This afternoon I noticed my oil light on my 91 would come on when I stopped with the truck in gear. In neutral, the light would go out. The gauge on the dash dropped a little like it normally does but still in the normal range. Has anyone had this issue and what may be the problem? Thanks.

 

Could be a few things - too slow of an idle speed, bad oil pressure switch, or low oil pressure combined with a bad oil pressure sender. I'd put a cheapo mechanical gauge on temporarily to make sure the pressure is OK. My bet is that the idle is set a little slow, though.

 

I noticed in the Chiltons manual the sender has two circuits. One for the gauge and one for the light. Is there a good place on-line to purchase parts like the sender? Also does any one know what size extra deep socket I need to do the job?

 

If your sender on the 91 is in the same place as my 92, drivers side of block, I'd just use a pair of channel locks, get you a brass Tee and close nipples, install Tee and re-install sender, you can then pipe gauge to the other side of Tee and keep your light and factory gauge as I did. I've been told that the Dodge gauges are not know for being very accurate. My factory gauge normally runs half way between the first and second mark and rarely moves, but motor holds 25-30 psi in drive @ 700 rpm and 35-40 in park.

 

Had the exact same thing a couple years ago. I raised the idle, thinking that I was really having low pressure. It kept getting worse until I was idling at about 1100rpm. Replaced the sending unit and dropped the idle back to where it should have been. Never shown low oil pressure since. It is cheap, easy and likely the culprit.

Carl

 

Carl20320, Is the sender dodge or cummins? How much?

 

i got one at advance a coulpe months back for about $16

 

I bought mine from the dealer back 5 years ago (before I knew Cummins sold parts for our trucks : :-[ ) from the dealer. It was about $20. Easy to change with just a crescent wrench or channellocks.

Carl

 

Bought an oil pressure switch. Installed it. Took the truck for a long ride.


OIL PRESSURE SWITCH BY STANDARD - $23.00
LABOR TO INSTALL - 15 MIN
NOT SEEING OIL PRESSURE LIGHT ON - PRICELESS

Thanks for all the info to solve this issue. Hope it lasts.

 

Glad to hear that was all it was. ;D I would hate to hear what the cost would be if it had been an oil pump or something similiar.

A great big SIGH!
Carl

 

If anyone has any doubts about the bad sender issue I want to tell them to change it before you do anything else. Just paid 33 bucks for a new one and what a relief! Red light used to come on at a fast idle - even after a gentle city drive. Guage would indicate good pressure. After a good highway run with the 5er, the red light would come on at fast idle AND the guage would plunge to zero. The highest pressure ever shown by the old sender is lower than the lowest ever indicated by the new one. ;D

With the winter coming on (standard tranny of course) the rather rapid idle is good so I will leave it where it is. By the way, has anyone come up with a better way of adjusting the idle on a VE? I use a long screwdriver and a small hammer to loosen the nut. There should be a better way.

 

Uh, how about a long screw driver and a BIG hammer or a pocket full of money for all the fancy tools ;D

 

Hmm. Is that what the pro's call a "BFH" - loosely translated as a 'darned big hammer'? ;D

Took the old beast for a run today. How could anything as minor as a light and a guage make a person so happy. Love that past the halfway oil pressure reading.