Low oil pressure and coolant stuck in expansion tank

[Timja]

This may be 2 issues but posting together in case they could be connected.

1) Low oil pressure. I’ve noticed recently that the oil pressure guage drops below zero after engine has warmed up and it’s being driven. When 1st started it is at about 35psi which from memory seems fairly normal but when it’s warmed up and being driven it drops well below zero.

It drops when accelerating. The oil level is at max on dip stick.

Does anyone else’s do this or any ideas on issues?



2) I have done a few track days and noticed each time that there was some coolant leaking from expansion tank. Assumed it had just got too hot or was overfilled but when let to cool, the expansion tank stays full and it doesn’t go back into the system. I bled the system opening bolt on top of radiator then filling swirl pot to top (transferring from expansion tank). Having driven on the road it doesn’t seem to get the same issue just after a track day where I was fairly sympathetic and temperatures never went above 80 on dial, but obviously was driven harder than on the road.

Any ideas?

Thanks

[QBee]

May not be the answer, but.....

1. Oil pressure going to zero. I came away from a track day where all was well all day, headed off down the A11 and noticed that I had no oil pressure unless I accelerated.
Stopped immediately and phoned my TVR expert ( who was still at the track day, about to leave). He came and had a look and diagnosed a loose connector on the oil pressure sender. On my later Chimaera this is at the bottom of the front of the engine, down at chassis level. I adjusted it with a pair of pliers and it has been fine ever since.

2. Coolant levels. Heat on the track day is forcing the coolant back into the (normally 1/3rd full) swirl pot and, if that gets full, forcing a little out of the pressure cap. The level in the swirl pot is compensating and keeping the expansion tank full.
You need to learn how full your swirl pot likes to be and monitor that level - on my car it is somewhere near 1/3 full. I keep it to that level. If I fill it to 2/3rds, the car promptly spits the excess out the first time I drive it again. The cooling system has several litres of coolant in it.
A little coolant lost from the system can spread a fair way across the tarmac under the car and look to be more than it is, a bit like half a cup of coffee spilt on your desk

[WOO5IE]

If the oil pressure light is not coming then it’s more than likely the sender or connector as suggested by Queen. Easy fix

[Timja]

Oil pressure sorted. Was a loose connector as suggested, thanks.

Will have to monitor what the water does under normal driving conditions.

[QBee]

You could ask that well known engineering genius, Dr Jeremy Clarkson, about the fluid loss.
In my head I can hear him commenting that a little seepage is perfectly normal and to be expected when driving a TVR on a track, and then smirking at the camera.

[PabloGee]

I also noticed the oil pressure sitting quite low when the engine was cold yesterday, but it rose to around 35psi as I was driving and stayed there.
Good tip though on the connector - I will also give it a look whilst I'm footling about with a sheared bolt on the PAS pump housing!

[QBee]

I suspect all our gauges read low.
Learn where yours normally sits and check the oil level regularly