Quiet engine and the Placebo Effect.

[Koz1]

Originally Posted By: wemay
Originally Posted By: ARCOgraphite
IN my Nissan rogue
Cheap fake grpiii syn = LOUD and wearing, Magnetec SS = pretty darn quiet.



Does 'loud' necessarily mean more wear?


Good question.

 

[Shannow]

Originally Posted By: Koz1
Originally Posted By: wemay
Originally Posted By: ARCOgraphite
IN my Nissan rogue
Cheap fake grpiii syn = LOUD and wearing, Magnetec SS = pretty darn quiet.



Does 'loud' necessarily mean more wear?


Good question.


Don't worry, it's a rabbit hole that I'm exploring at the moment.

e.g.
http://link.springer.com/article/10.1007%2Fs00170-005-0280-x#page-1

Note it's not saying that noise causes wear but that acoustics can be used to track ring wear.

 

[dew]

I switched from "dino" 5w30 in my 5vz-fe at about 50k miles to M1 5w30 to facilitate my 10k OCI post-warranty.

When I switched, I had no expectation of a change in noise whatsoever, I just expected it to protect well enough for 10k. I had never heard that M1 or synthetics in general could tent to run noisier.

One of the first things I noticed after the swith was an increase in what sounded like valve train noise, mostly at idle.

For whatever reason I stayed the course with M1 5w30 and my perception of increased noise and am now at over 270k. I finally bit the bullet and had the dealer check valve clearances at ~260k (first check). They were all still perfectly in spec.

Do I think the M1 ran noisier than the Chevron Supreme I ran before it? Absoutely. Do I think that noise was associated with wear? Nope. Not in any meaningful way.

Of course this is anicdotal but I have enough miles on extended drains to convince me that the added noise amounts to a minor annoyance.

I'm aware of the power of suggestion, and agree with others here that the placebo (or nocebo) effect is not the correct term since no healing is involved here.

 

[BobFout]

Does anyone know what percentage of a running engine's total sound is from combustion vs. moving parts? (some oils buffer combustion sound more than others)

 

[dew]

No idea of the percentage but I expect that the tonal quality of the moving parts is different. That's why a simple dB measurement between oils may be useless, as the human ear/brain is very good at perceiving differences in tone/pitch.

 

[Shannow]

http://eprints.hud.ac.uk/21925/1/1_ICSV21_Full_paper_nasha_wei_201409-hud.pdf

 

[fdcg27]

I've never changed the oil in any car and not noticed that the engine sounded smoother and quieter after the change and I'm old enough these days that I have no need to kid myself.
Wear?
Well, there is plenty of documented research to show that wear is probably higher in the first few hundred miles on fresh oil.

 

[dew]

Me too, it's always VERY quiet for the first few hundred miles or so after a change. My truck also gets quiet when it's very hot outside, maybe 105F and above.

 

[Crashbox]

My '95 Civic is always quieter immediately after an oil change; it returns to normal clackityclackiness after about three weeks or so..

 

[Kuato]

Originally Posted By: 440Magnum
Everyone seems to be ignoring the most interesting things in that table:

1) "right after" an oil change is frequently louder than a week after an oil change.

2) Of the cases where the change to a 'shear stable 10w40' made absolutely no difference, one of them had SAE 20 oil prior to the change.

My conclusion: there's not nearly enough evidence in that table to show a definitive correlation with anything.





Agreed, which is why we need a couple of UOAs from the same engine, one with loud and one with quiet oil!

 

[virginoil]

The V6 3800 engine (Buick US equivalent) in my Commodore after the engine rebuild had a low sound / noise that similar to the sound that comes from the OLD manual Singer sewing machines could be heard whilst using Penrite 5W-40 semisyn and Penrite 5W-40 full syn oils, when the engine was idling.

After a couple of weeks of using Shell Helix HX8 5w-30 full syn my mechanic was still pizzed off with me, as I had made him change his favourite brand and a lower grade to the HX8 so, I had him listen to engine when idling.

