Engine rattle?

I have a 2002 Corolla with a 1.8Liter 1zzfe engine.

I can hear a loud “rattle” at 1950 rpm from the drive belt area whether I’m driving down the street or if I rev it up while parked in neutral. It’s not a tapping sound, more like a sheet metal rattle but I can’t locate an loose sheet metal.

I thought it might have been the drivebelt tensioner. The plastic bushing on the small bolt cracked to pieces and I simply replaced it with a stack of washers. That’s the bolt at the top of the piston that screws into the valve cover. I replaced the tension but still hear that rattle. I tried to locate it with a stethoscope but no luck

Anyone have any ideas what this could be? Any help would be greatly appreciated.

Noises from a loose or bent heat shield on the exhaust system are pretty common nowadays, and that would be my prime suspect. There are heat shields on the exhaust manifold under the hood, and on the exhaust system underneath the car, and they are all made of–guess what?–sheet metal.

I suggest that you check all of the heat shields when the engine and exhaust are stone-cold, and–more than likely–you will find the culprit.

Depending on the miles on the engine, the noise might be from a stretched timing chain.



Take the belt off for a quick test at 1950 rpm. If the noise goes away, put on a new tensioner (and a new belt if it’s been a while).

Excellent advice above. I’d probably get out a length of garden hose and use it as a stethoscope to try to isolate exactly which area of the engine compartment the noise was coming from first. My first suspect would be the heat shield that covers the exhaust manifold in the engine compartment. Look carefully at that, if your engine has one, any missing or loose fasteners?

My corolla had the 1zzfe engine disappearing oil problem so two octobers ago at 139,000 miles I fixed that. Drilled 4 new holes in the third grove of each piston, changed the rings, bearings, timing chain, drive belt, a reman head, etc. but not the drivebelt tensioner. Car has been running well and only uses about half a quart in 4,000 miles which is much better than a quart disappearing every 700 miles. I say all of this in hopes that it might remind someone of a similar problem.

I’ll check the sheet metal mentioned above and if I don’t find a loose section or a missing or loose fastener I’ll try the garden hose idea.

Thanks guys!

I second removing the belt and turning all pulleys by hand, feeling for drag or uneven rotation. Try turning them while applying pressure to mimmick the belt tension.

VC DRIVER hit the nail on the head! I put the car up on jack stands and didn’t find anything. So I took the car to my tire guy who also has a tech school trained mechanic. He put it up on a hoist and when his helper set the RPM at 1950 the catalytic converter heat shield started rattling like beaucoup! Don’t know how I missed it except that I did my “feel around” and eyeball inspection was done when the engine cold and not running. Apparently the factory spot welds these replacement heat shields and one weld on the right side just gave way. I had him just twist the cussed thing off since there is a sturdier, heavier gauge shield just above it that is part of the floor pan. Total cost…$15.00…and well worth every penny! I wanted to pay for half an hour, $37.50, like we had agreed on but the shop manager refused. Anyway that’s one shop whose praises I will be singing.

Thanks to all of you!