Cooling Issues

Hi guys . I attended the Harrogate MG classic car show this weekend and a member of my club ( Leeds MG & CCC ) arrived having had to queue in traffic on what was a rather stuffy warm day and , the inevitable TF boiling issue happened . We let it cool and I had a quick look around the header tank and found evidence of a bit of coolant around the seam . The TF is a 53 plate and had an after market low level warning system fitted . The owner told me that he would like to have the factory fitted system rather than the one fitted to his as the brass topped float switch in the header tank neck was stuck fast and it made life difficult when it came to topping up. I did inform him that the factory fitted ones were wired up through the Pektron BCU and , his TF was a Lucas BCU . His header tank on closer inspection was well passed its sell by date as it was full of cracks and I did suggest he considered renewing it . My question is would the later header tank and sensor work with his after market system ? I can't see any problems as I have tested the voltage on my 05 TF sensor plug and got a voltage of just over 10 volts and this more than likely due to it being routed through the BCU. The voltage at the after market sensor was full battery voltage ( 12.3 volts ) . Both systems use a floating switch so unless the forum boffins can see any problems , I am going to tell him to get the later type tank and sensor . It's me that's going to be doing the job so I thought I would pose the question . As always I await an avalanche of replies . :broon:

John

I don't see any reason why that wouldn't work.

I always ask, so were the fans running?

Good morning David . Yes they were . A week before this happened I put pscan on to watch live data and found that only the engine bay fan was running . He sourced and fitted a second hand one and that cured that fault . He has had someone ' mess' with the car , ie had a new temp sender fitted and the jiggle valve removed from the intake manifold and I just wondered if they hadn't bled the system fully . At the show on Sunday there was definitely a sign of coolant around the seam of the header but no sign of it coming from the cap which he informed me is new . I think it's worth a shot at replacing the header tank with the genuine sensor type as the after market version has the pick up for the switch float cable tied to the base of the header which doesn't look good !
John

My low level sensor is wired as follows - constant live 12v to the redundant cat overheat warning on the dash - wire to the header tank switch - wire to earth.

The header tank is from a Rover Streetwise (Rover 25 on steroids running MEMS 3).

It is on a constant live so I know if there has been a leak as soon as I get in the car.

And the point of my post - to say that you can use a MEMS 3 tank on an earlier car.

Thanks for that TC. I kinda thought it would be ok . It's just when it's someone else's money , I sort of had a doubt in my mind . As I said previously the system that's fitted to the TF in question is a bit ropey and not what I would put up with as the guy has told me the low level warning goes off if he goes round a corner fast , which would drive me nuts .
John

Ps how's your clutch arm? Have you sorted it .

Ok , so this afternoon I successfuly removed and fitted the later spec coolant tank and sensor on my mates TF, tidied up the wiring with a genuine amp plug to the sensor and filled with coolant. I then thought I would just push the float down to test the warning system in the cabin , working ok. Ran the car up to normal temperature with no issues and waited for the fans to operate, which they did .Road tested for five miles without issue . Parked up and checked for leaks . All good with the car and no signs of boiling . :broon: