1991 Camry, 3SFE, Auto, 115,000 miles During the last 2 years, there is a noticeable knocking sound from the engine while it is idling after a cold start. When the engine is hot, it is relatively very quiet. I cannot hear the knocking when the engine is hot even when I rev up the engine. The oil pressure warning disappears a few seconds after start-up, and the knocking decays slowly after about 2-3 minutes. Since I had the car, I changed the oil every 3000-4000 miles, but my concern is that there is some buildup inside since I found some buildup inside the oil cap (is this a valid indicator?).
- Would you recommend on flushing the engine?
- remove the oil pan for inspection?
- change to a different type of oil filter (I use pure-one)?
- ignore the start-up knocking because a. overall everything else is fine, or b. there is nothing much to do about it?
- Any other suggestions?
I use 10w40 in the summer and 10w30 in the winter (Southern CA), regular dino branded oil. Should I switch to a specific type/brand?
Thanks in advance.