I've had this truck for two years now. I use it very infrequently. I've done some work on it but nothing major. It has always run just fine. The other day I took a 15 mile round trip and on the way back I began to notice that at traffic lights while idling my oil pressure gauge had dropped to zero. At the time I was idling at about 900 RPM so I raised it to about 1100 and the needle swung back up again. As i got closer to my destination I noticed that the problem seemed to get worse. For example when rolling up to a traffic light in third gear there was no oil pressure indication and reving the engine didn't seem to help. It was only after I got going pushing about 2500 RPM I noticed the gauge once again rose to the occasion.
The engine seemed to sound a bit loud at high RPM going up the hill to my house but perhaps that was just me worrying about it. I don't know. Otherwise I made it home OK. Today I checked the oil dipstick. The first thing i noticed was that the reading was about 4 or 5 inches above the "full" mark on the stick. The other thing was that the oil seemed to be very thin as though it was diluted. It certainly didn't seem like the viscosity of the Delvac 15W40 that was used at the last oil change. This truck has never been hard to start and as far as I know at least as long as I've had it it has never been "turned up".
I had this same problem with my M37. The cam operated fuel pump on that truck has a diapraham that tends to rupture, and when this occurs it dumps gas into the crankcase thereby diluting the oil. It's a known problem. Does anyone know if there are any known problems that might be causing issues such as mine? I'm hoping that I'm not looking at a ring job here. Thanks for any advice on what this might be and in troubleshooting this problem. Lenny
The engine seemed to sound a bit loud at high RPM going up the hill to my house but perhaps that was just me worrying about it. I don't know. Otherwise I made it home OK. Today I checked the oil dipstick. The first thing i noticed was that the reading was about 4 or 5 inches above the "full" mark on the stick. The other thing was that the oil seemed to be very thin as though it was diluted. It certainly didn't seem like the viscosity of the Delvac 15W40 that was used at the last oil change. This truck has never been hard to start and as far as I know at least as long as I've had it it has never been "turned up".
I had this same problem with my M37. The cam operated fuel pump on that truck has a diapraham that tends to rupture, and when this occurs it dumps gas into the crankcase thereby diluting the oil. It's a known problem. Does anyone know if there are any known problems that might be causing issues such as mine? I'm hoping that I'm not looking at a ring job here. Thanks for any advice on what this might be and in troubleshooting this problem. Lenny
