I always encounter a groaning noise (not a whine) on cold starts that eventually stops after a minute or so. I've grown used to it, but the recent low temperatures have lengthened the time it groans in the morning. The sound is very much like the cavitation that occurs when the intake of a power steering pump has a leak to atmosphere. I learned a couple of things about the noise...
One is that it's a very common observation reported on the Jeep and Chrysler forums, but not much here. I wondered if anyone has noticed it?
Another is that I traced the groan to the oil pan. You can really feel the vibration when touching the bottom of the oil pan. If you press a palm across the oil pan, it greatly diminishes the sound.
I'm thinking cavitation originating from the oil pump intake tube. Any other ideas?
One is that it's a very common observation reported on the Jeep and Chrysler forums, but not much here. I wondered if anyone has noticed it?
Another is that I traced the groan to the oil pan. You can really feel the vibration when touching the bottom of the oil pan. If you press a palm across the oil pan, it greatly diminishes the sound.
I'm thinking cavitation originating from the oil pump intake tube. Any other ideas?
