Technical Low Oil Pressure/ Ominous Tappety Noise

[guyschofield]

Hello!

I've got a 78 lido which seems to have abnormally low oil pressure: when hot its less than 10 psi: pretty near the bottom of the gauge. I've heard that the pressure gauges on these cars are know to be a bit unreliable and not to trust them. Is this true? The car doesn't use any oil and there's no buggered crankshaft noises or other bottom end engine knocking sounds so it seems odd: is there any classic reason that these cars run poor oil pressure?

Also it's gradually developed what first sounded like a very noisy tappet when its idling: sounds like someone tapping a small spanner on the top of the engine. When you give it some throttle it goes away, which suggests (unless I'm mistaken) that there's a little end on its way out. Is this common or likely? Does anyone know of anything it might be that won't involve taking the engine out?

Lastly, is there likely to be any connection between the two problems?

Thanks very much in advance!
Cheers,
Guy

 

[jimbro1000]

To answer your last question first - yes. Odds are the oil pressure is borderline at idle resulting in a lack of lubrication. This means rapid wear of the cam and shims so worth getting sorted asap!

Chances are the oil pump itself is a bit worn out...

 

[guyschofield]

Thanks Jimbro: that would be lovely if it turns out to be the problem: much nicer than digging up the engine!

Cheers,
Guy