23 replies to this topic

[Tonylamb]

So I attached my workshop oil gauge to the outlet. The Oil Pressure is 65 to 70 cold. Once warmed up the oil pressure drops to around 55 at 2000 rpm but revving the engine lowers the oil pressure to 40 to 45. Revs up oil pressure down. Something not right with that. It doesn't drop below 40 psi but its very wierd.

[Tones61]

Poss sticky relief valve,take out,fine wet and dry sides,have done this before,

[Stevie W]

+1 for a sticky pressure relief valve.

[Tonylamb]

update. took the pressure relief valve out. I couldn't get the piston that is in the block on the end of the spring out. I did wind it in a bit so that the Idle pressure was around 60psi. So clearly there is good oil pressure. Then I took the car for a spin to get the oil properly hot. Go over 2500 rpm and the pressure drops from 75 to 60/65. But when the oil is really nice and hot at idle the pressure drops to 40. Blip the throttle and it instantly blips to 70 but it still drops when you rev. At 5500 rpm its around 70psi. Its just wierd to be honest.

[nicklouse]

get the valve out and clean it. if is not closing properly.

[Spider]

What type of Relief Valve are you running ?

 

It could also be an indication that there's excessive Big End Clearances.

[Tonylamb]

I'm not sure which sort it is. 1inch nut holds it in with a smaller threaded screw through the middle and a large spring. As I said I couldn't get the plunger out of the block. It is working to some degree though because when I adjusted it by a couple of turns it changed all the readings. I have a video of the pressure movements but i think its too large to put on the forum?

[imack]

I've cranked the engine and used oil pressure to remove the oil pressure relief valve plunger before now.
Remove the plugs and the oil pressure relief valve cap and spring from block (sounds like you have an adjustable one). Place a load of rag ontop of the starter motor below the relief valve and give quick flicks of the ignition key until the shuttle come out (might be a ball bearing type but these don't usually get stuck).
If your inner wing mounted starter solenoid has the starter button in the middle you can press to crank the engine it's even easier as you can see the shuttle come out- just make sure the cars not in gear and you run yourself over!

Edited by imack, 18 April 2020 - 09:05 AM.

[Tonylamb]

thanks for the idea I will give it a try. Is it possible that the vave is sticking slightly thus giving the strange reading? And what do I do when I get it out?