Catalytic Converter?

[negativecreep934]

I am having a few problems with my 1991 honda accord lx (auto) which I was thinking may be related to one problem. I will number them that way each problem can be addressed individually.

1. When I accelerate the car in first and second gear, I hear a whining noise. I originally was told by a mechanic that it was a timing belt glazing and had the timing belt replaced but this did not fix the sound. It only occurs during the first and second gear.

2. When I put my car in reverse it vibrates a lot more than I would expect it to. The car vibrates a little while in drive at idle but no where near as rough as while in reverse. The Rpms usually stay around 700 while in reverse and drive at idle.

3. A clicking sound is heard from my car after it warms up while driving and when the car is turned off while cooling. The clicking sound seems to originate from underneath of the car leading me to believe it has something to do with the exhaust system.

I have been reading up on some fixes to these problems and one that sticks out to me is a clogged catalytic converter. I was thinking if the cat was clogged it would impede the air flow causing a whining noise under the the initial acceration. This may also account for the vibration where the exhaust is getting backed up causing the engine to work harder. Finally I thought that if the cat was clogged it might cause it to heat up and clicking while it cools down.

I am not a mechanic so my ideas are just from me pieceing things together logically. If you have any idea of what is wrong please give me some idea of how much it might cost to get fixed.

Thanks for your patience and your thoughtful input.

[AccordCodger]

1. No idea, but a "glazed timing belt" is an absurd diagnosis. (Even a "glazed belt" wouldn't whine - it'd squeal - MUCH louder than a whine)
2. Probably motor mounts .
3. Normal - cooling of (mostly) exhaust components.

[jeffcoslacker]

The only sounds I've ever heard a convertor make were rattle, from broken grids (rare) or if REALLY stopped up, hissing, as the exhaust flow burns it's way through the shell.

I had the same thought as Codger, a motor mount or roll restrictor problem might be allowing contact somewhere under certain torque conditions.

You could try holding it back with brakes while you rev the motor in gear, and leave the hood up so you can watch what the motor does. Some amount of movement is normal, but if you notice that it lurches a large amount when you gas it, you've got a bad mount. You might be able to duplicate the noise when you do this, and with a helper, you might be able to pinpoint the source of the sound.

Sometimes a bad mount can press exhaust parts against the body, allow pulleys to touch parts they shouldn't contact, etc., and make some strange sounds/vibrations.

Ticking while cooling is normal, and Hondas have a lot of heat shields on exhaust parts, and those are the noisiest tickers. Shields are also notorious for wierd sounds too, whining isn't one of them, but odd buzzes and shrieks and zing type noises are common. Usually occur at one certain rpm range when accelerating. You might wanna look into that as a possibility too.

Glazed timing belt? No. Noisy tension/idler? I could buy that.

Anyway, I suspect your cat is fine. You would notice serious performance/mileage issues with a restriction in there long before you'd hear anything. I bet you'll find it if you check it like I described.