OK this gets a little further down in the weeds as it applies to 3500's with serial numbers earlier than + - 700. My car #708 has an internal high pressure pump but #686 - 10 cars later - has an external high pressure oil pump. The early cars were equipped with an external high pressure oil pump mounted in front of the engine. (I am not talking about the scavenger pump that pumps oil to the oil cooler as fitted to cars latter than 700.) I am wondering if others have experienced this particular noise. The noise sounds like a surging sound or a slight vibration. the noise appears when cold and on start up but goes away at about 1000 rpm's. I am guessing that the noise is caused by oil entering the check valve in the external mounted oil filter located on the right front fender well or on some cars mounted under the carbs. This is only a guess, so I would be very interested in what others have experienced. Ivan, I know your Vignale has this external oil pump. What say you. Ciao, FGM PS I am pleased to report that the white paper on my garage floor under 686 has yet to receive 1 drop of oil or water. I am keeping my fingers crossed.
Frank, I had a Vignale spyder with an external pump that would make a noise at low rpms and you could feel the vibrations on the oil lines. My current one does not make the same noises but the oil gauge jitters as though the oil pressure was fluctuating quickly +/- 5 psi. The oil gauge on the other car did the same thing. Is your oil gauge steady or does it jitter? Ivan
