My '98 Grand Caravans (112,000 miles) oil light and warning sound come on when I sit with the brake on. (as at stop lights). It goes off if I take my foot off the brake. The oil and oil pressure sender were replaced...but one day later it's all happening again...any ideas?

Before you replaced the oil pressure sender unit, did you or a mechanic connect an oil pressure gauge to the system to measure the oil pressure while the van idled, in gear, with a foot on the brake pedal? Did you or the mechanic verify that the old sender unit was inaccurate using diagnostic testing? If not, I suggest you do both.

Your problem is either a bad sender unit (or two) or an engine with worn out bearings. Happy trouble shooting.

In addition to the above suggestion, try going someplace level and putting it in neutral without the brake depressed. Is the oil light on then? If not, while still in neutral and you touch the brake does the light then come on? If it does come on now, you may have some type of electrical/computer problem. Another test is to start off with the car in neutral, put the emergency brake on. Then put the car in drive, does the oil light come on then? If it now comes on, it may be due to the low oil pressure as described in the post above.

I just replaced my oil sending unit on my 98 Grd Caravan, the next day the wife said the oil light and chime came on again. After that I decided to test drive it. SInce I have been driving it, it has not happened again. I think that the problem has been fixed.