One problem related to engine noise has been reported for the 2007 Toyota Camry Hybrid. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Toyota Camry Hybrid based on all problems reported for the 2007 Camry Hybrid.
Engine sludge: engine started making a noise, so took it to a Toyota dealership. They inspected it said it had engine sludge. They told me I never changed my oil and I used the wrong viscosity, I used 5w30 instead of 5w20 recommended, not required recommended. Thin oil is mandated by federal standards for mileage purposes only. I change my oil every 5000 miles, and told them so. At that time they told me I needed the engine rebuilt, it will cost $8000 or 9000 to fix it. And then they voided my warranty. I have since taken the car to another dealership, I was told it had a bad coil, it was only running on 3 cyl. They replaced all the coils, they said it ran great for about ten minutes, then it started running worse than before. They contacted corporate Toyota to find a fix, they told them to cease working on it, and put it back the way it came in that the warranty was void. Since this happened I have numerous complaints on the internet about Toyota's engine sludge problems. Going back as far as 1996.