Engine Oils and Noise

[Merkava_4]

I'm starting this thread rather than high jack Dr. Haas's thread. He said this in his thread:

Quote:

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Note that in any engine going to a thicker oil will in one way make it more quiet. The thicker oil on the inside surfaces will act as a better sound buffer. Going to a thinner oil can only make it more quiet by some other method. The Murcielago was delivered with OEM 5W40 Agip, the engine was very noisy. I changed to 0W30 Mobil 1 and it became more quiet. Then I changed to the 5W20 Red Line and the engine is almost silent, it is definitely soother as well.

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I don't doubt for one second that the Red Line 5W-20 made his Murcielago run quieter than the Agip 5W-40, but I just want to know why?


The old way of thinking is that thicker oils always offer quieter valvetrain operation; how can a Group IV synthetic that is on the thin side of kinematic viscosity make an engine run almost silent?


What if you had two engine oils that were of the SAME kinematic viscosity, yet one of them made an engine run much quieter than the other; how would that be possible?

 

[416Rigby]

Red Line oils do indeed make engines run quieter. I always figured it was the massive amounts of additives in their oils that are responsible for this. Every engine I tried Red Line oil in became completely silent after the change.

 

[Triple_Se7en]

I doubt it's the additives. Moly is overly abundant in Red Line - yet the old Havoline ran no quieter in my vehicles.

I would think it's the base oil.
For instance:

I've complained a few times in the past years about slightly louder engine with Mobil-1 SL. Well I'm hearing it again with Amsoil ASL 5W-30. It's noticeably louder than my previous Quaker State QTorque Power 5W-20 - which is thinner. I suspect Amsoil is using Mobil-Exxon base oil & that might explain it. Some of this noise might be a Group IV thing -- I dunno!

 

[aquariuscsm]

Quote:

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I suspect Amsoil is using Mobil-Exxon base oil & that might explain it. Some of this noise might be a Group IV thing -- I dunno!

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I Googled "base oil" awhile back and a thread came up (it might`ve been a Mustang forum as well as I can remember)that said Ams uses Mobil for their base oil and RP uses BP for their base oil........who knows if it`s rumor or fact seeing that you can never believe everything you read on the net. With engine noise,I get the opposite with M1. I can leave my car unstarted for 2 weeks (the longest it`s ever sat unstarted when I went on vacation) and I don`t even get the slightest hint of lifter tick or any weird noise on initial startup. Smoothest and quietest oil I`ve ever used.

 

[Triple_Se7en]

I wasn't discussing startup noise -- just overall louder-sounding engine thereafter. The engine sounds louder - with no specific ticks or clatter.

My Colorado 4X4 has a vertical filter mount with no ADBV in the filter - plus a large channel of oil that sits right above that filter. Result?.... always full of oil & no startup noise ever.

 

[PT1]

 

[4esorselrahc]

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[Merkava_4]

Thanks for all the replies guys; although I don't know what 4esorselrahc is trying to say.

I need to change my old way of thinking about thin oils and keep a more open mind I suppose; but it's just that I've read so many noise complaints about thin oils, that I don't know what to make of it.

 

[mechtech2]

Also, a new engine breaks in.
So getting quieter is no miracle, after 2 oil changes.
We will never know the results if one type of oil was used.

 

[AEHaas]

I have seen some engines become more noisy and others become less noisy after changing oil brands even though the same grade was used. If somebody asked me what to try for a noisy engine I would recommend using a different brand, not a thicker grade as most people would jump to.

aehaas

 

[aquariuscsm]

Quote:

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I wasn't discussing startup noise -- just overall louder-sounding engine thereafter. The engine sounds louder - with no specific ticks or clatter.

My Colorado 4X4 has a vertical filter mount with no ADBV in the filter - plus a large channel of oil that sits right above that filter. Result?.... always full of oil & no startup noise ever.

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Oops,sorry. Guess I need to read more carefully

On a noisier engine during running,I tried M1 5W30 a long time ago and my engine was definitely a bit noisier (maybe just in the valvetrain). To my horror I opened up the owners manual and it warns not to use 5W30 in the VG30DE.

 

[lovcom]

So is there a correlation between engine noise and wear?

 

[toocrazy2yoo]

Not necessarily..

My little roller-skate 1.6 Hyundai has run every brand there is in 50K, 0W30 GC, 5W20, 10W30, 5W30, Pennzoil dino and PP, Havoline, QS syn, Motorcraft, even a run of M1 (I like variety) and I've never heard so much as a tick in my engine. That'll be put to the test in a bit, I suppose, when I run an OCI of 0W20 M1 that someone gave me awhile back along with an M-104 Mobil1 filter. Noisy or no, it should hold together for a 3K OCI, right?

 

[Triple_Se7en]

Quote:

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I have seen some engines become more noisy and others become less noisy after changing oil brands even though the same grade was used. If somebody asked me what to try for a noisy engine I would recommend using a different brand, not a thicker grade as most people would jump to.

aehaas

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I may switch from Amsoil ASL to Amsoil XL next OCI. I usually only run 6K OCIs anyways.

 

[buster]

I've used numerous brands of oil and never really had noise issues with any brand. It's probably a number of things that an impact noise levels. Additives/viscosity/density/base oils etc. bruce said something about certain base oils (I think non-synthetic) wetting the metal better. The important thing is to monitor it and have a UOA done.

 

[PT1]

My piston designer friend claims that the 10w oils will cling on better and give you enough residual film to quiet or at least reduce piston slap or vt noise on cold starts. PP 10w30 seems to have viscosity numbers close to Mobil1 0w30 so it may be the answer to my cold start noise issue. I'll give it a try soon and report back my experience. One thing for sure....I'll have the cleanest engine on the forum.

 

[bluesubie]

I cannot get my wife's '99 Outback to quieten down regardless of what I use. The engine for that MY is known for noisy lifters when cold.

I've tried Havoline 5/10W30, GTX 5/10W30, GTX Start UP 10W30 and Vavoline 10W40. I've done two UOA's on it and they were both very good as far as wear.

Wanted to add some SLOB but now I can't find it.

-Dennis