Oil Pressure Drops

[tvr5000]

Hi,
I've a 5ltr that runs at around 35PSI on the Oil guage at all times, but tonight it dropped to below zero. When I pulled over to the side of the road the car was ticking over and it raised to above 30 again. But when its revved over 2000 the pressure drops down again.
There's no loss of oil, power or any additional noise, so I'm thinking its a sender problem
Anybody got any ideas.
Cheers
Mick

[wongthecorrupter]

dodgy oil pressure sender

[haircutmike]

I have replaced the sender twice with similar problems.

In the end I replaced the lot with a mechanical system .

[Chimpafrolic]

haircutmike said:

I have replaced the sender twice with similar problems.

In the end I replaced the lot with a mechanical system .

Hi Mike, what readings are you getting with the mechanical system?

Str8six told me if you plumb a decent gauge into one of the galleries on an RV8 the true oil pressure is significantly higher than the 35lbs figure we see on the TVR guage.

Interested to know if that matches your experience?

Thanks, Dave.

[haircutmike]

Chimpafrolic said:

haircutmike said:

I have replaced the sender twice with similar problems.

In the end I replaced the lot with a mechanical system .

Hi Mike, what readings are you getting with the mechanical system?

Str8six told me if you plumb a decent gauge into one of the galleries on an RV8 the true oil pressure is significantly higher than the 35lbs figure we see on the TVR guage.

Interested to know if that matches your experience?

Thanks, Dave.

Hi Dave.

From cold start up it registers 50 psi at idle dropping to about 40 psi when warm, (haven't had it at "thrashing" hot yet as it hasn't been in long and the weathers crap!).
Registers about 55-60 at speed when warm.

It also has a usefull oil temperature section that registers temp at approx. the same as the water temperature, (again, no chance to give it the usual T/D caning!).

Hope this helps.

[Chimpafrolic]

haircutmike said:

Chimpafrolic said:

haircutmike said:

I have replaced the sender twice with similar problems.

In the end I replaced the lot with a mechanical system .

Hi Mike, what readings are you getting with the mechanical system?

Str8six told me if you plumb a decent gauge into one of the galleries on an RV8 the true oil pressure is significantly higher than the 35lbs figure we see on the TVR guage.

Interested to know if that matches your experience?

Thanks, Dave.

Hi Dave.

From cold start up it registers 50 psi at idle dropping to about 40 psi when warm, (haven't had it at "thrashing" hot yet as it hasn't been in long and the weathers crap!).
Registers about 55-60 at speed when warm.

It also has a usefull oil temperature section that registers temp at approx. the same as the water temperature, (again, no chance to give it the usual T/D caning!).

Hope this helps.

Yes it does help Mike, thanks.

Your figures sound perfect to me, much more realistic than the TVR gauge quoted 35lbs, it supports what I expected and have been told.

Your system should certainly be way more accurate and reliable than the standard setup.

From what I can see the standard gauge is both badly calibrated to, and significantly hindered by, the very crude sender unit.

I suspect all the standard setup is telling us is whats going on inside the sender reservoir not whats being delivered to the mains & big ends.

With such a small amount of oil in the sender reservoir no wonder we see such fluctuation when the oil changes temperature.

Where did you plumb your mechanical setup to?

I assume there a tap-off plug in the block that goes directly into one of the main oil galleries?

Perhaps you would be kind enough to share some snaps?

Edited by Chimpafrolic on Tuesday 11th January 09:05