I need some advice! When I start my engine, the oil pressure climbs to 65 psi. After 40 seconds or so, it drops to 20 psi. The engine has just been rebuilt with new pistons for bearings etc. l presently have the oil filter mounting block off to check the pressure relief valve. However, it looks ok. Any ideas or advice will be greatly appreciated! Regards, phil G
I’d want to verify those readings with a mechanical gauge.
I suspect your real pressure is ok and it is likely the sender but you can only verify this with plumbing in a mechanical gauge as John suggests.
I calibrated my sender by taking it out, connecting to the gauge, pressuring it with compressed air on my bench at 40 psi and then calibrating it both for 40 psi and for zero psi. If you calibrate the gauge and it is still flakey, it is usually the sender that is at fault.
Dennis 69 OTS
I ordered a new sender after my original was showing variable readings. Eventually my new sender showed lots of wonky readings on the Oil Leaks (tours) so I ordered a Smiths Mechanical Gauge from Merlin Motorsport in the UK and installed it in the dash place of the old electrical gauge. So far it appears far more consistent that the others.
–Drew
Is that the 100 psi gauge?
I ordered a repro Smiths dual-gauge from Merlin, and BOTH the oil and water side were flakey. I took it to my local gauge guy, and he spent 3 hours getting it working properly. He described the internals as “cheesy replicas of an original, 60’s Smiths gauge.”
From now on, I’m only going to use restored original gauges. I understand there’s a mechanical, Lotus Europa oil pressure gauge that looks perfect in an E-type after you switch the bezels.
If there’s a list forming for “Flaky Merlin gauge owners” add me.