My 2003 cavalier ls sport is making a loud noise it sounds like a lifter knocking the noise is coming from the top of the motor and it doesn't stop. I had a guy check it and he said there is oil in the intake. This car only has 77.000 miles on it.I had a oil change done about a month prior to this could they might have done something. Please help.
If the noise is coming from the top of the engine, it could be a collapsed lifter, bad cam (will cause a misfire), or excessive carbon build up on the piston / valves. If the noise is from the lower part of the engine, it could be a rod or main bearing. Remove a spark plug and check it to see if there is a lot of carbon on it. If there is, they make products to eliminate carbon from the intake and combustion chamber. That would be the cheapest first thing to try. Other than that, you need to start taking things apart to check the problem.