Hi, gang:

I have an 89 Grand Caravan I've been nursing along for a few years.
Great chassis and body, but it's on the third tranny and second
engine. Van has 204,000 overall, with about 120,000 on present 3.0
liter engine.

Oil pressure has been fine for the past year. I just had the oil
changed at a local garage, however, and they used 5W30 oil, where I
have always used 10W40.

I noticed that, after the switch, that the oil pressure gauge would
read somewhat lower than usual when the engine was hot...and after
three weeks or so, the gauge started reading VERY low at idle when
warm.

Today, on the way home from work, when I was coasting up to a corner
at 10 MPH or so, the oil pressure plunged to zero as I turned the
corner to the left. It did the same thing when I hit the brakes while
coasting at low speed.

If I hit the gas a bit, the pressure perked up, but never came close
to where it used to read (half scale or slightly greater).

I thought I might be low on oil, but when I checked it, it was okay.

The engine never made any clicks or clattering noises during the low-
pressure events, but it can't be a good sign....

1. Will changing to a thicker oil help?
2. Is the oil pump gone bonkers?  If so, is it worth replacing?
3. Bad sending unit?

Did I mention that, while intelligent and good looking, I'm in a
severe poverty phase at the moment? And that if the solution costs
more than a measly, moderate amount, I'll be walking?

Any ideas will be greatly appreciated.

Thanks,

--KK in MN