What are the ways to reduce car's engine noise and changing the engine sound besides adding insulation?

use friction reducer products like torco mpz or liqui moly ceratec.

most of the noise from the engine is due to friction....by adding products above, it bonds to the metal and acts like a slippery lubricant.

pros - engine becomes smoother, less engine sound and longer engine line
cosn - engine braking is not as effective as before and a bottle can cost between 100-150

No other way. Only insulation. And no sports exhaust.

I oso very interested.
Insulation can only do so much to a practical extend.

So far i added some weights to the engine cover to reduce the vibration and cover the firewall with heavy rubber mats.

Its the internal vibration , using good engine oil reduces friction and vibration . Mass produced engine high high tolerance unlike sports/supercar with very very low tolerance in their engine fittings

I don't really buy into such products as many of them are just snake oil stuff and even detrimental to the engine as they can become oil sludge! Just buy good trusted oil brands with the proper recommended characteristics and viscosity and it would fine.

replace engine mounting
use xW50 lub oil and above. But Your car will feel heavy.
use smaller exhaust diameter piping and smaller exhaust and retain the catcon.

Apart from insulating the noise, you can also use engine oils that can helps the engine run smoother, do some research on various engine oils and you should come across some. Usually if originally it is already noisy due to poor insulation from the factory, you'll just have to learn to live with it. Adding aftermarket insulation will help but you can't expect the engine noise to be on par with luxury cars.

oredi using total quartz 10w50 fully syn wor . . .

Then u cant really do much to the engine sound anymore . The only way is to insulate the whole car firewall and adding rubber to prevent wind noise from coming in. By this u will get better driving pleasure

Can anyone tell me exactly how engine oil reduces VIBRATION? Not noise?

both torco/liqui moly are very reputable companies and have their products certified/tested under many standards which includes but not limited to the American petroleum institute

http://www.shell.com.au/products-services/...diesel-hx5.html

how exactly? perhaps less friction, better film strength reduces/prevents engine parts knocking against each other and such force is then transferred towards your engine > engine mounting which are supposed to absorb them and if they are worn/bad condition then it gets transferred to you

Thats diesel engine. Where the internal combustion is more violent than petrol counterparts. High compression engine. So noise and vibration is expected. Worn or badly designed engine mounts can be the cause of vibration transferred to car body. But engine oil? There is another thing that will definitely reduce engine vibration. But it cost a lot of money and time. Drive train vibration is another story.

This post has been edited by netmatrix: Dec 9 2013, 09:50 AM

http://www.shell.com.au/products-services/...ltra/ultra.html
nah petrol.

Rebuilt the engine if the engine is already old?

use higher ron petrol, it gives your car the required combustion timing = less rough and less vibration to your car engine = reduction of sound..

by insulating your car does the trick...sport exhaust? that one is exhaust noise...not engine lor

Use better engine oil is bollocks. Really. The best method engine balancing. Last time got a 4AGE 20v with balance rod and pistons, the engine ran on 3 cylinder but cannot feel the harsh vibration not is it that obvious visually. But lost of power. Hows that for engine vibration reduction? If balance crank i think totally does not know the engine cyclinder no combustion. 6 cylinder inline engine even better at masking vibration.

I meant additional additives that are marketed to add into whatever your existing engine oil. I rather buy good oil only without adding any more additives on it. I don't trust mixing chemicals from one brand to another one as I won't know if it will go bad until it's too late already. If one prefer Torco or Liqui Moly, then just buy the engine oil and that should be good enough already, don't use say a Castrol then add more additives even from Torco or Liqui Moly, or whatever. If still want to use such additional additives, better use from the same brand. Btw I also heard of not so good review about Torco though.