Ambient temp gauge

[JonB]

Sounds like removing the dashboard will entail an engine out job so that the capillary tube can be taken out with as little disturbance as possible. Nasty!

[DavidLB]

Hi A few years ago speedy cables did my instruments but they would not repair the ambient gauge, they cleaned the face but would do nothing else, something to do with the gas in the capillary

[prezoom]

An engine out job is hardly a nasty job, if one is well equipped, and only takes a few hours. The P2 engine is out right now to swap out the mid-close transmission for a close ratio. Plus, in my case, there is no need to remove the engine to R&R the gauge. The dash is another matter.

In looking at the caiguage site, their electronic ambient temperature gauge, it is very close to the one in the car, and has the red/green highlights. It may be far easier just to order that gauge. Thanks for information.

[JonB]

An engine out job is hardly a nasty job, if one is well equipped, and only takes a few hours.

That's reassuring, prezoom, thanks! I need it out anyway because it's leaking oil, and so is the gearbox. So I will need to plan this to coincide with swapping the dash out and replacing all the grommets.

(By the way, I meant it was nasty to have to pull the engine to get the ATG out safely.)

[Grizzly]

Last one i did i contacted the guy who was doing the gauge recon and asked if he needed the Capillary, the reply was No so i cut it near the gauge removing it in sections then sent just the gauge off for a nice new Capillary. Refitting i just routed it slightly differently.

[mcclelland]

lot-gauge-2.png (165.72 KiB) Viewed 815 times

lot-gauge-1.jpg (47.59 KiB) Viewed 815 times

This is the ambient temp. gauge from 'Caerbont Automotive Instruments Ltd'. They have quoted a price of ?162 for the gauge which includes vat and delivery. Tel: +44(0)1639 732200 They are based in Swansea.
The gauge comes with a Lotus grey face made for the Plus 2 application and has white numerals etc. (Pic 2 shows artwork for the gauge face).
This is just for your information...I have no affiliation to the above.

[bob_rich]

Hi All

I managed to repair my Ambient temperature gauge. I had to make up a new capillary tube and bulb and then developed a method of filling it with suitable fluid. After some test I found that butane/propane mix camping gaz had a useable temperature / vapour pressure characteristic and after making up a bulb and a capillary and new bulb filled it installed it in the car and it has been working OK for the last 3 years

I wrote up and article for Club Lotus magazine and have attached an copy (my original draft) of it here

It is a bit of a fiddle but was an interesting project.

hope this helps and seasons greetings

Bob

[JonB]

Hi Bob

Maybe you could offer a repair service. You have created a nice rig to fill the gauges there - be a shame to only use it once.

(By the way, mine is working now, but will it carry on working after I change the dashboard?)

Another thought - Would it be in order to protect the capillary tube with a soft setting paint like Hammerite "Smoothrite", or would this impair the function of the thing?

[billwill]

The tube is usually copper or Kunifer and doesn't need corrosion protection. I doubt if anything outside the tube (except heat) would affect the readings. It's basically a pressure gauge reading the vapour pressure of the active fluid,

Bob_rich, in your document, you mention 'usual failure' by corrosion of the capillary tube, in my experience that does not happen, most faults of these capillary systems seem to be due to the tube flexing, vibrating and then cracks due to fatigue failure, letting the liquid/gas out .

[bob_rich]

Hi John

I have not looked at a repair service though I might look at the odd one if the gauge itself was in not too bad nick.
As you saw in my note it really only works from around -4 to +30, though it is useful in summer to correlate the air and coolant temp on hot days.

Regarding the capillary tube usually these rust through, usually only a pin hole.but that is enough, and the working fluid is then lost. painting the capillary tube should not cause any issues providing the paint is not so thick that it makes bending the capillary difficult.

On purchase the capillary and bulb was all missing from my car so I installed the temp sensing bulb on the left hand floor out of the direct airflow close to the vacuum reservoir that operates the head lamp pods

I would be interested to know where the original position was

you should, with care be able to remove the gauge and capillary from the dash without the need to remove the dash

Best of luck

Bob

[bob_rich]

Hi again

I had not seen Bills post when I added my second post. Certainly it won't be rust if the tubes are copper or a copper alloy ! With the ambient air gauge I would not expect vibration to be a problem as I assumed the sensor would be mounted on the body and not the engine so it could be cleated down to prevent any vibration and or movement problems. Vibration and movement would be more of an issue with water or oil temperature gauges as these are connected to the engine.

I still think that you should be able to get the ambient air gauge out without removing the dash board. I fitted mine after the dashboard had been fitted to the car so removal should be a reversal of that process - - but I suppose that what all the manuals say ! Just be careful not to excessively bend the capillary and disconnect the battery so the capillary does not run the risk of shorting out some of the electrics.

best of luck

Bob

[JonB]

Thanks Bob

I'm a long way off doing the dashboard! My sensor bulb is located in the nose cone, dead centre underneath the grille. Have no reason to suspect this isn't original given the length if the capillary tube. It's tied down to the body and passes into the nose cone under the carburettors.

Cheers
JonB