Name that noise.

[DieselPaul]

Just test drove a 1991 300D 2.5, potentially for my father.

It has 203,000 on it, full to the mark with oil, full to the mark with green, clean coolant (yeah I know its green, but it wasn't oily green), new Nissens radiator, etc.

The car started pretty easily, no smoke, the car broke down on the test drive however any they had to jump it, and after cranking on it for a while not letting it charge up it did cough a little light colored smoke on startup, but a very minute amount.

However, the car makes a ticking noise that gets louder with the RPMs. I shot a video, window up, window down, sorry for the noise, but you can hear it in there.

Do nailing injectors get THAT loud?

Laying under the car I seemed to hear it a bit louder, do diesel exhaust leaks sound like gas exhaust leaks?

Or, am I hearing a rod knock/serious valve noise?

Also, do 90-93s have some sort of electronic throttle? While I was driving the car just fell to idle and wouldn't rev up. I popped the hood and pulling the linkage under the hood on top of the valve cover it wouldn't rev. So I called the dealer he came down, and the car wouldn't restart, the battery was dead. He jumped it and it would rev again. I imagine the alternator is bad, the battery was new.

When it started he revved on it and it black smoked a bit, but no blue smoke or white.

Here is the video