Oil Pressure light coming on over bumps

[johntom]

Hi

i have just bought a 1985 350i with under 30k from new. I drove it home (200 miles) and all seamed fine. The oil pressure travelling at 70mph was on the 3 (3 Bar?), is this good? When i drove into my village at the end of the journey, i slowed right down to drive a series of speed bumps - as i did the oil pressure light flashed on? any ideas as i am completely new to Tvr and the V8.

many thanks

[rev-erend]

my guess would be an electrical connection being dirty or loose..

check the wires and use an electrical spray cleaner ..

Not sure what car you have as it's not in your profile.

[mightymouse]

rev-erend said:

my guess would be an electrical connection being dirty or loose..

check the wires and use an electrical spray cleaner .

Low oil level ?
Not as silly as it sounds

[TVR 3X]

Assuming that you check your oil level is correct and that the level on the actual gauge doesn't flatline when you are going over bumps.

In these circumstances then it is likely that it is the wiring to the oil pressure sensor that is faulty.

The oil sensor is down at the front of the engine on the left when viewed from the front.

Check what type of circuit (and the wire colour) by disconnecting the wire from the sensor then turn on the ignition.

If the light stays off then you are looking at a circuit that closes when the oil pressure is low - confirm this by temporarily earthing the wire and see if the light comes on. You then need to check this wire back to the dashboard for somewhere it could be shorting. If all else fails you could run another wire, Wedges are not complex enough that the oil warning light does anything clever (not my 1985 390 anyway).

If the light is on with the wire disconnected then you need to be looking for a break in the wire going over bumps (or you have disconnected the wrong wire).

Russ