Author Topic: Engine Noise - normal or not (Read 3249 times)

sumyungguy · « **on:** April 05, 2007, 10:47:44 PM »

I really don't like to post these kind of questions because its impossible to diagnose a car without seeing and hearing it.

I had the super raspy old stock exhaust replaced with a "muffler shop" setup, new muffler, piping, and put in a resonator (previous owner replaced the stock one with a piece of pipe). So now I can actually hear the motor, and under load theres a hissing sound from the passenger side towards the front.

My first thought was exhaust leak, put it up on the lift and theres no visible spots between the flange after the cat up to the collector on the header.

Are these motors just kinda hissy when running? I don't have any other m42's around me to compare to. There’s a lot of mechanical noise, the motor isnt quiet, but nothing that sounds major to me. My last three B-series (dual over head cam vtec) Honda motors where kind of loud cause they had cams and stuff, so I'm youst to it.

So in conclusion..
Is the m42 generally a quiet motor (mechanically)?
Is the hissing sound (similar to small exhaust leak) under load a norm?

motor is at 161k

Thanks.
-Brad

rhogg · « **Reply #1 on:** April 06, 2007, 01:16:23 AM »

Chain tensioner ? Does the hiss start around 2800 RPM? My tensioner should arrive next week. I'm hoping it will eliminate a similar noise.

sumyungguy · « **Reply #2 on:** April 06, 2007, 01:28:02 AM »

I'll drive it tomorrow and see if theres any specific areas it does it, but it think it all of the time. I thought there where concerns with putting a new tensioner on a old chain? If that where the case Id replace everything chain related.

Alpine003 · « **Reply #3 on:** April 06, 2007, 11:48:18 AM »

You sure the hissing isn't the intake?

arthurc · « **Reply #4 on:** April 06, 2007, 12:37:33 PM »

Funny - I was just wondering exactly the same thing the past few days. Intake makes sense, except it does seem to come from around the firewall and I can only hear it with the windows up.

I replaced my chain tensioner a year ago (the old one was the orginal design completely seized not doing much tensioning at all) and it reduce the clacking noise by quite a bit.

I did read the accounts on a forum (can't remember where) about broken guides/sprockets. The theory was that running the engine with no tensioner, before revving up to release the new tensioner, caused a large amount of damage. I did the install by the book and I haven't had any problems (yet), but the suggestion was to install the tensioner in its released state instead of compressed state. It won't be easy, but could be worth a try.

Choking Hazard · « **Reply #5 on:** April 06, 2007, 12:42:02 PM »

What viscosity oil are you running? My timing chain has a loud and distinctive hiss when the oil is too thick. I was really surprised what a difference it made.

sumyungguy · « **Reply #6 on:** April 06, 2007, 02:19:26 PM »

Quote from: Alpine003;23090

You sure the hissing isn't the intake?

I can hear that on the drivers side, this is very much on the passenger side..

Quote from: arthurc;23091

Funny - I was just wondering exactly the same thing the past few days. Intake makes sense, except it does seem to come from around the firewall and I can only hear it with the windows up.

I replaced my chain tensioner a year ago (the old one was the orginal design completely seized not doing much tensioning at all) and it reduce the clacking noise by quite a bit.

I did read the accounts on a forum (can't remember where) about broken guides/sprockets. The theory was that running the engine with no tensioner, before revving up to release the new tensioner, caused a large amount of damage. I did the install by the book and I haven't had any problems (yet), but the suggestion was to install the tensioner in its released state instead of compressed state. It won't be easy, but could be worth a try.

Maybe Ill look into this, that will probably get rid of some mechanical noise..

Quote from: Choking Hazard;23093

What viscosity oil are you running? My timing chain has a loud and distinctive hiss when the oil is too thick. I was really surprised what a difference it made.

I havent changed it yet caue the previous owner had just chaged it 50 miles before I bought it Im gonna change it when I get 2500 miles on it.. What viscosity are you running?

Choking Hazard · « **Reply #7 on:** April 16, 2007, 03:22:45 PM »

10w30 mobil 1 synth is the oil I use When I used a 40 weight oil, I got the hiss sound.