Greeting pals.

2000 SE 3.0 with 161k miles. normally quiet driving, especially when below 2000 RPM, yes, I love its quietness. But...

Recently found after about 1 hr highway drive, engine groaning noise significantly increased. After 2 hrs, almost couldn't stand! It goes up and down with RPMs and quite low when RPM below 1500. I could adjust gas pedal to a certain position to neutralize the noise but just for a short while.

Yes, I DO suspect that is an exhaust leakage somewhere, but why it only happens when after long drive? local driving is just fine.

Any input is appreciated.

 

To clarify does it only make noise after driving for an hour? Or it just started making the noise after you had driven over an hour?

Any idea where mouse is specifically coming from? Engine bay? Rear? Middle? Or specific part of engine bay?

When you hear the noise again pull over and test where noise may be coming from specifically. On a 2k this is easy since you can move the throttle from the engine bay.

Could be exhaust, intake, or something from the pilot side of the engine.

 

You're actually right Foodmanry. It's getting louder and louder, local driving the same loudness now, only quieter when below 1200 RPM. Under the hood I couldn't identify any noisy section, but behind the car at exhaust pipe, very loud, almost like a sporty car.

So, exhaust pipe leakage?

 

Yes sound like it. Either a part of the exhaust rusted out and caused a leak, or you have a loose fitting from the muffle to b-section.

Check your rubber exhaust hangers while you are under there as they tend to dry up, crack, and break.