My 1996 Toyota Camry LE V6 with 187,000 miles has started making noises from under the front valve cover on the passenger side.
The sound started as a tapping sound. I changed the oil and added a bottle of Risoline and the sound went away after 5 minutes of idle. Unfortunately new sounds returned in a few days.
The sounds have changed over time from a tapping sound, like a lifter, to a kind of scratching sound or psst psst sound. Sometimes there is no sound. Sometimes it the sound is a louder and rougher sound.
I changed the oil again after 500 miles and this time I put in a bottle of Marvel Mystery Oil (no Risoline). I didn't try an engine flush as I was worried about possibly releasing too much gunk at one time.
No check engine light. Changed the PCV valve.
My mechanic tested the oil pressure and it read 80 psig which he thought was too high. He thinks the oil can't move out sufficiently from the pump due to maybe a plugging issue.
I wonder if I have the sludge problem that I read about for the V6 engine and maybe part of the valves are not getting enough lubrication? I change my own oil and was using Mobil 1 5W30 or 10W30 (I had seen both listed as ok). I fell for the claim on the bottle of 10,000 miles and I left the oil in for more than the 6 months than I normally would change at. The miles were just a few thousand.
We have only been using it for short trips around town since the sounds started. It has been on the freeway once and did ok. I was hoping that if I kept putting in an additive of some sort, and drove it lightly, it might possibly help. I really don't want to drive it until it fails and is worthless. I would rather let someone else do that. It is still a nice car with an ok transmission.
I live in California and the smog check is due for the registration. If old cars don't pass smog the state will buy them for $1000. We don't know if this condition will cause it to not pass smog. I would rather try to keep it going.
Any suggestions would be appreciated.