I have a 3500 2001 24v cummins stock motor with 200K on the clock but it got a new motor at some point before I got it.
For the last year I ve noticed a bit of a funny noise out of the motor from time to time, it comes and goes but it has gotten abit worse in the last few weeks. I don't know how to describe it but I think it might sound like pre igination (one of the injectors leaking fuel). You are most likely to hear it when OD is turned off crusing at 2000 RPM. Code 1693 comes and goes ( sometimes its there when I check for codes sometimes it not). I have turned the key on and off and the only code that has come up is 1693. I have read other topics on this and it sounds like I may be in trouble with the famous VP. Its been a few months since I last checked the fuel pressure but last time it was at 12 PSI with the motor at 2000 RPM. I going to check the pressure tomorrow.

Any advice or ideas?
Thanks in advance

 

Checked the fuel pressure today and it is reading 14 at idle and 10 PSI with the trans in drive holding the brakes. I pluged in the scanner and it brought up code P0216. I deleted the code and went for a short drive and the noise was coming out of the motor from low revs up to higher revs. Anyone have any ideas.

 

That p0216 is the death code for the VP. You are looking at a new lift pump and injector pump. I don't know of anyone who has been able to use their truck for very long after that code shows up.