Weird Noise, unsure

[rpicard@demand-its.com]

I have a 07 yaris with 180,000km on it.

Theres a odd problem I've had for a while now but we can't figure out where it comes from.

When driving, at around 2500rpm with gas there is a noise that we can best describe as sucking milk through a straw when the cup is almost empty.

If I take my foot off the accelerator at 2500rpm the noise goes away, if I go up to 2800 rpm I can't hear it anymore.

I tend to only notice the noise in the third and fourth gears.

It may be nothing, it may be something but I have no idea what to look at.

[CoryM]

Check your coolant level. If there is air in the system it can make those noises as it passes through the heater-core (in dash). Often loudest when cold and you first bring the engine rpm up. You can also get odd noises from the airbox/intake, but they are normal. Can't hear it on most cars, but you can on the Yaris.

Cheers.

[TOLMACH]

I have a 07 yaris with 180,000km on it.

Theres a odd problem I've had for a while now but we can't figure out where it comes from.

When driving, at around 2500rpm with gas there is a noise that we can best describe as sucking milk through a straw when the cup is almost empty.

If I take my foot off the accelerator at 2500rpm the noise goes away, if I go up to 2800 rpm I can't hear it anymore.

I tend to only notice the noise in the third and fourth gears.

It may be nothing, it may be something but I have no idea what to look at.

that is normal for this engine.. everybody hears this sound (some people just do not pay attention).. i think it is caused by the intake / throttle body design