Job I Wish I'd Not Started.

[John042]

350i pressure gauge slow to read. No problem, identify the gauge ordered a new sender job done. Trouble is it's as slow if not slower than the old one. The old one got toasted on removal in fact the connection disintegrated. Pressure is also reading lower than originally. At present 18-20 psi at 1000rpm and 40 ish at 2000 rpm. Oil light goes out on start, engine as done 82k with no noises of mechanical problems. I've been assured by the supplier, Rac***t that I have the correct sender for my gauge. Cause for concern or live with it? It would give me a warm feeling if I could some how fool the gauge to read higher? Thanks for any thoughts or reassurance. J C.

[mrzigazaga]

Hi John.


Thats about right for oil pressure...what grade oil is in it?

It should also flick up a bit when revved...

[John042]

Hi Mark, yes it eventually crawls up to 40 ish. Using good old 20w50 at the moment. Just pi** off after all the effort especially when I sheared the brass adapter and had to purchase another for what appears no gain over the original.

[mrzigazaga]

The RV8 doesnt have high oil pressure, its not good for it...yours sounds on the money..it will be different pressures at different rpm's...just drive it mate...

[John042]

Thanks Mark, I seem to have read somewhere that the V8's thrive on oil flow rather than pressure? It's the slow response of the gauge that seemed suspect, although shorting the supply connection sees the gauge rapidly indicating full scale. Certainly the new sender has not improved matters. We'll see how it behaves once the drive shaft U/J's are replaced. Cheers Mark.

[mrzigazaga]

Just remember that the gauge is not a reliable accurate representation of the true oil pressure...its better than just the light coming on ...

[John042]

Cheers Mark. I seem to remember some previous posts of members fitting additional direct reading pressure gauges?

[colin mee]

I changed mine for the pipe type. A lot more reliable.

[John042]

Thanks Collin. Did you use the same pressure connection and get a matching gauge?

[colin mee]

Used a durite one.it's was the only black face I could find

[colin mee]

I think it came with one. John

[John042]

Thanks Collin. Is it a direct reading gauge through a capillary pipe?

[colin mee]

It was like this one on ebay 122208458111 I think

[John042]

Thanks Collin. A friend has just given me a collection of senders so may play with them to see the results. Pity I can get a direct reading gauge to match the vertical reading ones. Cheers J C.

[mrzigazaga]

Hi John

This might help...I doubt there's anything wrong with your oil pressure!!...just drive the damn thing....

https://www.roversd1.nl/sd1web/oil.html

[ed_crouch]

The TVR sender and gauge is very very variable in its accuracy.

I'm changing one at the moment for a Honeywell calibrated sender. Bought a new oil pressure gauge from CAI because the old one had a lot of hysteresis in it.

The trick bit is that I'll be driving the gauge not from the sender directly but from a microcontroller via PWM, so I can calibrate the gauge in the software and have it bang on.

Individual calibration is the only way with the original kit as it just isn't accurate enough to be relied upon.

Ed.

[citizen smith]

If you are having nightmares about the Oil Pressure, my advice would be to temporarily fit a Mechanical Gauge somewhere and see what's going on. Try an ex MGB gauge etc, off e,bay.

[adam quantrill]

I had scrapped an SD1 and for a while ran with the gauge and sender off that too see what was going on.
The gauge was perched on top of the 350i centre console box.

Anyway after a few weeks I figured out the original gauge was just reading a bit low, swapped back to it, and carried on to put a total of 140k on that engine.

[John042]

Thanks Mark/All. Never had such a lasy gauge. Yes once the drive shaft is back it's going to get a good thrashing. Cheers J C.

[mrzigazaga]

John042 said:

Thanks Mark/All. Never had such a lasy gauge. Yes once the drive shaft is back it's going to get a good thrashing. Cheers J C.

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