Loud Idle

[wkucardinal]

Hi. My 2003 Corolla has a loud idle when first started. It only does it when it's in gear (Reverse, drive, etc.), but not in neutral or park. After I drive the car for about an 1/8th to 1/4 mile it stops making the noise and has a quiet and normal idle. It also, of course, doesn't do it when I'm driving. It stops as soon as i accelerate. It's not a metallic noise. It sounds almost like something is loose and rattling but it doesn't make sense that itw ould stop doing it after it warms up. The sound is comingf rom under the hood, not the exhaust that I can tell. It's not the fan belt but I wondered if it may have something to do with the idler. But, once again, it doesn't make sense that it would stop after driving long enough for the engine to get up to operating temperature.

Any ideas?

-B

[NiceSR5]

Is it louder like a blown muffler or sounds like higher rpm's? loud in front it might be your exhaust manifold maybe cracked making a a louder noise in front when cold and a quieter when car is hot

[Bitter]

like a lawnmower?

[ghost_ryder35]

i'll take a shoot in the dark, how bout a tranny fluid change, cant hurt right?

[Raddman]

Originally Posted by wkucardinal

Hi. My 2003 Corolla has a loud idle when first started. It only does it when it's in gear (Reverse, drive, etc.), but not in neutral or park. After I drive the car for about an 1/8th to 1/4 mile it stops making the noise and has a quiet and normal idle. It also, of course, doesn't do it when I'm driving. It stops as soon as i accelerate. It's not a metallic noise. It sounds almost like something is loose and rattling but it doesn't make sense that itw ould stop doing it after it warms up. The sound is comingf rom under the hood, not the exhaust that I can tell. It's not the fan belt but I wondered if it may have something to do with the idler. But, once again, it doesn't make sense that it would stop after driving long enough for the engine to get up to operating temperature.

Any ideas?

-B

Same thing happens with my 03 at cold idle after 4 years it revs high and sounds like a truck, its normal just live with it, someone explained it to me once but I forget...

But I have the same rattle from down under somewhere, sometimes its not there other times it rattles a lot...Mostly at start up in gear both reverse and forward...after it warm up its gone...

I will have it checked someday but its not that annoying that I can't live with it...I really think its only a loose heat shield or something, nothing serious because it hasn't gotten worse or caused a repair!

Good luck if you find out what it is let us know, I will do the same

~Radd

[REN69]

If it's a rattly metal sound with the idle is high, most likely the heat shields rattling because they're lose.

[wkucardinal]

That's the thing. It doesn't really idle high. When the car is cold in neutral and the idle goes up to (presumably, i dont know a lot about car engines) to heat up the engine, the sound is gone. The sound ONLY occurs after I shift it into gear and the idle drops. Once I hit the gas the sound goes away.

I would characterize it as almost a gurgling sound.. but not exactly. It's almost like a deep rhythmic grunt - like a motorcycle. It's loud enough that everyone around can hear it. Other than it being slightly embarassing it's not a big deal. The car is running superbly and as far as I can tell it hasn't affected any other component of the engine.

[ghost_ryder35]

you should record the noise for us and post it up here, thats the only way we will be able to help you out anymore than we already have

[REN69]

Yeah, it's really hard to figure something out when you can't hear or see it.

[wkucardinal]

good idea i'll do that