need to purchase new injector tips but may have to wait a week to purchase due to budget constraints. is it safe to drive a diesel with worn out bosch tips (sounds like ball bearings banging around under the valve cover)??

If you are having that sound and the sound does not improve after the Engine warms up I would be thinking the sound is not being caused by the Injectors.

Also an Air leak in the system can also cause a lot of noise as it causes erratic Fuel Delivery. You might change your Fuel Inlet Hoses. Won't cost much. On a 123 it would only be a few dollars for the hose (5/16 SAE 30R7 Fuel from any auto part store).

It would also be nice to know the year, model, and milage of your car.

I would say that in general it is safe to drive with worn Injector Nozzles but everthing has a limit to it. Fuel not atomized well will burn at a time and a place where it is not supposed to burn. If that problem goes on long enough it can cause damage to the Precombustion Chamber; if parts of the Precombustion Chamber get down into the Cylinder it can cause damage there also.
I guess what I am saying is that if you do not have the money for the Nozzles right now you are taking a gamble. It may be that the odds are on your side.

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84 300D, 82 Volvo 244Gl Diesel

it is a 1984 300DT.