Engine Noise
- Thread starter 3oilmat1
- Start date
- Status
I have been answering this question all night: please read Dr. Haas's very nice lecture that explains why this happens
linky; read and learn, I did
http://ferrarichat.com/forum/faq.php?s=2...otor_oil_basics
linky; read and learn, I did
http://ferrarichat.com/forum/faq.php?s=2...otor_oil_basics
Originally Posted By: c3po
Good question, which oil's have you heard quiet an engine.
I don't recall off the top of my head. I run Valvoline Syn in my Subaru Tribeca but it seems like it idles a little loud (nothing major). Could be just me reflecting on all the posts that I read here. I run 5 W30 with a factory filter. Next oil change I'm using the same oil with a Wix filter.
Good question, which oil's have you heard quiet an engine.
I don't recall off the top of my head. I run Valvoline Syn in my Subaru Tribeca but it seems like it idles a little loud (nothing major). Could be just me reflecting on all the posts that I read here. I run 5 W30 with a factory filter. Next oil change I'm using the same oil with a Wix filter.
I've never noticed a difference in noise among the brands I've used.
Wow what a great article! Thanks
SSO and RP, I noticed the engine is alot quiter over Mobile 1 and GC. How about PP
Maybe because the consistency/sameness of the molecules of certain oils transmit sound more efficiently .
Well...keep in mind that Dr. Haas, MD, is a cosmetic plastic surgeon, not an automotive engineer, organic chemist, or tribologist. Some of what he writes is well known and widely distributed, some is inaccurate, some is just sloppy writing like his writing about oil "thickness" and designed oil temperature, and some ignores clear, long-known lubrication principles like the hydrodynamic wedge of oil that lifts the rotating journal off the bearing.
Oil thickness is the oil film thickness measured in thousandths of an inch. Oil viscosity is something else. He's confusing thickness with viscosity. Oil temperature is not controlled in most automotive engines...many have no oil cooler nor any type of thermostat to regulate oil temperature. Most oil systems are cooled by air passing by the oil pan and unregulated heat transfer through the block & heads into the coolant.
Back to the original question...some brands of oil tend to damp noises. We don't know exactly which characteristics cause this.
Oil thickness is the oil film thickness measured in thousandths of an inch. Oil viscosity is something else. He's confusing thickness with viscosity. Oil temperature is not controlled in most automotive engines...many have no oil cooler nor any type of thermostat to regulate oil temperature. Most oil systems are cooled by air passing by the oil pan and unregulated heat transfer through the block & heads into the coolant.
Back to the original question...some brands of oil tend to damp noises. We don't know exactly which characteristics cause this.
Originally Posted By: Ken2
Well...keep in mind that Dr. Haas, MD, is a cosmetic plastic surgeon, not an automotive engineer, organic chemist, or tribologist. Some of what he writes is well known and widely distributed, some is inaccurate, some is just sloppy writing like his writing about oil "thickness" and designed oil temperature, and some ignores clear, long-known lubrication principles like the hydrodynamic wedge of oil that lifts the rotating journal off the bearing.
I was feeling masochistic so I decided to reread some of his writings.
In his chapter 1 I ran across this jewel...
Quote:
There is a one to one relationship between flow and separation. If you double the flow you will double the separation pressure in a bearing.
I could go no further.
Well...keep in mind that Dr. Haas, MD, is a cosmetic plastic surgeon, not an automotive engineer, organic chemist, or tribologist. Some of what he writes is well known and widely distributed, some is inaccurate, some is just sloppy writing like his writing about oil "thickness" and designed oil temperature, and some ignores clear, long-known lubrication principles like the hydrodynamic wedge of oil that lifts the rotating journal off the bearing.
I was feeling masochistic so I decided to reread some of his writings.
In his chapter 1 I ran across this jewel...
Quote:
There is a one to one relationship between flow and separation. If you double the flow you will double the separation pressure in a bearing.
I could go no further.
- Joined
- Dec 30, 2006
- Messages
- 29,558
Originally Posted By: NHSilverado
Originally Posted By: c3po
Good question, which oil's have you heard quiet an engine.
Royal Purple
Quaker State Horsepower
^^I agree with Silverado. Royal Purple all the way.
Originally Posted By: c3po
Good question, which oil's have you heard quiet an engine.
Royal Purple
Quaker State Horsepower
^^I agree with Silverado. Royal Purple all the way.
Last edited:
When I change brands (which is not a rare occurance) new oils always tend to sound louder for the first 500-1000 kms. If it is already quieter at the begininig it further quietens. If this is the new "surface chemistry" that needs to phase in than it has a audibly observable effects. It went continiously more siilent with the Elf till the change at 7500 miles.
