rattling noise from engine

[drtyd1]

Can anyone out there help me figure out why there is a rattling noise coming from engine when accelerating around 2000RPM? The rattle goes away slightly when I let off the gas but can still be heard a little bit.

The car is a 2003 aerio and has about 76k miles. Just bought it and don't know if this is something really serious or not.

[hriehl1]

I had rattles that were from the exhaust system... some sort of baffles that came loose. Is it possible the noise is coming from under the car and not from the engine compartment?

[lumpylarry]

if not maintained well, the timing chains can start making alot of noise, if they break, it will get very expensive. try to pull the valve cover off and look to see how much sludge is in there.

[drtyd1]

Originally Posted by hriehl1

I had rattles that were from the exhaust system... some sort of baffles that came loose. Is it possible the noise is coming from under the car and not from the engine compartment?

--------------------------------------------------------------------------------

Thanks, I appreciate it! I let a mechanic look at it and thats exactly what he said too. I don't know how easy it is to fix, but he thinks I should take it to a exhaust shop. What did you do?

[Jeff L.]

I will almost guarantee your main catalytic converter is rattling. The inner part falls apart on the Aerios and starts to rattle. You can check this easy. Crawl underneath and hit it with a rubber mallet or with your hand even. If it makes any banging sounds it's no good.

Also problems are the small heat shields that are clamped to the exhaust pipes. The clamps rot off and the shields rattle on the pipe. We just cut the shields off and leave it as is. You could reclamp them if you want though. Also, the tin heat shield around the exhaust manifold on the motor might be rattling too. It is designed to be loose, however you can put a few "cinks" in the tin to make ti more rigid and less prone to rattle.

I haven't seen a 2.0L or 2.3L Aerio motor with a noisey timing chain - and I've seen some that are horribly maintained.

[ewetho]

If it seems to be the engine actually look at the bracket at the bottom of the primary Cat. Right there at the oil filter and O2 sensor. I find either the bolt holding the two parts together or the one to the block to be missing. Normally first found in reverse.

If it seems to be under the car the secondary cat is a problem that continued to the SX4. Futaba what gives????

Other source is the heat shield in the bend just before the rear axle. That likes to rust out the clamps.

[drtyd1]

Originally Posted by Jeff L.

Also problems are the small heat shields that are clamped to the exhaust pipes. The clamps rot off and the shields rattle on the pipe. We just cut the shields off and leave it as is. You could reclamp them if you want though. Also, the tin heat shield around the exhaust manifold on the motor might be rattling too. It is designed to be loose, however you can put a few "cinks" in the tin to make ti more rigid and less prone to rattle.

I took the car to an exhaust specialist, and he actually tore the heat shields right off seeing as that was the easiest solution. My baby is still making some noise though. Its driving me nuts! Looks like I'm taking a rubber mallet to the cat converter!

[drtyd1]

VERDICT: I found that the primary cat was completely shot. There was a hole running right through the interior filters. Extreme heat from the engine caused it. To get the part replaced at a specialist was about 500.00$ for parts, labor, and tax. They have to mail in my bad cat before they can receive the new replacement. This means that my car has to sit in the shop for 5 days Waiting! ...and it all started with a little rattle...

Does this price sound reasonable to anyone that knows about the exhaust system?

[fellowking]

My 2004 Aeriohad the same problem 'catalytic converter'. Lucky, my car 'catalytic converter' still under warranty '80,000Km or 8yrs', therefore, the dealer changed the part for me.
However, my car had other problem 'ABS light ON'. The dealer said it was the speed sensor failed. It cost around $200, too bad.

[carthell]

Originally Posted by ewetho

Other source is the heat shield in the bend just before the rear axle. That likes to rust out the clamps.

There isn't a replacement part on the market? I need to replace mine. (I can't imagine the part being installed there for no reason at all.)