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Old 12-29-2012, 04:12 PM   #1
twistedmentality
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Default Lucas Oil help piston slap ?

will lucas oil stabilizer help cold start up piston slap ?

when its cold outside 40*f or colder my engine sounds terrible till it warms up. ive read countless posts about piston slap and the noise being quite common.

ive used lucas oil stabilizer in previous vehicles and was wondering if it would be good for the soob.

thank you.
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Old 12-29-2012, 04:20 PM   #2
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are you serious? do you know how thick that stuff is? please dont buy that crap.
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Old 12-29-2012, 04:23 PM   #3
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Nope. Piston slap is not a question of oil viscosity. It's a matter of the tolerance between the cylinder wall and the piston being great enough to allow a miniscule amount of play until heat expansion occurs.

You'd be better off with a block/oil pan heater.
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Old 12-29-2012, 07:23 PM   #4
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Or, simply don't worry about it and just drive your car.... And like someone else said, DO NOT USE the lucas oil stabilizer, just don't...

My 96 2.2 impreza wagon has had piston slap since 121k miles and it has almost 203,000 right now... So, really no need to get in a bunch about this piston slap, ok
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Old 12-29-2012, 07:53 PM   #5
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Quote:
Originally Posted by cal_look_zero View Post
Nope. Piston slap is not a question of oil viscosity. It's a matter of the tolerance between the cylinder wall and the piston being great enough to allow a miniscule amount of play until heat expansion occurs.

You'd be better off with a block/oil pan heater.

actually it IS a question of viscosity...as in the oil being too thin and not providing a thick enough film on the cyl walls

this is why using MOST 5w30 oils is a bad idea as they all shear to 20wt and can make this issue worse

i would suggest using a different NOT 5w30 oil
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Old 12-29-2012, 08:25 PM   #6
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40F? meh

Don't worry.
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Old 12-30-2012, 02:34 AM   #7
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Quote:
Originally Posted by Uncle Scotty View Post

actually it IS a question of viscosity...as in the oil being too thin and not providing a thick enough film on the cyl walls

this is why using MOST 5w30 oils is a bad idea as they all shear to 20wt and can make this issue worse

i would suggest using a different NOT 5w30 oil
Piston slap is not a product of oil viscosity and any oil cold viscosity had little or nothing to do with the weight it changes to at temp. Oil does not shear down to a lower viscosity when it warms, it just changes due to thermal properties of the oil. If a 30 weight warm oil has properties of a 20 weight then the oil is to blame. Shearing is a result of the oil/additive package not bring up to the conditions.
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Old 12-30-2012, 03:13 AM   #8
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Originally Posted by RaceFaceXC View Post
Piston slap is not a product of oil viscosity and any oil cold viscosity had little or nothing to do with the weight it changes to at temp. Oil does not shear down to a lower viscosity when it warms, it just changes due to thermal properties of the oil. If a 30 weight warm oil has properties of a 20 weight then the oil is to blame. Shearing is a result of the oil/additive package not bring up to the conditions.
so....the dozen or so subarus that i have encountered that had piston slap on cold start....that i recommended a BETTER, non 5w30 oil to the owner....who then changed the oil and had their piston slap on cold start STOP were just having dilusions and hallucinations


yeah......and i dont think you really understand what is and isnt causing this issue.....or anything about motor oils, either


oh yeah...the other thing is carbon build up on the rings....some seafoan and/or upper cylinder lubricant can help, too
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Old 12-30-2012, 09:14 AM   #9
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Originally Posted by Uncle Scotty View Post
so....the dozen or so subarus that i have encountered that had piston slap on cold start....that i recommended a BETTER, non 5w30 oil to the owner....who then changed the oil and had their piston slap on cold start STOP were just having dilusions and hallucinations

yeah......and i dont think you really understand what is and isnt causing this issue.....or anything about motor oils, either
Ha345
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Old 12-30-2012, 12:25 PM   #10
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Quote:
Originally Posted by Uncle Scotty View Post
so....the dozen or so subarus that i have encountered that had piston slap on cold start....that i recommended a BETTER, non 5w30 oil to the owner....who then changed the oil and had their piston slap on cold start STOP were just having dilusions and hallucinations


yeah......and i dont think you really understand what is and isnt causing this issue.....or anything about motor oils, either


oh yeah...the other thing is carbon build up on the rings....some seafoan and/or upper cylinder lubricant can help, too
You're wrong.

