560SL oil pressure sending unit

[Omaha 560SL]

The oil pressure guage in my 1988 560SL has been pegged whenever the engine is running since I bought the car in April. I assume this is just a bad sending unit, but how difficult is it to replace?

[abiby]

As I've never changed one I can't say as to ease of replacement but....

I also can't tell from your description if you have a problem. Typical for these cars is:
When you turn on ignition, pressure should be 0.
When you cold start the car, pressure typically pegs to maximum.
When the car is at operating temp and at more than idle pressure is near or at maximum.
When the car is at operating temp and at idle, pressure can be as low as 1/3 of scale.

[ewenjo]

What Abiby said is what I was told and how the oil pressure gauge responds on my 82 380SL. Off and idle is at 0, running the unit is at max. I changed my unit when I first got the car as there was no response. Changing is simple. The unit ( on the 380SL) is on the front RHS lower side of the engine. It is a cylindrical object about 1.5 inch dia and just screws out. I did find that I had to make sure the unit is primed with oil to eliminate an air pocket. Simply put oil in the unit before screwing it in.

All this said , your unit is probably operating okay.