I had a mechanic who, although he is highly regarded as a premier Subaru expert, is human and misdiagnosed my engine. He told me the engine was shot, and that I should sell my car for parts rather than investing money in repairing. While he did have strong evidence (failed compression test, knocking noise, etc.) there was also evidence to the contrary, including a perfect report from your lab. I called your lab and asked the representative how often an engine could be failing without any evidence in the oil. He strongly recommended I get a second opinion. I took this advice and hauled the car to a Subaru dealership. Within a couple hours they had it properly diagnosed and repaired (stuck oil control valve). I went from selling a $10k car for probably $1k – $2k for parts (with a $4k loan remaining), to paying $300 to repair. I paid it off and drove it for another two years, and just sold it two days ago for $7500. I can’t thank you guys enough!