2MCHPSI

Oh Crap, I recently noticed a light tapping noise sounding like it is coming from the bottom end of the engine when warmed up. Possible engine bearing issues. I use Mobil1 syn every 4k miles. Never checked for sludge issue, but it never leaks/burns a single drop between changes. I guess it might be a exhaust leak or loose spark plug, but this makes me wonder. This weekend it will pull a valve cover just to see what the sludge issue is if any. Then try to pinpoint the tap noise. Might be trading it in soon if it is what I think it is. 104k miles. I love this RX300!

salimshah

Look for broken or leaking flex exhaust coupling.

No sense in throwing the baby with dirty wash water.

Salim.

Lexmex

This is what Salim is referring to below.

Injectors can make a tapping noise when cold and when the engine has higher mileage.

Another area is the accessory belts, especially when cold (I notice this) can make a tapping sound.

2MCHPSI

Thanks, I will look into it. The problem is when it is Warm, not cold. Trust me, i sure hope it is an exhaust leak, but I am no rookie when it comes to working on cars and this noise sure sounds like an internal engine noise. I will post this weekend what I find when I get a chance to look into it. Not looking like a valvetrain noise either.
Thanks.

Lexmex

Other thing is suspension or plastic piece making a slight racket. I get one now and then from the front lower area, but when I go to look (having it in park) I hear nothing.

TunedRX300

Just don't sell it on the way to dealership. What weight is the M1 oil you used?