shark13

Hello,
I have a 99 RX300. This morning, when returning from dropping my daughter off, I heard a loud sound on the passenger side of the engine. Not quite a squealing but similar. It lasted for only about a second or two and then stopped. Later, my wife experienced stumbling on the drove home up the hill. I test drove it as well and would describe it as not fully engaging and catching. It's not as if the car doesn't move, but it stumbles up hill...even the slightest.

A bit of history. I replaced the timing belt around 10 months ago. I recently noticed a tapping sound near the intake. It matches the RPM's of the engine.

My first concern is the timing belt may have jumped a tooth or two. Any other thoughts? Unfortunately no error codes are being thrown as of yet. As a result I'm a bit in the dark.

Correction: I ran a test for error codes and got two pending. P0300 and P0301. I forgot to mention about 2 months ago I had some similar issues with multiple codes of this sort. I ended up replacing the VSS sensor and the spark plug at piston 2. It would seem logical I may be having a similar problem again but the noise from the right side of the engine is what is throwing me off.

Also, I checked the plug at piston 2 and it was coated white...quite thick. It sounds like this is related to ash build up from excessive oil, heat, or both?

Thanks,

shark13

It turned out to be just bad spark plug (#1). While I haven't seen sludge on any of the plugs in the front (2,4, and 6), plug number 1 had a large amount. This plug is nearest the PCV valve. Guess it's definitely time to replace the back valve cover with an newer model.