Lotus Elan and Lotus Elan Plus 2 Forums

Hi all.
I am struggling to get the temperature sender to seal against the adapter in the head. I need to get one or some of the copper washers that seal this joint. Does anyone know where to get these? I've tried Sue Miller and speedy cables so far. Speedy cables can get them but have to buy them in and machine them = may take a while. Failing that does anyone know the exact dimensions of this so I could maybe find one from a general supplier.
Thanks. Keith.

Is this the sensor which screws into the thermostat housing on the head? I thought it was a tapered pipe thread which you seal with some ptfe tape on the threads? No doubt someone who knows will be along who can confirm or refute this....

Did it have a washer. Both of mine did not, but sealed. Until I changed one of the senders, which had a different male thread, vs the female. I drilled out a smaller copper washer, and it seems to be holding. But I have only put a few heat cycles through the engine.

Its the copper sealing washer that goes between the temperature sender bulb and the adapter which then screws into the water jacket in the head (thermostat housing). It is shown here on this thread: https://lotuselan.net/forums/viewtopic.php?f=19&t=43728
I think I have identified the size now even though I don't have one to measure (as it is mangled beyond repair). It is 1/2" ID and 9/16" OD thus 1/16" thickness.
I'll keep searching.
Thanks.

Mine is different.....the mating faces of the bulb flange and the adaptor in the head are both tapered and form a compression joint ..... no washer is required. I thought that's how they all are ?
The sender shown in your link is an oil temperature gauge sender which may differ.

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Edit:- Well it seems there are two types of bulb used, one with taper seat and one without. From the Smiths website ....

Bulb Types
Dual gauges with a temperature scale have an ether filled bulb fitted at the end of armoured capilliary tubing there are two main types (pictured on the left) A2 and K, these are important when deciding which gauge is required they cannot be easily adapted because they fit into the engine block

A2 Bulb has a tapered seating and a 5/8" UNF Male Nut
K Type has 3/8" BSP female nut , either supplied with (31-363-415) 3/8 BSP Male to 5/8 UNF Male or (31-363-472-00) 3/8 BSP to 3/8NPT depending on the gauge part number, please call us if you are unsure

Mine looks like the one on the right of the picture with a female nut so doesn't have a tapered seat as I thought I am sure it doesn't have a sealing washer though.
Sorry to mislead.

I created the proper size copper washer by taking a standard size washer of the correct ID and then reducing the OD with a grinder.

Keith,

Might an O ring do the job?

Richard Hawkins

FairView Fittings
120-C fits the male threaded sender/sensor

Two-seater elans have a capillary tube sender for the water temperature. Does a Plus 2 have an electrical sender?

Capillary senders are PLUMBING fittings, you seal them with some PTFE tape, not copper washers.

billwill wrote:Two-seater elans have a capillary tube sender for the water temperature. Does a Plus 2 have an electrical sender?

Yes, at least mine does.

'morning gents and nerds,

The kettle for the smith temp. sensor is supplied with a thin copper washer.
These can be supplied from Caerbont automotive instruments .Most helpful but at a price!.
Best regards Claus Garde

Hi all. Thanks for all the Input.
It looks like I have sourced one now. They are really hard to find, a completely non standard size. I was considering getting a M12 one and machining it to size as 1owner suggested but how to hold it while turning it? Would have to make some sort of jig first.
But anyway, I eventually got a reply from speedy cables who apparently make them themselves, I assume as above by machining standard ones down. They are going to send me some (fingers crossed). I guess Speedy cables and Carebont are the same company since they have the same address (except for one digit in the post code).
Hopefully get the car back going again soon (not that I can drive much in these strange times).
Keith.