'97 Camry rattles inside timing cover

Len wrote:
> Hard to run with covers off, because I
> have to remove motor mounts and belts to get inside cover.
==
You can run the engine with the timing cover off.
Accessory belts only run alternator and power steering - for a short
time, car stationary, you can run without those.
Engine moving control rod is primarily for holding the engine under
load, again you can run without that at low speed, no load.

"Len" <1@2.com> wrote in message
news:enuvu2lt0vko5m6narn9kdikog9q3a8239@...
> My '97 camry rattles inside the timing cover only when the car is
> cold. Sounds like bearing failure. I replaced the Water pump and
> both idlers when I did the timing belt even though they all felt fine.
> The noise went away for about 5K miles and returned. It only happens
> cold, and only at low idle. Hard to run with covers off, because I
> have to remove motor mounts and belts to get inside cover. Any
> Ideas??
> Len

Be careful here that you dont do unecessary work. If you replaced both
idlers, its not likely they have started to go noisy by now or that they
would get quieter as the engine heats up,..same goes for the w/pump. Noisy
pumps stay noisy all the time. so do ball- bearings for the most part. What
you may be hearing, and this is an opinion only, could be cam-drive
gear-chatter or the engine pulley (harmonic balancer) centre-bolt may have
loosened. The pulley would be easy to check,..the cam-gears, I'd leave alone
unless the noise got worse.
Try to narrow the area where the noise is coming from, by using a
stethoscope. Check all the stuff up the front, including bolt-on gear such
as alternator, PS pump, AC comp etc.

Jason

"Len" <1@2.com> wrote in message
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>
> The last time I looked at this problem some months back the
> stethoscope indicated the noise right behind the upper timing cover. I
> may have to bite the bullet and run with the cover off to find out for
> sure. Timing belt has about 40K on it which is young but I might
> replace it at the same time. In another forum someone said they had a
> bad noise that went away when the belt was replaced. It doesn't make
> sense but otherwise I'm stumped. Thanks Daniel and Jason for the
> suggestions.
> Len

Running it without the cover is a good idea. A friend had a similar noise
which had everyone beat, That eventualy turned out to be a loose
crank-pulley which had been loose for so long it was rattling against its
shaft-key. I forgot to mention the belt-drive pulley on the the exhaust cam
(the top pulley). You should be able to test the cam and crank pulleys for
looseness by hand (engine off of course).

The belt itself wouldnt be making such a noise, but the tensioner pulley
which keeps the belt tight maybe. If I had to scale the liklehood of which
item is causing this rattle, it would be: drive pulleys (crank and cam),
tensioner pulley, then water-pump, loose idler pulley, cam endfloat, cam
drive-gears noise.

best o luck,...Jason

"Len" <1@2.com> wrote in message
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>
> Well, I didn't need the stethoscope once I got the cover off. I can
> see the loose belt chattering in time with the noise. Tighten the
> belt - noise gone! Amazing. Iwould never have believed it wasn't a
> bearing. The noise appears to be from the belt tooth catching the
> edge of the pulley tooth and snapping into place. The belt is so
> loose the spring on the idler isn't enough to retension it.
> Aftermarket ! Next belt from Toyota. Thanks all for the help.

Glad you found the problem. I wouldnt have picked a loose drive belt,...but
you live and learn.

Jason

Is engine 4 cyl or v 6 ?