I found that there was a water leak and the culprit was the aluminium casing at the rear of the cylinder head. Fortunately my spare cylinder head had one attached. I removed it to see wha sort of condition it was in and it appeared intact. I then removed the leaking one…photos attached I hope. Cleaned everything up, made a new gasket & refitted the replacement…needless to say the choke warning light doesn’t now work!
Oh yes, the heater(?) outlet pipe was a different diameter so I have to make up a replacement closure device, no heater in this car. ( a length of hose pipe suitably plugged!)
I noticed that the block drain tap barely worked, so that will need poking out!
Any comments on how to encourage the replacement casing to work the choke switch properly? It is a different pattern as the outlet pipe is different and stupidly I didn’t take a photograph of the replacement.
Any comments out there?
David
Choke control light
Re: Choke control light
The choke switch on my 47 12 is a small rectangular device which sits in the aluminum rear of head casting. Is that what one of yours is ? There are triangularish switches (Otter?) that do a similar job but so far I haven't seen one on a P2. Unfortunately, your photo(s) haven't turned up, it may have been their digital size, so it's hard to say more at this stage. The pre-Solex carb cars don't have this switch so the earlier blanking plates don't have the switch recess.
Re: Choke control light
The plate removed had a broken Paxolin (?)strip with a terminal.
The "new" one simply has a terminal!
I will try again to add pictures!
Rover water Jacket 3.jpeg
Rover water jacket 2.jpeg
Rover water jacket 1.jpeg
The "new" one simply has a terminal!
I will try again to add pictures!
Rover water Jacket 3.jpeg
Rover water jacket 2.jpeg
Rover water jacket 1.jpeg
Re: Choke control light
I don't think that worked! Trying again!
- Rover wateter Jacket 3.jpeg (49.9 KiB) Viewed 623 times
- Rover water jacket 2.jpeg (50.77 KiB) Viewed 623 times
- Rover water jacket 1.jpeg (50.17 KiB) Viewed 623 times
Re: Choke control light
Success...in al their furred up glory!
Re: Choke control light
Well done with the photos !
Right this minute, this may not be the greatest help to you but this the picture above is same as the new switch I bought and fitted. However, after about three years but 100 miles, it has stopped working again and as the car in question is one that has to live off site, I have yet to have a proper look to see what has happened.
The switch will be a thermostatic one, so when it heats up the terminal (from the light) makes contact with earth and the driver knows to put the choke in and go from 4 mpg to 20 mpg . Reading back your original post, there will need to be a good earth between the rear casting (and switch) and earth.
However, there is also another switch at the cold start control and this is a mechanical brake light switch playing another role and subject to the same potential failings of its mate on the brakes. A test meter should reveal what is working and what is not.
I think the new casting I fitted to the 12 was the only one I had which accommodates this switch, the others are plain unfortunately. The closing plate is a different part number for the 6 cylinder cars compared to the fours, so that may be a possibility as to where a difference has lain. As I have replaced the 1946 14's casting too, I am hoping never to have to replace either again hence the lack of new ones in the cupboard to photograph.
It would seem quite possible to rig up a thermostatic switch, say from an electric fan, install it somewhere (allowing for the temperature difference between the rear of head temperature and the new sensor location), set it to the appropriate temperature and it should work. Whether the cost and work is worth it compared to buying the correct items, not for me to say, but it would seem possible should the bits be to hand.
- Screenshot_20260307-101615.png (32.53 KiB) Viewed 283 times
The switch will be a thermostatic one, so when it heats up the terminal (from the light) makes contact with earth and the driver knows to put the choke in and go from 4 mpg to 20 mpg . Reading back your original post, there will need to be a good earth between the rear casting (and switch) and earth.
However, there is also another switch at the cold start control and this is a mechanical brake light switch playing another role and subject to the same potential failings of its mate on the brakes. A test meter should reveal what is working and what is not.
I think the new casting I fitted to the 12 was the only one I had which accommodates this switch, the others are plain unfortunately. The closing plate is a different part number for the 6 cylinder cars compared to the fours, so that may be a possibility as to where a difference has lain. As I have replaced the 1946 14's casting too, I am hoping never to have to replace either again hence the lack of new ones in the cupboard to photograph.
It would seem quite possible to rig up a thermostatic switch, say from an electric fan, install it somewhere (allowing for the temperature difference between the rear of head temperature and the new sensor location), set it to the appropriate temperature and it should work. Whether the cost and work is worth it compared to buying the correct items, not for me to say, but it would seem possible should the bits be to hand.