[RickJ]

2002 Ford Explorer. Oil level is good.

When I start my car, my oil gauge stays buried all the way to the bottom for the first 5-10 minutes of driving. While it's buried, the "check gauge" light is lit.

Generally the gauge "pops up" to where it's supposed to be after 5-10 minutes and the check gauge light goes off.

I'm presuming it's nothing to worry about: just a sticking gauge... but wanted to run it by the experts ;)

Am I right?. or should I have it checked out?

[TxGreaseMonkey]

I would have it looked at right away. It's dangerous to ignore any gauge, as many accident investigations have revealed after plane crashes. Closer investigation could indicate, for example, journal or other bearing wear, causing oil pressure to drop. Valves and camshafts are the last on the oil train and the first to normally show damage from low oil pressure. Remove the oil filler cap and look at the surface of the camshaft. Do you observe scuffing or do they have a mirror finish? Run your finger over the inside of the valve cover and see if it indicates heavy varnish or sludge buildup. This could be a tip-off of possibly heavier sludge in the bottom of the oil pan, which is affecting oil pressure. It's important for oil pressure to build rapidly, particularly when the engine first starts. This is when 90% of the wear to an engine takes place.

There are several other possible causes of low oil pressure:
. Using improper oil weight. Ford recommends 5W-20 weight oil for most of their newer cars. I would not use anything heavier than 5W-30 in your Explorer. One reason I recommend full synthetic engine oil is because oil pressure builds 7 times faster than conventional oil. This is particularly important in climates where winter temperatures drop below 0 degrees F. Synthetics also keep engines much cleaner inside and provide a higher margin of protection.
. Oil pump worn or damaged.
. Clogged oil filter.
. Clogged oil strainer.
. Oil pressure gauge not working properly.

It's noteworthy that the Check Gauge Light corroborates the oil pressure gauge. I would remove the oil pressure fitting, temporarily install a hand-held gauge, and see what the oil pressure reads when the engine is first started during the day. Oil pressure should likely be between 40 and 60 psi, at 2500 rpm.

Years ago, my wife ignored the idiot light coming on, when she was driving around the beltway in Washington, D.C. It was a costly mistake. The 7 and 8 rods went first, followed by the crankshaft. The whole engine had to be rebuilt, while we were in the process of moving to California.

[Zipper]

It would be worth, imitially tracing the sender from the rear of the gauge to the location on the block, this will be a small screw-in sensor and it's not uncommon for this to get clogged with a piece of floating crap. Removing this and cleaning it thoroughly could save you a big bill - it's a cheap first step, anyway.