2001 Discovery II with about 155,000 miles on the odometer. The engine was replaced by the previous owner with a low miles engine at about 100,000. I have no idea how many miles were on the replacement engine. I have an oil leak that I know I need to work on. I think it's the front cover. I have a complete set of new pulleys, tensioner, and belt that I'll put on when I have it apart. But now I have a new noise. Inside everything sounds normal. When I run the engine with the hood open, it sounds normal. But if I listen by the driver's side wheel well, it sounds like a diesel engine. What could it be? Thanks.

 

You could have a leaking exhaust manifold on that side.


Where the manifold meets the exhaust pipe, see if you can feel any exhaust leaking out... it can be hot so be careful.

 

Where the exhaust manifold meets the y-pipe? I'd thought of that. It's quiet when it's cold, but get noticeable as it warms up. I just need the time to work on it. Thanks.

 

or where the manifold bolts to the head. I have had those little bolts strip a couple of times