Hi everyone,

I'm a typical DIY mechanice with a small garage, basic tools and of course limited car knowledge But I enjoy working on my car and always have a back-up car too while doing repairs.

I have an automatic transmission Honda Accord 1991 and it has a very loud engine noise while driving. I have recorded the sound with my phone and put it on utube. Here's the link:

MOV015 - YouTube

When the noise first started it would start for 4 seconds and turn off for 3 seconds and cycle like that over and over, perfectly timed on and off. Now the noise stays on for longer periods of time with shorter "off" times. The noise will only activate while in driving (even in reverse).

Is it the AC system you think?

Thanks

 

any ideas? It's so hard to see where the sound is coming from since it only does it while in gear and moving. but recently the sound has started to go consistently since I was able to get the video of it but it eventually shuts off again and wont start again until driving.

 

Noises are tough to diagnose over the web.

If this only happens when in gear, when was the last time you changed the transmission fluid?

If the noise starts happening while driving, put the car into neutral and let us know if the noise remains.

 

Does that web link work to the utube video that has the noise sound on it? Sometimes the forums block these links?

It's definitely not the tranny. The engine power and performance is not compromised at all. There's no noise when the car is in neutral and revved up. There is no noise when the car is in drive and idling at a stop. Only when I hit the gas pedal the noise starts and will remain and will not stop until the car is not moving.

The noise cuts in and out and cycles on and off perfectly, ex: on for 4 seconds then cuts off for 1 second, then back o n for 4 seconds then off for 1 second, over and over again. Whether I'm revving up to gain speed or just coasting at 10 mph. the sound remains consistent.

 

I could watch the video.

How did you get this video of the noise, since the car has to be moving to hear it?

 

lol, I thought someone might ask that. It just started randomly making the noise without stopping for about 30-45 seconds and I was able to get that sound before it stopped after stopping the car.

 

What are somethings that "click" on and off in the engine? It sounds like the noise is "clicking" on and off. Compressor clutch? condenser?

 

Locate the a/c compressor. There should be one wire going to the compressor (red, I think). Unplug that electrical connector. See if the problem goes away.

I would do the same thing for the ABS modulator.

 

Has timing belt ever been replaced? This sounds like a loose or rattling idler on the timing belt. Suggest removing the upper timing belt cover to see if noise is coming from inside the timing belt cover.


You might try disabling the accessory belts sequentially to see if noise is coming from PS, Alt, or AC rotation. You can run like this for long enough to diagnose.


good luck

 

Thanks, I'll try this tomorrow.