I've had piston slap forever on my Forester. Everytime I switched to a thicker oil such as 5W-40 or 10W-40 from 5W-30, it's gotten WORSE.
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Old 12-30-2012, 12:35 PM   #11
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Quote:
Originally Posted by Uncle Scotty View Post
actually it IS a question of viscosity...as in the oil being too thin and not providing a thick enough film on the cyl walls

this is why using MOST 5w30 oils is a bad idea as they all shear to 20wt and can make this issue worse

i would suggest using a different NOT 5w30 oil
Incorrect sir. If that were the case, piston slap would be a symptom of warm weather where the oil would be less dense upon startup.

The colder it is, the slower the molecules in the oil move, thus making it more dense (Physics 101) and therefore creating a condition resembling higher viscosity. If it were a condition of oil viscosity, piston slap would get worse as the engine got warmer. Not to mention that turboless Subarus really don't tend to shear oil (I ran crap oil for 3k miles on my old 2.2 that I flogged and it still read as a 5w30 when I sent it to Blackstone)

As I said before, it's a condition of tolerances between the cylinder wall and the piston; More so post 1996 after Subaru changed the length of the piston skirts to reduce rotating mass and therefore created less surface area to mate to the cylinder wall. Don't take my word for it though...

Quote:
The infamous "piston slap"

Summary

Description: Clicking, tapping, or knocking noise eminating from the engine after a cold start. The noise lasts until the engine is warmed, usually 5-15 minutes. The sound may be heard in the passenger compartment.
Affects: 2.5L DOHC engine, particularly from 1997 to 1999.
Diagnosis: The pistons are engineered for operation at temperature. In an effort to save weight in the engine, the piston skirts were shaved down. When the pistons are cool, however, they do not have sufficient contact with the cylinder to keep from 'slapping' or rattling against the cylinder sides. At temperature, due to thermal expansion, the pistons match up properly with the cylinder and do not rattle.
Reported solutions: In some cases, SOA has rebuilt the engine short block, while in others SOA prescribed "countermeasure pistons" with longer skirts that do not slap. Most dealers will initially state the sound is "normal."
Detrimental effects: SOA has said that the noise causes no engine problems or abnormal engine wear; Subaru engine expert CCR Engines of Colorado has said that the engine may experience a 10% reduction in life.
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Old 12-30-2012, 01:11 PM   #12
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Originally Posted by cal_look_zero View Post

Incorrect sir. If that were the case, piston slap would be a symptom of warm weather where the oil would be less dense upon startup.

The colder it is, the slower the molecules in the oil move, thus making it more dense (Physics 101) and therefore creating a condition resembling higher viscosity. If it were a condition of oil viscosity, piston slap would get worse as the engine got warmer. Not to mention that turboless Subarus really don't tend to shear oil (I ran crap oil for 3k miles on my old 2.2 that I flogged and it still read as a 5w30 when I sent it to Blackstone)
The 253 shears the crap out of some oils, M1 specifically. The oil weight alone is not a great indicator of how much it has sheared. There is another value, some acronym like HTHP or something, that I cannot remember right now that it's better representation of how much it had sheared. And the reason why piston slap goes away as things warm up is because of thermal expansion of the piston. But I dirges, to avoid turning this into a internet battle of science and experience vs. experience
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Old 12-30-2012, 01:32 PM   #13
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My '91 Volvo started slapping at 50K miles. It's now at 240K and the slapping is a just a little bit worse. Just drive sensibly when cold and ignore the slap - as long as it goes away when the engine warms up.

