Oil Pressure Loss!

[DavidL]

Yesterday I managed to start my Gold after a gap of about a year and a half.

The oil pressure light remained on. The last time the car ran, I had no oil pressure problems that I'm aware of...

I removed and inspected the pressure relief valve. I looks a bit scuffed on the conical part of the plunger, so I've ordered a new one, and a new oil pressure switch, just in case that's faulty. However, I noticed on MiniSpares's description of the new plunger the recommendation that a new plunger should be "lightly ground in" as inlet and exhaust valves are. Has anyone fitted a new relief valve and had to do this?

Also, given that the engine's been standing unstarted for such a long period of time, are there other possible reasons for the apparent loss of oil pressure that I have? The old oil was drained and replaced with new 20W/50 just a few weeks ago. I should add that I probably let the engine run for about a minute or thereabouts, just in case it needed time to build up pressure. I do hope this wasn't a big mistake...

As always, thanks in advance for any and all assistance.

[kelvink]

Personally I tend to turn the car over a few times with the plugs out to get things flowing without actually running it. Less chance of excessive wear on a dry engine and gives plenty time for oil to get pumped around before the engine is fired up. Also easier on a battery too.

[DavidL]

I did that too.

I'd drained the tank because the petrol had been standing so long that I didn't want to have any uncertainty about fuel that'd gone off. I was amazed at just how long it took cranking the engine over before fuel actually made it all the way to the carb, despite the car sitting slightly nose down. In fact, the battery needed a recharge before the fuel got to the carb...

Eventually I removed all the plugs and continued to crank it until the petrol appeared. (Interestingly, 3 plugs are the same type - no. 2 cylinder has one of a different type. Hmm.) Once the carb was full, I put them back in, charged the battery up again, and it started almost instantly and ran. I'm hoping that at least some oil was circulating while I was doing all that, because I don't yet have a spare engine.

[Stuart]

I had a right faff getting oil pressure on a stood engine, I even ended up pouring oil into the pressure relief valve, I got there eventually.

[DavidL]

I had a right faff getting oil pressure on a stood engine, I even ended up pouring oil into the pressure relief valve, I got there eventually.

Glad it's not just me. Does my scenario sound familiar?

Do you remember how long it took? I might try the "squirt oil into the pressure relief valve" technique, sounds like it would be worth a try.

[max midas]

Also, when you changed the oil recently, did you change the filter? The filter must be primed when re-fitting, ie filled to the brim before being screwed back on its bracket.
And yes, I'd drown the pressure relief valve in oil.

[DavidL]

Also, when you changed the oil recently, did you change the filter? The filter must be primed when re-fitting, ie filled to the brim before being screwed back on its bracket.
And yes, I'd drown the pressure relief valve in oil.

Oh yes, new filter as well, and it was filled as well as I could. I'll try slathering the old relief valve in oil tomorrow and refitting it.

I've noticed that MiniSpares do two different oil pressure switches, one that switches at 7-10PSI and another which switches at about 20-30PSI (and they have an adjustable one too, but...). I'm toying with the idea of fitting one of each on a T piece which would give a two stage oil pressure warning. Am i just being peculiar?

[Hans Efde]

Also, when you changed the oil recently, did you change the filter? The filter must be primed when re-fitting, ie filled to the brim before being screwed back on its bracket.
And yes, I'd drown the pressure relief valve in oil.

Oh yes, new filter as well, and it was filled as well as I could. I'll try slathering the old relief valve in oil tomorrow and refitting it.

I've noticed that MiniSpares do two different oil pressure switches, one that switches at 7-10PSI and another which switches at about 20-30PSI (and they have an adjustable one too, but...). I'm toying with the idea of fitting one of each on a T piece which would give a two stage oil pressure warning. Am i just being peculiar?

That's not a good idea. It will freak you out anytime the engine idles, because it will get below 30psi. If you want to know the oil pressure, install a gauge. This will warn you way before the oil press light comes one and also indicates the health of the engine. I have a simple mechanical gauge, it was there when I bought the car. I simplified the connection, but basically you put a "T" between the block and the pressure switch. On this "T" a very small oil line is fitted that runs to the gauge. It is non electrical so always will work (even the chaps that race prefer this over the electrical gauge), just hook up the instrument lighting. It is very educational and gives info about oil pressure in relation to the sort of oil you use and the condition of the engine. I can see a huge difference now between my old and new block (old oil pump was heavily grooved) and changing from 15W50 to 20W50 oil.

[DavidL]

Also, when you changed the oil recently, did you change the filter? The filter must be primed when re-fitting, ie filled to the brim before being screwed back on its bracket.
And yes, I'd drown the pressure relief valve in oil.

Oh yes, new filter as well, and it was filled as well as I could. I'll try slathering the old relief valve in oil tomorrow and refitting it.

I've noticed that MiniSpares do two different oil pressure switches, one that switches at 7-10PSI and another which switches at about 20-30PSI (and they have an adjustable one too, but...). I'm toying with the idea of fitting one of each on a T piece which would give a two stage oil pressure warning. Am i just being peculiar?

That's not a good idea. It will freak you out anytime the engine idles, because it will get below 30psi. If you want to know the oil pressure, install a gauge. This will warn you way before the oil press light comes one and also indicates the health of the engine. I have a simple mechanical gauge, it was there when I bought the car. I simplified the connection, but basically you put a "T" between the block and the pressure switch. On this "T" a very small oil line is fitted that runs to the gauge. It is non electrical so always will work (even the chaps that race prefer this over the electrical gauge), just hook up the instrument lighting. It is very educational and gives info about oil pressure in relation to the sort of oil you use and the condition of the engine. I can see a huge difference now between my old and new block (old oil pump was heavily grooved) and changing from 15W50 to 20W50 oil.

I realise that - both lights on with ignition off, both off at cold idle and normal driving, one light on at hot idle was what I'd expect. I wouldn't sell a car with two oil pressure lights, but I'd know what to expect.

I accept that I'd be better fitting a gauge though, if I was worried about my oil pressure at all. Currently I just want to get some oil pressure...

[manifold]

I agree with Hans.

Get a capillary oil gauge with a T Piece. I wouldn't run an A series engine without one. Don't use the electric ones they are shit and fail frequently.