Funny oil pressure 350SE

[TOPTON]

Oil pressure gauge almost acts like a rev counter, sits at about 30, drops to zero then lifts up again to 30ish. Constant 2.5k revs it sits on 30lb. The low oil pressure light never comes on though. I know it works because it goes out straight away on start up. I have changed the oil and filter, taken out and cleaned the pressure relief valve. Nothing makes it any better. I have just ordered an uprated relief spring to see if that helps. Failing that, i will changed the sender unit. Running out of ideas now though!

Any ideas anyone???

[350zwelgje]

Would think of the sender unit, but it could also be an earth connection.
I trust the oil pressure light myself, when it went out after startup.

Uprating the oil pressure relief spring can have advantages, but....
But it will put more strain on the distributor shaft and gearing, which is sort of a weak spot in the V8. The V8 needs flow, and not a lot of pressure. At least I replaced my spring with a standard version, and oil pressure is just a bit more healthy showing that after plus 15 years the spring can be weakening.

Rob

[Number 7]

TOPTON said:

Oil pressure gauge almost acts like a rev counter, sits at about 30, drops to zero then lifts up again to 30ish. Constant 2.5k revs it sits on 30lb. The low oil pressure light never comes on though. I know it works because it goes out straight away on start up. I have changed the oil and filter, taken out and cleaned the pressure relief valve. Nothing makes it any better. I have just ordered an uprated relief spring to see if that helps. Failing that, i will changed the sender unit. Running out of ideas now though! Any ideas anyone???

I've found that some of the TVR gauges are so vague as to be almost useless - and my sender is also somewhat erratic. That's why I fitted a capilliary type gauge T'd into the same point as the original sender. Your pressure should be around 40 psi over 2500 rpm under load. Relief valve springs can weaken, and the oil pump cover can get scored or the gears worn, all of which will contribute to lower pressure.

7.

[swell610]

Hi

I have a 350se too. I just bought it and the oil pressure guage makes no sense - seemed to be back to front and now has pretty much given up the ghost alltogether. No oil warning light has come on - and I am assuming that the guage and warning light don't run on the same circuit (hope!). The cars going in for a full service next week anyway - will let you know what the problem was.

Guy

[TOPTON]

Fitted an uprated pressure relief spring and everything is back to spot on. Now Runs at 40-45lb at 2.5k revs. Took about 15minutes to fit, including jacking the car up. Sure I read somewhere that a garage would charge 3-4 hours work to do it! Maybe I dreamt that bit.
Anyway..total happy bunny again

[dickieandjulie]

Hi Swell

Got 350 SE no. 9 myself, which one are you? Welcome to the club

[gsx600]

My oil pressure guage was like that, so I tee'd in to the fitting and added a capilary guage which proved the pressure to be correct.
on further investigation about a year later I went to check the area for something else and noticed the connector was looking a bit dodgy on the pressure sender. Crimped on a new connector and oil guage came back to life and has behaved ever since then. Even took the capillery one off ( I think Rodger took a picture of where it was on my bonnet )