Is There A Connection Between Coolant And Oil Pressure Guages?

[Masekwm 2]

Fired up my 8v for the first time a couple of months yesterday, but oddly, the oil pressure guage reads just under max which it didn't before.

 

After sitting pondering this, and the coolant warmed up, I popped the car into first gear and rolled out of the garage, the pressure guage went to max and then when stopped it dropped down to just under.

 

Odd I thought, I turned on the lights of the car and both guages moved up the scale.

 

So I turned off the lights and they both dropped.

 

By this point I was slightly concerned

 

If I turned on the heaters the guages rise, any electrical load seems to effect the guages! I've never had any kind of problem like this before so I'm baffled. Does the oil pressure sensor trigger the stop light when it gets too high? As the stop light stayed off which made me think it was electrical rather than my engine has gone poop.

 

[readyfc 0]

It could just be that as you increase the electrical load on the engine, turning on lights heater etc., the revs will go up which will in turn increase the oil pressure slightly as the pump spins faster.

The higher revs will also increase the coolant temp slightly but that would take a few minutes to occur, so if the coolant temp is rising instantly it can't be that, but if it's taking a few minutes to rise it could be that.

I believe the oil pressure warning light is only triggered by low oil pressure not high.

[Masekwm 2]

Yeah, it's an instant movement, both gauges move instantly with load

[tagy 1]

Hi Keith, I had the problem problem with gauges going up when I turned the lights on. Replacing the earth lead, and cleaning up the earth points fixed it for me.

[readyfc 0]

In that case it could well be an earth fault.

 

edit: Too slow, I'd agree with tagy above.

Edited July 27, 2009 by readyfc

[Masekwm 2]

Hi Keith, I had the problem problem with gauges going up when I turned the lights on. Replacing the earth lead, and cleaning up the earth points fixed it for me.

 

Which earth lead would be the problem? I was at my garage tonight when the rain came down so drove the car back, it drove normally but the oil pressure was above max...

[pug_ham 245 3 Cars]

Which earth lead would be the problem? I was at my garage tonight when the rain came down so drove the car back, it drove normally but the oil pressure was above max...

The main one from the gearbox stud was to blame last time I remember seeing a car with similar indication problems.

 

Graham.

[Masekwm 2]

Popped the car back today and noticed how dirty that earth is, I shall clean it up over this week and hopefully solve the problem. I need to get this fixed to put a years ticket on it and move it on.