Last edited by OldGoat38; 12-30-2012 at 01:38 PM.
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Old 12-30-2012, 01:47 PM   #14
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Originally Posted by OldGoat38 View Post
My '91 Volvo started slapping at 50K miles. It's now at 240K and the slapping is a just a little bit worse. Just drive sensibly when cold and ignore the slap - as long as it goes away when the engine warms up.
There are also many examples of high mileage Subarus that have/had piston slap for many of those miles. However, no piston slap is obviously better for the longevity of the engine and the increase wear on the skirts means that aluminum is going into the oil. Unfortunately it's an expensive problem to fix.... errr I mean just pour some 20w30 in. Apparently problem fixed.
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Old 12-30-2012, 02:19 PM   #15
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Quote:
Originally Posted by RaceFaceXC View Post
The 253 shears the crap out of some oils, M1 specifically. The oil weight alone is not a great indicator of how much it has sheared. There is another value, some acronym like HTHP or something, that I cannot remember right now that it's better representation of how much it had sheared. And the reason why piston slap goes away as things warm up is because of thermal expansion of the piston. But I dirges, to avoid turning this into a internet battle of science and experience vs. experience
Well that's because M1 is crap, and I wouldn't put it in my 73 ford.

But you voiced what I was saying, how it's a matter of hard parts and not oil that is the cause for piston slap. Damn FHI and their reduction of rotating mass!!! -shakes fist-
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Old 12-30-2012, 03:01 PM   #16
twistedmentality
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The infamous "piston slap"

Summary

Description: Clicking, tapping, or knocking noise eminating from the engine after a cold start. The noise lasts until the engine is warmed, usually 5-15 minutes. The sound may be heard in the passenger compartment.
Affects: 2.5L DOHC engine, particularly from 1997 to 1999.
Diagnosis: The pistons are engineered for operation at temperature. In an effort to save weight in the engine, the piston skirts were shaved down. When the pistons are cool, however, they do not have sufficient contact with the cylinder to keep from 'slapping' or rattling against the cylinder sides. At temperature, due to thermal expansion, the pistons match up properly with the cylinder and do not rattle.
Reported solutions: In some cases, SOA has rebuilt the engine short block, while in others SOA prescribed "countermeasure pistons" with longer skirts that do not slap. Most dealers will initially state the sound is "normal."
Detrimental effects: SOA has said that the noise causes no engine problems or abnormal engine wear; Subaru engine expert CCR Engines of Colorado has said that the engine may experience a 10% reduction in life.


if this is prominent in 97-1999 engines why am i hearing it in a 06 ? are they still using the short skirt pistons ? also i have low millage. i have 55k on my car. Im not trying to start an internet battle of knowledge i am just trying to understand this myself.

thanks.
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Old 12-30-2012, 05:36 PM   #17
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Old 12-31-2012, 02:31 PM   #18
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^^ good videos. i subscribed to his channel.
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Old 01-02-2013, 12:44 AM   #19
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I have had piston slap in my 96 ej22 phase 1 in just cylinder 4 since 121k miles and the car has 203k miles on it right now. The piston slap actually gets a touch louder once the engine in my car warms up but goes sway once I rev it past 1500 rpms.... In fact, I have seen the bits of material in the oil at times though, but almost can't see it. It's not like a lot but just a few tiny bits though.

Uncle Scotty this is for you... I was using quaker state 5w30 in my 2.2 from 121k miles up to around 178k then I switched to the T-6 5w40 and after 3 or 4 oil changes really only made it smoother after start up and when idling. It DID NOT make the piston slap go away... So oil isn't the one thing that can make a difference...Sometimes a light re-hone and re-ring is in order...
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Old 01-02-2013, 02:39 AM   #20
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Incorrect sir. If that were the case, piston slap would be a symptom of warm weather where the oil would be less dense upon startup.

...

cupcake.....this was happenin in florida....we aint got a whole lotta winter there

think 50's and 60's.....that is cold weather in florida


so no....piston slap can happen not in winter

and 'density' has NOTHING to do with it and you dont know crap about oil....just like the very vast majority of those out there who THINK they do
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