep digging up the dead

Add your comment to this topic!