Urgent Help!! Oil pressure low.

[pullingpower]

The car is 3 weeks and 450 miles since engine rebuild. In the last 48 hours the pressure gauge is very irratic. On starting from cold, the needle barely moves and stays below 0! When warm, not much change. When I pull away and the engine is 'worked', the pressure comes upto normal (30-60). If I lift off or hold neutral accelerator pressure, it drops low again, sometimes below 0 again. When sat in traffic it can fluctuate from 0-15.
The dash lights all light up when I turn the ignition and no warning lights are coming on when driving to suggest no oil pressure. The oil level is full on the dipstick and the car is sounding and driving perfectly.
What is going on??? Is it going to go bang or is it just instrumentation/sender problem?

[rnd]

I had that problem with my chim, when ticking over it was reading very low pressure and also very irriatic. Changed the sensor and it cured the problem but I am sure you are worried as it has just been rebuilt. Hope ti is not something serious.

[GreenV8S]

Make sure the oil pressure warning light works before you go any further. And make sure you aren't confusing it with the no-charge warning light. Having done that, if the oil pressure warning light stays off then you do have some pressure so might feel brave enough to keep the engine running despite what the gauge says. If the gauge shows the pressure jumping up and down, or shows zero when the warning light shows you still have oil pressure, then I would suspect a duf sender or damaged wiring out by the sender. If the engine's been worked on recently then it would have been very easy to smack the sender or damage the wiring.

[pullingpower]

Thanks for quick replies. I'll give the sender a wigle and check the connection. I have read that the spade connector can come loose sometimes.
Just to confirm, where on the dash is the oil pressure warning light?

[david beer]

After my Taraka work, when accelerating, the oil pressure would drop to Zero. It was just the pressure sender spade connector having being disturbed, quick squeeze with pliers, all back to normal.

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david beer said:

After my Taraka work, when accelerating, the oil pressure would drop to Zero. It was just the pressure sender spade connector having being disturbed, quick squeeze with pliers, all back to normal.

Yep I had this too, After painting the chassis, my oil pressure gauge was erratic, turns out I had knocked the wire partly off when wax-oiling the chassis!

[pullingpower]

Ok, so driven car over weekend without engine blowing up and no warning lights. As before the oil pressure is normal when engine under strain but drops away to < 10 or even <0 when I list off. On the motorway it sat at normal range while foot on the gas. It is just very difficult to relax when lifting off at 70mph and seeing the oil presure go below 0!!! Interestingly when idling in traffic, revving only makes a small increase.
I have looked on TVR gear and they appear to have some new oil pressure senders available. They have 2 but one has (PAL) after it. What does this mean and which one should I get?

[Nuggs]

Sounds very much like the problem mine had last week. Started by 'losing' pressure when lifting off, then pressure went below zero and then went over 90psi.

Asd the engine hadn't lunched itself after a few miles on less than zero, I figured it was new sensor time. I ordered mine from Leven, had it fitted on Saturday and all is now fine