I took my 2006 Cadillac Cts into a GM dealer for a recall. They also changed the oil. Ever since they changed the oil, my car has been burning an excessive amount of oil. I had to put a quart of oil or more about every 500 miles. I put in 1 1/2 quarts on a Wednesday and on a Monday my car began making a loud knocking sound in the engine. GM will not listen to me and now my car probably needs a new motor. I have babied the car and this is not my fault. Oil is in the car at all times and it should not throw a rod with oil.

- Ripley, TN, USA

Timing chain broke while cruising on highway, 70mph. Incident caused catastrophic engine failure requiring entire engine replacement, $8500. Odometer 66,998. 2006 Cadillac Cts, 3.6L V6 engine, rwd.

- Jacksonville, FL, USA

My 2006 Cadillac Cts with a 3.6L V6 started burning oil excessively at about 25,000 miles. It now has about 31,000 miles and burns a quart every 800 miles. I drive about 6500 miles per year, mostly in short distance city driving. The car still drives well and it still passes the Texas vehicle inspection which includes emissions testing. The oil gets black quickly after a change. This oil consumption is excessive for such a low mileage car.

- Garland, TX, USA

My 06 Cadillac Cts had less than 35000 miles on it and less than 3,000 on an oil change when I noticed the oil level was below the reading marks on the dipstick. No drips on the ground. After researching I discovered their spec is to burn 1 quart per 1000 miles (1 quart per 500 miles if aggressively driven). I took the car in for an evaluation to see if it hit their "specs", and the service manager performed an oil change, and set me up for a reinspection at 2,000 miles. When I went in he checked the oil level, and it was low, I asked where the level should have been on the dipstick and he gave me a range. If the consumption rate is so specific, shouldn't the test for consumption have strict guidlelines about where the dipstick readings should be? I have owned almost exclusively GM vehicles for most of my adult life. Even in the ones I've kept for 150,000 miles plus, I have never had even one of them leak let alone burn oil at this rate. In 3000 miles, I have to put 2 quarts of oil in this vehicle, and that's normal. It may not be a safety issue, at least until my car engine seizes on the highway from lack of oil, but it is def something that needs to be addressed by GM.

- Troy, MI, USA