Hi Folks,

I have a 1999 Ford Explorer SUV 4x4 with a 4.0L engine. I noticed that
when the weather gets cold, when first started, the oil pressure gauge
needle does not jump up to it's normal position but stays laying down
like it is when shut off. I started to notice this happening last
winter. Check eginine light illuminates as well. Once engine warms
somewhat or maybe just the engine compartment, needle jumps to normal
position and check engine light goes out. I can usually drive about a
block and it straightens out, but have to drive it further, sometimes a
kilometer in colder subzero weather. When this happens there doesn't
seem to be any excess noise from the engine like it's lacking lubricant
or anything.

Now, this only happens when the weather gets cold. Normal summer time
operation this doesn't happen. It's different than just cold engine, it
seems to be directly related to weather temperature, and I start to
notice it at about -2C and colder. Usually after sitting overnight.

I'm thinking that this is probably a faulty oil sending unit, if
changed, this problem should go away. Would this be the correct thinking?

Thanks

Allan