2002 Echo - Engine Noise

[echo_driver]

I have been a lurker here for several months trying to find a solution to my problem and decided it would be easier to join and describe the problem.

I have a 2002 Echo, automatic with 194,000 miles. It has developed the following issue. The engine makes what sounds like a pinging/rattling noise under the following conditions:

1) When it is cold or wet out and the car and is idling. Noise gets louder when either I put on the AC or put in Reverse or Drive. Noise continues under light acceleration, usually subsides under hard acceleration after downshifitng, and becomes less frequent as car warms up. The noise is accompanied by slight hestitation.

2) When it is hot out, noise is present under light acceleration and is more prevalent when AC is on, along with slight hesitation.

The CEL has not come on. Once the engine warms up it appears to me that the issue is related to load on the engine - light load produce the noise, heavy load does not - though the noise may be drowned out at heavy load due to other engine noise.

I have tried the following things based on info from the board:

1) Cleaned MAF sensor using CRC MAF cleaner - no effect
2) Replaced sparkplugs - no effect
3) Checked intake hose between airbox and intake, visually inspecting for carcks - I was not able to find anything.
4) Cleaned the small screen for VVTI - no effect

Gas mileage has not decreased significantly - still get ~36 MPG with combination of highway/city driving and ~40 MPG with highway driving.

Any ideas of what else to check? Some have suggested sparkplug wires, but being that this has individual coils not sure if that could be a cause.

[2005RS]

I've read on a forum about another guy with a similiar issue, but I don't think he's solved it either.
Obviously it can't be spark plug wires(there are none), but could it be one of the coil packs giving a weak spark? I don't know how they are tested.

Originally Posted by echo_driver

I have been a lurker here for several months trying to find a solution to my problem and decided it would be easier to join and describe the problem.

I have a 2002 Echo, automatic with 194,000 miles. It has developed the following issue. The engine makes what sounds like a pinging/rattling noise under the following conditions:

1) When it is cold or wet out and the car and is idling. Noise gets louder when either I put on the AC or put in Reverse or Drive. Noise continues under light acceleration, usually subsides under hard acceleration after downshifitng, and becomes less frequent as car warms up. The noise is accompanied by slight hestitation.

2) When it is hot out, noise is present under light acceleration and is more prevalent when AC is on, along with slight hesitation.

The CEL has not come on. Once the engine warms up it appears to me that the issue is related to load on the engine - light load produce the noise, heavy load does not - though the noise may be drowned out at heavy load due to other engine noise.

I have tried the following things based on info from the board:

1) Cleaned MAF sensor using CRC MAF cleaner - no effect
2) Replaced sparkplugs - no effect
3) Checked intake hose between airbox and intake, visually inspecting for carcks - I was not able to find anything.
4) Cleaned the small screen for VVTI - no effect

Gas mileage has not decreased significantly - still get ~36 MPG with combination of highway/city driving and ~40 MPG with highway driving.

Any ideas of what else to check? Some have suggested sparkplug wires, but being that this has individual coils not sure if that could be a cause.

[Mr. Green]

I'm not a vehicle expert, but it sounds to me like to have something either not very well tightened or just plain loose. From the ping/rattle sound I'd say that it has to be secure on one end.

I'm assuming that it is only audible inside the car when the engine and road noise are lower. Perhaps a loose cover or heat shield? Do any maintenance lately? Or have any done?

Best guess. Good luck.