Gt3 oil pressure gauge reading

[shaunw]

Hi all, the oil pressure gauge on the Esprit GT3 I viewed today reads extremely low, nearly off the gauge when hot. I find it hard to believe  the reading is correct as the engine is very strong, quiet, burns no oil and has low mileage. The oil light goes out immediately on start up. Im obviously not expecting anyone  to diagnose an issue like this without even seeing the car but my question is, has anyone had a similar issue and found the gauge or sender to be faulty?

[shaunw]

Having finally found the search function🙄 I've  had a look. It seems that quite a few have had the same issue and found it to be due to the sender. Doesn't necessarily mean that's the issue in this case but that's quite reassuring!

[Sparky]

Yeah, not uncommon.  If you can get hold of a tester, you can attach it to the block in place of the sender and get a true measure.  They're very cheap and available on eBay/Amazon.

[drdoom]

. . . . or add a tee fitting at the block and run a line out to a nearby mechanical gauge for comparison, there anytime you have doubts.

[shaunw]

Thanks guys 👍

[Sparky]

Thus sender is a big beast; you'd have trouble fitting to a T-piece unless you run a second line and mount it remotely.  Which, coincidentally, is similar to the GT3 I'm currently working on!

[Escape]

Just to add, the oil pressure warning light doesn't come on below 1600rpm, so as not to avoid people worrying about it...

[tomcattom]

12 hours ago, Sparky said:

Thus sender is a big beast; you'd have trouble fitting to a T-piece unless you run a second line and mount it remotely.  Which, coincidentally, is similar to the GT3 I'm currently working on!

I don't know if the GT3 is different, but I had to fit a T-piece on my S4s so I could add the deleted oil temperature gauge back to mine.

This is it with the incorrect taller pressure sensor that was originally fitted to the car by the previous owner. It's snug, but it does fit.

There is much more clearance with the correct sensor can fitted however.

[fjmuurling]

Hi Tom, @tomcattom

You could have used the already present oil temp sensor on the left side of the oil gallery cover just under the turbo oil feed line, with the benefit of it sitting in the oil flow. 

[tomcattom]

11 minutes ago, fjmuurling said:

Hi Tom, @tomcattom

You could have used the already present oil temp sensor on the left side of the oil gallery cover just under the turbo oil feed line, with the benefit of it sitting in the oil flow. 

That temperature sensor isn't present from the factory on the S4s @fjmuurling. What you can see in the photo is the end arrangement I created so I could install the temperature gauge in my car.

The CAI instruments in the S4s have a separate low pressure switch and sensor, unlike the earlier S4 which is a combined unit. Lotus dropped the oil temperature sensor (and gauge) on the S4s and replaced it with the separate low pressure switch (a backwards step if you ask me).

To reinstate the oil temperature sensor, I installed that T-piece you can see there so I could move the low oil pressure switch to make way for the oil temperature sensor to go where it would normally be located on the S4.

[CarBuff]

TOPIC DRIFT ALERT!

 

The original query was regards the oil pressure sender. 🙄

 

An 'open' circuit will cause the dash gauge to 'peg' towards the high end. So, a high resistance will cause higher readings than actual. Or, 'twitchy' readings.

 Our dash gauge has always been a bit spotty due to loose fitting spade connectors (a 'tradition' with Lotus wiring, even to this day). What really calmed ours down was re-crimping and soldering the right-angle wiring connectors.  (Easier said than done with the limited access)

 

Good Luck...

 

PS We installed our mechanical oil pressure test gauge right at the turbocharger.  More room there. You can see the twitch in this video.

 

 

Edited May 9, 2022 by CarBuff

[EXCEL V8]

Never mind this oil pressure stuff 😉.  An Esprit Shaun??  Spill 😁

Pete

[Roy Lewington]

Oil Temp.   I fitted a sump plug from Matt Lewis Racing (Dorking) which takes  a temp. probe.  Probe thread is 1/8th npt although I think an M10x1.0 is supposed to also fit.  Plenty of gauges online, I fitted a KOSO unit under the dash which is easily removable if a future owner didn't like it. Works fine.     Roy.