best oil viscocity/weight....
Thread Starter
Staging Lane
Joined: Jul 2008
Posts: 82
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best oil viscocity/weight.... Got an anoying case of piston slap. Oil really does need to be changed though so no suprises. Im running 5W-30Royal Purple topped off with some mobil 1 
. 67K now and I think its time for some seafoam!!! Should i go with somethign heavier like 10W-30 to quite down the noise? I live in texas so it rarely gets below freezing so what do you guys recomend?
-zach
. 67K now and I think its time for some seafoam!!! Should i go with somethign heavier like 10W-30 to quite down the noise? I live in texas so it rarely gets below freezing so what do you guys recomend?-zach
Thread Starter
Staging Lane
Joined: Jul 2008
Posts: 82
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Im sorry I didn't say it better. Would 10W-30 quite my piston slap or should i get something thicker? The issue is unpleasant noise. I realize it wont magically dissapear!!! but am I on the right track?
-zach
-zach
10W-30 vs. 5W-30, depending on the brand the 10W-30 may actually be thinner at termperature. You need to check the specifications and find out the viscosity at 100 degrees C. That's why I run the German Castrol 0W-30, it has a very high viscosity at 100 degrees C.
Banned
Joined: Jan 2008
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I've ben running Mobil 1 5w/30 . I also use Delco filters in every vehicle i have w/ o any issues whatso ever. T/A w/ 115,000 on it and a 95 GMC sierra w/ 321,000 on the clock and hasnt skipped a beat so i guess the proof is in the pudding(oil)
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Staging Lane
Joined: Jul 2008
Posts: 82
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It will clean out alot of built up grime in my motor reducing overall friction slightly. It certianly will help! Went on that bobistheoil guy site and still couldnt come to a conclusionom what to choose.
Someone told me royal purple was terrible.... ok guys recomend me something that will quite my **** down some and doesnt rob too much power.
Someone told me royal purple was terrible.... ok guys recomend me something that will quite my **** down some and doesnt rob too much power.
The seafoam is a good idea, do it before your oil change. Knocking some carbon off may well reduce noise that is or sounds like piston slap. Where are you in Texas?
I used the RP 10-30 religiously and love it. I just switched to the Euro Castrol Syntec 5-40 and may like it better. I considered the Mobil 1 0-40 with "winter" here. Check out the boboilguy site, it's a great read, and make your call. Any good synthetic + filter every 5k or less will do you right. I've used RP 15-40 and felt it was too thick on startup, though it was nice once running. I am really liking the Syntec so far, it is quieter all the time.
I used the RP 10-30 religiously and love it. I just switched to the Euro Castrol Syntec 5-40 and may like it better. I considered the Mobil 1 0-40 with "winter" here. Check out the boboilguy site, it's a great read, and make your call. Any good synthetic + filter every 5k or less will do you right. I've used RP 15-40 and felt it was too thick on startup, though it was nice once running. I am really liking the Syntec so far, it is quieter all the time.
Teching In
Joined: Jul 2007
Posts: 30
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It will clean out alot of built up grime in my motor reducing overall friction slightly. It certianly will help! Went on that bobistheoil guy site and still couldnt come to a conclusionom what to choose.
Someone told me royal purple was terrible.... ok guys recomend me something that will quite my **** down some and doesnt rob too much power.
Someone told me royal purple was terrible.... ok guys recomend me something that will quite my **** down some and doesnt rob too much power.
The seafoam is a good idea, do it before your oil change. Knocking some carbon off may well reduce noise that is or sounds like piston slap. Where are you in Texas?
I used the RP 10-30 religiously and love it. I just switched to the Euro Castrol Syntec 5-40 and may like it better. I considered the Mobil 1 0-40 with "winter" here. Check out the boboilguy site, it's a great read, and make your call. Any good synthetic + filter every 5k or less will do you right. I've used RP 15-40 and felt it was too thick on startup, though it was nice once running. I am really liking the Syntec so far, it is quieter all the time.
I used the RP 10-30 religiously and love it. I just switched to the Euro Castrol Syntec 5-40 and may like it better. I considered the Mobil 1 0-40 with "winter" here. Check out the boboilguy site, it's a great read, and make your call. Any good synthetic + filter every 5k or less will do you right. I've used RP 15-40 and felt it was too thick on startup, though it was nice once running. I am really liking the Syntec so far, it is quieter all the time.
Thread Starter
Staging Lane
Joined: Jul 2008
Posts: 82
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To the guy that asked what part of Texas I live around houston.... I ended up cheaping out for the first time in awhile. A ******* bearing or something incredibly loud decided to go out the night before the oil change! So went with some castrol synthetic 10W-40. improved hardly at all. Guess I will have to change to change it again soon with some royal.
This syntec 10W-40 stuff any good?
Running M1 10w30 may help with a little thicker film but it won't solve the problem. A little piston slap is normal/acceptable with the LS1 engines.
Seafoam will be no help to you.
Another solution would be to add a cam with fast ramp rates so the valvetrain sewing machine sound drowns out the piston slap noise.
good luck
Seafoam will be no help to you.
Another solution would be to add a cam with fast ramp rates so the valvetrain sewing machine sound drowns out the piston slap noise.
good luck
Seafoam run through the PCV or brake booster in some cases does help with PS but it will come back.
Carbon build up on the piston skirt often produces the slap/knock at cold start. This is why these motors are quiet when new but develop PS as they get more miles thus more carbon build-up. Seafoam can clean this carbon off resulting in less or eliminated PS for a while until it builds back up.
PS is caused by BOTH loose tolerances AND and the short piston skirt designed to reduce rotating mass on these pistons.
Carbon build up on the piston skirt often produces the slap/knock at cold start. This is why these motors are quiet when new but develop PS as they get more miles thus more carbon build-up. Seafoam can clean this carbon off resulting in less or eliminated PS for a while until it builds back up.
PS is caused by BOTH loose tolerances AND and the short piston skirt designed to reduce rotating mass on these pistons.
Joined: Nov 2003
Posts: 6,216
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From: Wichita KS / Rancho San Diego
Carbon build up on the piston skirt often produces the slap/knock at cold start. This is why these motors are quiet when new but develop PS as they get more miles thus more carbon build-up. Seafoam can clean this carbon off resulting in less or eliminated PS for a while until it builds back up.
I usually run GC but decided to put in some cheaper semi-synthetic 5-30 since my winter-spring oil change comes up quicker. Piston slap got much worse. I'm going to go drain it now and replace it with GC.
I have noticed my piston slap get progressively worse in the 5 years and 43,000 miles I've driven the car.
TECH Regular
Joined: Oct 2008
Posts: 406
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From: Maryland
i dont think getting a heavier oil will help 20w50 and a 5w-30 have the same viscosity at operating temps the difference is at start up where a 20w-50 has a really high viscosity (very bad) and 5w-30 is lower (better) try the sea foam but dont go to a heavier oil it will only cause more wear at start up...