He was baffled and gob smacked as the low that noise that came from the engine was gone and it has NOT returned after 18 months years whilst using the HX8. I have NOT gone back to Penrite 5W-40 to experiment.

I am satisfied it was the Shell Helix HX8 5w-30 quieted the engine.

 

[tig1]

I change every 10K and have never noticed any difference after a change.

 

[dew]

I maintain my parent's fleet and they have a Fusion also that I put M1 0w-20 in. There doesn't seem to be any difference after a change for them either. You can't really hear the valve train much from inside their car though.

Also, all of the vehicles I've maintained with hydrolic lifters never mattered either.

 

[caprice_2nv]

My 76 Oldsmobile 350 Rocket stays normal right after an oil change, but for years now I always notice a day or 2 following the oil change I can hear very discreet rocker arm clatter. Then it gets quieter again maybe a week later and stays that way until shortly after the next oil change.

I've also tried several different oils and for some reason it seems to stay quietest on 5w30 (tried Pennzoil platinum and most recently bulk conventional Pennzoil as I was broke). First time with conventional in years. 10w40 and thicker seem to create more valve train noise despite the fact that the engine is getting tired. it uses barely any oil but has about 6 psi oil pressure at idle and slightly uneven compression (for the past 80k miles at least). Probably 2-300k on engine.

It could be placebo but it's the opposite of what I would expect placebo to make me perceive.

My 200k mile 305 Chevy doesn't care what grade is in it, no change in sound. There doesn't seem to be any wear on this engine besides needing new valve seals again soon.

 

[Pagophilus]

Originally Posted By: virginoil

I am satisfied it was the Shell Helix HX8 5w-30 quieted the engine.


I am convinced that after every oil change the engine is quieter, and becomes progressively quieter again over the next 2 weeks or so (does it clean extra [censored] off the engine?). However, the human ear is not sensitive enough to detect what happens between that time and the next oil change, some 6-12 months down the track, unless there is a particular noise that commences. Likely the noise level goes back up again.

Does more noise mean more wear? I don't know, but I'd like to believe it does. Seems logical.

 

[virginoil]

Originally Posted By: Pagophilus
Originally Posted By: virginoil

I am satisfied it was the Shell Helix HX8 5w-30 quieted the engine.


I am convinced that after every oil change the engine is quieter, and becomes progressively quieter again over the next 2 weeks or so (does it clean extra [censored] off the engine?). However, the human ear is not sensitive enough to detect what happens between that time and the next oil change, some 6-12 months down the track, unless there is a particular noise that commences. Likely the noise level goes back up again.

Does more noise mean more wear? I don't know, but I'd like to believe it does. Seems logical.


In my case the low sewing machine noise was there for over 12 months after the rebuild using the Penrite oils and after I switched to Shell HX8 it disappeared after 2 weeks and has not returned.

This had nothing to do with the hearing ability of the ear AS the noise was quite clear and audible coming from the engine with the Penrite oils.

Plenty of cases on this site where valve-train noises either increase or decrease pending the oil used.

An ear with normal hearing is efficient in distinguishing noises.

 

[440Magnum]

Originally Posted By: Kuato
Originally Posted By: 440Magnum
Everyone seems to be ignoring the most interesting things in that table:

1) "right after" an oil change is frequently louder than a week after an oil change.

2) Of the cases where the change to a 'shear stable 10w40' made absolutely no difference, one of them had SAE 20 oil prior to the change.

My conclusion: there's not nearly enough evidence in that table to show a definitive correlation with anything.





Agreed, which is why we need a couple of UOAs from the same engine, one with loud and one with quiet oil!


And it better be backed with calibrated spectrograms showing not only the peak frequencies in dB, but how the frequencies shift around (if they do). The human ear SUCKS as an analytical tool. Its great as a general, "hey, something's different" detector, but that's all it can do well. Even people with "perfect pitch" don't have any amplitude calibration.