Hi folks,

I am having a rather troubling issue with engine noise on my 1992 ES300. When I am driving and get the engine around 2250 rpm, there is a rattling noise that comes from the engine. The noise goes away when I get past this rpm range, but does it in every gear. However, the engine only does this under load and only while accelerating; I cannot reproduce the noise in park or decel. This noise started about two weeks ago. It doesn't sound to me like the typical rattling associated with rod knock, it sounds more like the engine is just revving much louder than it should at this rpm range. There is no observable loss in power associated with the noise and my gas mileage has been relatively unchanged since I bought the car 3 months ago.

As far as the car goes, it has 136,000 miles and has otherwise been great since I bought it. It was well-maintained by the last owner, and since I bought it I have changed oil and coolant. I have yet to change spark plugs and distributor cap & rotor. There has been a slight oil leak/burn since I bought the car but I have kept it topped off pretty consistently.

I would upload a video but have yet to capture the noise nicely since the driving noise covers it up on video. Any help would be much appreciated.

 

Check for loose or rotten exhaust parts. It sounds like an exhaust shield has come loose

 

Wanted to give an update and also embed a video to see if I could get any additional insight.

This past weekend I changed the tranny fluid and checked every which way for any loose exhaust parts and it appeared solid. From doing some further research I'm wondering if it could possibly be a bad cat. If it were an oil bearing, I am assuming it would not be RPM-specific, and increase proportionally with engine speed, correct?

In any case, I have posted a youtube video that captures the noise fairly well (aside the heater vent rattle). Please post if you have any insights. TIA.