My older v6 GMs all orchestral performance seem to be consist of valvetrain noise and the silence. Likes thinner, synthetic oils best. For surface tribology among brand names (don't know what this should mean) Mobil sounds best, followed by Elf, Belgian Havoline or Shell (SOPUS). Castrol is loud. Cross comparison of brand /weight /basestock goes like: Castrol Formula SLX 0w 30 is quieter than regular Mobil 5w30 and Elf Excellium 5w 30 when cold, louder than Elf for hot. Mobil 15w 40 is quieter than Castrol's 5w 30 Magnatec. 15w 40 Castrol GTX made the most noise.
Delvac's 15w 40 -given the thickness- gave this car a surprising lucidity. I tend to think what was on GM's head while designing these engines' tribology was a model like the Mobil's -at least once upon a time.
Next I should try SuperSyn 0w 30 or 0w 20 as these half decent analytics dictate.
My older v6 GMs all orchestral performance seem to be consist of valvetrain noise and the silence. Likes thinner, synthetic oils best. For surface tribology among brand names (don't know what this should mean) Mobil sounds best, followed by Elf, Belgian Havoline or Shell (SOPUS). Castrol is loud. Cross comparison of brand /weight /basestock goes like: Castrol Formula SLX 0w 30 is quieter than regular Mobil 5w30 and Elf Excellium 5w 30 when cold, louder than Elf for hot. Mobil 15w 40 is quieter than Castrol's 5w 30 Magnatec. 15w 40 Castrol GTX made the most noise.
Delvac's 15w 40 -given the thickness- gave this car a surprising lucidity. I tend to think what was on GM's head while designing these engines' tribology was a model like the Mobil's -at least once upon a time.
Next I should try SuperSyn 0w 30 or 0w 20 as these half decent analytics dictate.
Originally Posted By: webfors
Castrol GTX quieted all engines I've run in it. Is it the best oil for all applications? I don't think so. But it's smooth as butter
I don't run conventional oil much anymore but when I do I use GTX. It was pretty much all I ran before becoming a synthetic convert. However, in my current engine( 2008 GM 3.4L V6 )when I swapped out the FF at 900 miles for the very 1st OC I found that the 5W-30 GTX seemed to make the engine noticeably louder and even a bit rougher running( I know I know it is all in my head - but it IS what happened ). Was really surprised as I have never experienced that before with it.
At 5k when I did the swap over to RP 5W-30 it really quieted it down and smoothed it out. Just night and day difference and what I have experienced every time I have swapped an engine over to RP( all my Dodge and GM truck engines have loved RP ). When I swapped over from RP to QS HP( long story - API level related )it is still smooth and quiet although it does not appear to be quiet as smooth and quiet as with the RP. Definitely much better than the FF or the GTX however. I have always had good luck with QS blends and full synthetics quieting down and smoothing out engines.
The GTX at least in this engine was really a disappointment.
Castrol GTX quieted all engines I've run in it. Is it the best oil for all applications? I don't think so. But it's smooth as butter
I don't run conventional oil much anymore but when I do I use GTX. It was pretty much all I ran before becoming a synthetic convert. However, in my current engine( 2008 GM 3.4L V6 )when I swapped out the FF at 900 miles for the very 1st OC I found that the 5W-30 GTX seemed to make the engine noticeably louder and even a bit rougher running( I know I know it is all in my head - but it IS what happened ). Was really surprised as I have never experienced that before with it.
At 5k when I did the swap over to RP 5W-30 it really quieted it down and smoothed it out. Just night and day difference and what I have experienced every time I have swapped an engine over to RP( all my Dodge and GM truck engines have loved RP ). When I swapped over from RP to QS HP( long story - API level related )it is still smooth and quiet although it does not appear to be quiet as smooth and quiet as with the RP. Definitely much better than the FF or the GTX however. I have always had good luck with QS blends and full synthetics quieting down and smoothing out engines.
The GTX at least in this engine was really a disappointment.
Last edited by a moderator:
My '00 MB E430 with 100k miles had M1 0W40 all its life was much quieter when I tried PP 5W20 8 months ago. I don't think PP quiets the engine noise down but W20 is the reason.
The car has Delo 15W40 now and the engine noise is back to previous M1 0W40 level. Next oil change I'll use either Synpower 5W20 I bought on sale for $0.49/qt 3 months ago or M1 0W20 I bought last year on clearance from WM for $2/qt
I think MB E430 requires ACEA A3/B3 oil and it is a thick oil (HTHS of 3.5), thinner oil reduces engine noise substantial. I may end up with a compromise oil of a thin 0W30 (not thick GC 0W30)
The car has Delo 15W40 now and the engine noise is back to previous M1 0W40 level. Next oil change I'll use either Synpower 5W20 I bought on sale for $0.49/qt 3 months ago or M1 0W20 I bought last year on clearance from WM for $2/qt
I think MB E430 requires ACEA A3/B3 oil and it is a thick oil (HTHS of 3.5), thinner oil reduces engine noise substantial. I may end up with a compromise oil of a thin 0W30 (not thick GC 0W30)
- Status
