Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Fluttering oil pressure guage

My oil pressure gauge in my Tr4 engined +4 is fluttering since I changed oil and filter.
Seems to read accurately .Reads 50+ pressure (brand new oil)
Moves up and down with revs etc.

Fluttering gets faster when warm and with higher revs.
To the point where you can hardly see the needle.

Engine runs fine, only done about 1200miles since rebuild.
Do see instrument cluster is wet around but no leak at Union.
So inclined to think it’s not a coincidence.

As engine runs fine I’m presuming it’s instrument, however paranoid of course.
Removed pressure regulator and all clean and good.
Swapped filter basically still same.
20/50w Oil near max 5.2ltrs

What’s next?

Could this be some air trapped in the pipe to the gauge? Maybe loosen off the union at the back of the gauge, place some rags around to catch oil and run the engine until oil is running out of the pipe then nip it back up whilst under pressure.

If the above doesn't clear it, You could try getting a cheap and cheerful oil pressure gauge (or borrow one from a parts-hoarder pal) temporarily connect it up and see if that flutters ... if not you'll likely need a new oil pressure gauge ... if it does it's in the motor.

K

Sounds like the issue is in the guage - if you're getting signs of fluid leakage?

Not entirely sure how these work internally, but it sounds like the pressure is building, then the oil is escaping through a pin hole. dropping the pressure, which is then building again, hence the fluctuation.

All good suggestions.
The one regards leak causing pressure peaks sounds good too.

Do these gauges need bleeding? I would have thought any air would compress just the same?

Air in the oil gauge line shouldn't cause the issue, indeed if anything it would dampen fluctuations. TBM's suggestion that curved copper coil within gauge has pinprick leak sounds feasible if oil is seen around gauge. Substitution, if only temporary should prove.

Sounds good.
So can these gauges be fixed?
Maybe I can solder a leak?

Asuming of construction I'm familiar with, the hollow copper coil flexes towards straight with pressure within, the movement linked mechanically to gauge pointer. Given flexing a soldered repair would IMHO offer only temporary cure. Example below.

I have opened up the instrument will now remove and see