the other day, i noticed that my oil pressure was like at 5 or 10, so i went and got my oil changed and had this oil extender that begins with an L, like Lucas or something, i can't remember the name but i got it at a parts store. anyway, when i first start up my car and drive it a little it's at 40, and as i drive longer, the pressure goes down to like 10 again. what could be the cause of this? i kinda think that the oil should have been topped off, then that stuff put in, but they topped it off with the stuff as well. could that be it, or the 30 grade of the oil?

 

I had the same problem with my '92 RS. The gauge showed real low oil pressure. It turned out to be the oil pressure sending unit. When I took off the old one(it was a pain in the butt to get off), I noticed that it was leaking oil from where the electrical connection is. Put the new one on and problem solved. You could have the same problem; or it could be a problem with the wiring, gauge, etc. I just took a shot that that was the problem with my car.

 

 

DITO I had exactly the same problem on my 92 rs 305 w/99,000 miles on it.New sending unit was the fix ($28.00)Had the same oil leak to. I put it on jack stands and wen't at it from the bottom. The only tool that worked getting the old one off was chanel locks. you'r old unit should come out easy they arent put in real tight. just be patient and keep saying to yourself- I love my car-I love my car-I love my car! good luck.

 

where is the sending unit, and how can you tell if it's bad, or just something cheap to replace anyway? lol. thank you for the responses guys.

 

Since I ahve the exact same problem as you right now, I got enough responses from people to sort of figure it out.

The pressure sending unit is located on the DS to the rear of the intake. It kinda tucked under the intake and has a weird plug going into it. I hope I'm lokking at the right hing casue I got to replace it too. Can anybody verify this?

 

On the 305 and 350 block the sending unit is about 2" above the top of the oil filter. there is a 3 wire conector with a rubber seal. I cleaned mine with wd40 outside and in the conector to get the oil out and help water proof it. realy should use di electric grease but didn't have any.