Q: I bought a 2004 Ram 1500 with the 3.7-liter V-6 a year and a half ago, and never had any real problems. Now the check gauges light has been coming on, and the oil pressure gauge sits at zero when at idle. When I'm driving the gauge comes up and the light goes out. There's no noise and it runs fine.
A: Depending on the Ram's condition and mileage, you want to be careful how much money you invest. But start with the basic checks. If the problem began after a recent oil change, change it again with an OEM filter. Some aftermarket oil filters will restrict flow. Also pull the oil-fill cap and look for signs of excessive sludge built up around the valves. Then, either you or your local tech must test the oil pressure with an accurate oil pressure gauge. Install the gauge at the oil pressure sensor port. With the engine hot/idling (in-truck gauge reading 0), the gauge should read a minimum of 4 psi. If the pressure is good, the problem is in the sensor, gauge, or circuits. If the pressure gauge reads 0, it's an internal mechanical failure. Again, do you want to spend the money? I wouldn't take any long trips, but you could still get a few more miles out of this engine. The internal cause could be worn bearings, but it's most likely the oil pump, because of the lack of engine noise. It's a significant repair that requires removal of the oil pan, timing chain cover, and timing chain just to gain access to the pump.
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