Oil Temperature gauge

[mike150]

I've got it in my head that I'd like to know my oil temperature as I'm paranoid about cold oil!

My current, cheapest, easiest idea is but a small digital battery powered gauge from Ebay for £1 (I kid you not) and stick it to the bottom of the dry sump tank with alloy tape and use heat transfer paste to get a good signal.

https://www.ebay.co.uk/itm/LCD-DIGITAL-FISH-AQUARIUM-WATER-TANK-THERMOMETER-TEMPERATURE-50-C-TO-110-C-NEW/292163797135?hash=item440651c08f:g:9i0AAOSwjvJZQzyk:rk:48:pf:0

I think the best way would be to replace the oil pressure gauge with a dual pressure and temp display from Racetech or Spa but I'm not keen on mods like that, I just want to know if my oil is warm enough!

How have others done this easily?

Thanks

[Jonathan Kay]

Private Message sent.

Jonathan

[John Vine]

What model and year of 7 are we discussing?

A common solution is to fit a temp sender (same as the water temp sender) to the dry sump tank (or, for wet-sump cars, to the sump).  With luck, you already have a take-off union or sender.  Then run the wire to one side of an indicator-style switch, reroute the existing water temp wire to the other side, and a new wire from the central common terminal to the temp gauge.  You can then toggle easily between oil and water temps, and you keep the original gauge.

ETA: I've just spotted your profile photo.   Is it the case that a 620S doesn't already have a means of displaying oil temps?

JV

[ScottR400D]

I did exactly what JV outlines. Cheap, very easy and perfectly functional. 

[nickh7]

Yep did the same , switch position, oil up water down . If you have an Apollo Tank the sender is already fitted 

[John Vine]

... oil up water down.

I placed the switch in between the water temp gauge and the oil pressure gauge.  So, toggle left for water, right for oil.  Easier for an old duffer to remember.

JV

[ScottR400D]

Exactly what I did John! For exactly the same reason!!

[aerobod - near CYYC]

I also did the same as John, but used a black rocker switch instead of a toggle switch: https://www.active123.com/3016155-Rectangular-Bezel-Round-Rocker-Switch-SPDT-ONON-Black-Prodview.html

[mike150]

I take it I may just need this then.....................

https://caterhamparts.co.uk/senders/17-temperature-sender-96-onwards.html?search_query=temperature+sender&results=77

And a switch.........................

https://caterhamparts.co.uk/switches/235-switch-indicator-2002-onwards.html?search_query=indicator+switch&results=124

 

 

[aerobod - near CYYC]

You may even have the sensor in the dry sump oil tank already, my tank on the R400 had it fitted and also had a wire connected, but not connected to any instrument. I couldn’t find the end in the loom near the instruments, so just ran a new wire from the oil temperature sender to the switch on the dash, then made a pigtail to the switch which connected to the temperature gauge and a pigtail from the switch to the existing water temperature sender, so that none of the existing wiring had to be modified.

[7 wonders of the world]

If your putting a oil temp sender in a dry sump set up it needs to be located in the sump trough, you can drill and tap the plate that retains the finger filter this way you can monitor peak oil temps too.

[tomwood]

Yup same mod that I did as well. Works really well. Just make sure you drill the hole for the switch in the right place, it will annoy you for ever more if it’s not exactly in the middle between the two existing gauges.

Tom

[tomwood]

If you fancy doing the same, there’s more on now to do it in this thread. Final post has a wiring diagram that I put together which may prove useful:

https://www.lotus7.club/forum/techtalk/water-oil-temp-gauge-switch-mod-advice-needed?page=1

Tom

[John Vine]

Yes, although you could also use an ON-ON dip/main switch instead of an ON-OFF-ON indicator switch.

There seem to be two schools of thought on this:

1. Those that favour an ON-OFF-ON indicator-style switch, on the grounds that it introduces a clean break between the two sender signals
2. Those that opt for an ON-ON dip-style switch

My current set-up is in fact option 2, although the common solution I described in post #3 shows option 1.  I think either method will work just fine.

JV

[john milner]

I fitted a Caterham water temperature sensor to the oil filter housing (K Series) and then used an on/off indicator switch using the long disconnected oil pressure gauge wiring. The switch is between the bottom of the water temp and oil pressure gauges. Switch left for water and right for oil so fairly intuitive.

It's a gadget that I don't really need but is reassuring as I now know it takes about 20 minutes for the oil to warm up and only a motorway blast on a hot day gets the temperature towards high.

[mike150]

So I ended up buying a small digital temperature gauge from Ebay that reads to 110Deg, stuck it on the dash just above the oil pressure gauge and ran the lead through the firewall and taped it onto the back side of the dry sump tank with aluminum insulation tape. It seems to read well as I tried the probe in the oil return flow by taking the lid off and checking it for accuracy by running the car right up to full temperature and the oil eventually got up to 85deg.

£1.21.................I kid you not! I bought 2, should have bought more maybe!

https://www.ebay.co.uk/itm/NEW-BLACK-AQUARIUM-TEMPERATURE-GAUGE-LCD-DIGITAL-THERMOMETER-FOR-FISH-TANK-SMART/163272111685?hash=item2603c6b645:m:mL6UzFBu7qApMXE83wGHq6A:rk:7:pf:0

[John Vine]

That's neat!  Did you manage to calibrate it (at 100C, at least) by dunking in boiling water?

JV

[mike150]

No, never thought of testing it boiling water! Might try it. I wanted it as a guide of the oil temperature as I'm paranoid about revving an engine on oil that's not at least 70deg and especially with the erratic cooling that's so ambient temperature sensitive on a 620.