Oil Light

I’m blind and don’t drive (aren’t you lucky?) but my wife and I own a '95 Ford Windstar and last summer we had issues with coolant leaking and had to have a few head gaskets replaced. Now, when we’re ideling at a stop light or sign, the oil light goes on but as soon as we accelerate, it goes off. The manual says the light indicated either low fluids (which isn’t the case) or that the pressure within the system is low. Any ideas? The vehicle seems to run fine otherwise but I’m wondering if the oil light gauge has been set too sensative? Thanks.
Marc

Have you checked the oil level?

You can probably take the car in and have the oil pressure tested to determine if it’s within spec.

It is possible that the problem is a simple as low oil level or a malfunctioning pressure sending unit but it would be worth having it checked out to be sure if your oil is full.

How many miles? What you describe is often a symptom of an engine with worn bearings. When ideling it’s not running fast enough to keep the oil pressure above the minimum for the oil pressure light, but once she gives it some gas the oil pump can keep the system adequately supplied.

One other possibility is a bad oil pressure sensor. A mechanic can attach a pressure gauge to the system to see which is the problem.

There’s only about 70k miles on this vehicle.

Since you mention coolant leaking and head gasket replacement there’s a strong possibility that coolant diluted the engine oil. This will then wash out crankshaft bearings and lead to low oil pressure.
This means the engine’s days are numberd. Don’t go far from home.

The oil pressure sending unit could be replaced as a stab in the dark but ideally an external mechanical gauge should be connected to verify whether the oil pressure is abnormally low.

The fact it only has 70k miles on it doesn’t mean much if the above is true and things like this should be taken into consideration before even replacing head gaskets.
My gut feeling is that an oil pressure test is going to give you bad news.

Agree with all the above but, there is another possibility. You might have a clogged or defective oil filter.

If this started right after an oil change, the filter could be defective, if you are WAY overdue for an oil change, it could be clogged.

Could also be the screen in the oil pump is partially clogged. I have an oil pressure gauge on my '88 Escort and last winter I was having problems with low oil pressure. First thing I did was change the filter which didn’t do any good, I pulled the oil pan off and cleaned the screen for the oil pump now the engine has better oil pressure than it’s had in 10+ years.

First, as OK mentioned, replace the oil pressure sending switch. It’s a $5 part…

How often have you been changing the oil? As FordMan suggested, defered oil changes can lead to the oil pump pick-up screen becoming carbonized which will greatly restrict oil flow…And finally, what weight and grade of oil are you using?