Oil pressure worries

[Danblez]

Ever since I have had my Chim the oil pressure has been healthy but a little erratic. Often during journeys it varies by around 10psi (i.e.at a steady 70 it can be 40-55psi) and I haven't taken much notice of it. However I took it out at the weekend and pressure was consistently lower than normal and was behaving more strangely, primarily dropping during acceleration and dropping to as low as 30psi at 3-4k revs. There was also very little difference between tickover and 4k revs 30-35psi. This started to concern me so took it home and put it back in the garage.

Oil is virtually new and full and looks clean and healthy, engine sounds spot on as usual.

I am convinced it is the gauge or sender but would appreciated your collective view.

Also what is the easiest way to check? Throw a new sender on it?

[ClassiChimi]

I have a similar issue sometimes,,,, mine is a bad connection at the oil pressure sender terminal, it sometimes works loose and has actually fallen off on one occasion,,, I've carefully nipped the terminal and re pushed it onto sender and alls been well since. Erratic gauge readings etc most likely a bad connection somewhere,, or that's where I'd start looking,

[Danblez]

Thanks, I will have a poke at the weekend, where is the sender located is it obvious?

[ClassiChimi]

Hi, you'll need to jack the car up as high as possible or use a ramp, scrabble underneath the engine, you'll see the cross braces that strengthen the chassis,, the rear Offside diagonal bar should have the wiring cable tied to it,, look for the engine sump,, you'll see a round silver object with a spade connector screwed into the sump ( that's the oil pressure sender ) check the wires going to it and the connection, it's probably a good idea to gently work it off the terminal, clean and check etc and re apply, it's just a good idea to discount this as a problem. You could have a tired sender but the wiring is well worth checking first.

[Danblez]

Cheers, it looks like its the sender, fingers crossed.

I spent hours last night reading every thread on PH trying to find out what ohm and PSI range is correct for the silver rimmed cearbont gauges and found conflicting info.

I think it is 240-33 OHMs and 0-100PSI may be correct can anyone confirm?


I also think it is a smiths gauge which works the opposite way around to VDO ie. 240 ohms=0psi and 33ohms=100PSI.

Thanks