Strange sound at 2000 RPM

[joe5118]

Hello Eric and

Topic

[619DioFan]

I checked out your vid , could here the sound somewhat. just have a few questions first… how many miles on the car ? do you have a check engine light on ?

If you have a cel on I would pull the codes . next , With the car in neutral , p-brake on and wheels blocked have someone bring the rpms up and watch the belt area. look for anything that might be loose or warped ( lower crank pulley , ps pulley etc ) if you have a mechanics stethascope you can listen around the moving parts. how old is the water pump ? perhaps a water pump bearing going out. if you can’t replicate the noise with the car at a stand still then I would start looking at things such as a wheel bearing going bad or perhaps tire noise ( switch the tires around and see if the noise moves to a different area ) hope this info helps. keep us updated on your findings.

[Grayfox]

When my mum got a new ford focus it made a buzzing sound at 2000rpm or so.

Turned out to be a Air Conditioner hose according to what the mechanic said.

[Third Gear]

The stethoscope is great idea. I’ve seen alternators with bad bearings make a similar sound around the same RPM. The sound has to be something connected to the engine that spins.

[joe5118]

Hi all, thank you for the input. As an update, I swapped the driver front and passenger rear wheels, I also bled the clutch system and got some pretty nasty looking fluid coming out, I had failed to mention some clutch pedal issues in my first posting. It doesn’t come back quite all the way when you let it out. I did notice the crank pulley has been chipped on the edge that holds the belt in place.

Also, the sound does not occur in neutral or when the load is off the car. The car has approx. 135k miles. There was a cel on, but it was for the catalytic converter. I had to clean the battery terminals and it has been off since then.

[dreamer2355]

Hello and welcome to the forums!

Check out this video made by Eric on finding suspension noises –

http://www.youtube.com/user/EricTheCarG … cFbb43fwqk

Did you ever examine the exhaust to make sure no hangers are damaged?

[joe5118]

Thank you dreamer. I actually watched that video intently and tried a few techniques but haven’t had success. The only time I can get any sound is while driving. I am about to go for a ride and see if I can capture it better, doesn’t seem to come through well from my cell phone video.

Thanks again!

[cb7ftw]

If you haven’t already, check you engine mounts.
Most likely the belt on that chipped crank pulley.

[joe5118]

Thanks CB7. I think I am going to be replacing the pulley this weekend. There is a constant whine (not a typical belt screech) that seems to be coming from a belt, so that may fix two problems, fingers crossed!

So I captured a better video (http://youtu.be/920IsgyB8IA) and you can definitely hear a better sample of what is going on. Through the process i noted a couple of things that I can add. Once the sound starts, it will stop immediately if I let off the accelerator or press in the clutch. Likewise, as soon as I begin to accelerate again the sound starts again.

Thanks to all!

[dreamer2355]

How you tried to ‘brake torque’ the engine to see if the noise is present then?

It sounds like a engine or trans mount.

How is the clutch operating?

[joe5118]

The clutch as of this morning is operating terribly, hard to select gears. A bleed didn’t assist, so I may need to replace one or both cylinders. I get a creak sound at the slave. cylinder area when depressing the pedal. I need to check the mounts, haven’t done that yet.

[dreamer2355]

Does the clutch pedal stay low after you have depressed it? That’s usually an indication of air in the system if its hydraulic as well as a potential hydraulic leak.

http://www.youtube.com/user/EricTheCarG … 7JJ_g2UuBI

Above is a link to a video Eric produced on clutch diagnostics that may help you.

[EricTheCarGuy]

Interesting noise. I think the first step is to figure out if it’s coming from the engine or the drive line somewhere. Since it occurs at a given RPM and not a given speed I would suspect that it’s coming from the engine but to be honest I’m not sure. I would check the engine mounts as suggested as with a manual car they tend to wear a lot more, it may be that it’s making the noise all the time but is only audible during that ‘sweet spot’ in the rpm range. You might try rocking the car forward and back while it’s in gear (parking brake off) as you watch the engine and listen to the mounts, once you get it moving if the engine has loose or broken mounts you should be able to see and hear them more clearly. Keep us posted.

[Author]

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