Overheating Crossflow

[Tyrone]

On the way to the Blue Light, I had what appeared to be classic symptoms of head gasket failure. Petrolhead and the man from the RAC concurred. When I got down to raplacing the gasket I ignored signs to the contrary, no emulsion, coolant still coolant coloured until the head gasket was exposed and there wasn't anything wrong with it, again seconded and thirded by a mechanical neighbour and Iain A (Duratec man). Thermostat duly tested and did bugger all. Replaced thermostat and everything appears sweet, except the temperature guage (gauge) is moving between 80 and 100 degrees. With no apparent correlation with speed or revs. The guage needs recalibrating but could it or the sender been damaged somehow following the initial overheating episode. Or am I barking up the wrong tree. Help!

Bri

[Graham Perry]

If you have the absolutely standard Caterham crossflow cooling system it was never very good and often strange things occurred. Many of us have fitted header tanks for this reason. A search of the archive should bring something up as crossflow cooling or lack of it has been discussed many times

[Graham Sewell]

Getting hold of an 82'C thermostat is near impossible. The standard one now supplied for X-flows by Caterham and James Whiting are 92'C which will look damn close to 100'C on the guage if looked at from the driver's seat.

 

this is normal behaviour and although a little shocking at first is actually OK. I would suggest putting in a matching radiator fan switch - else the normall 88'C one will be permanently on.

 

Low tech luddite - xflow and proud!

[Manxseven]

from an earlier posting;

 

The 74deg stats are available from your local Partco.

 

They are made by Quinton Hazell.

 

Part No. QTH101

 

Cost: 4.75UKP

 

Give them a ring to order one before you go

 

Hope that helps

 

Simon Emmens Caterham and Pussy Photos here 😬

[Tyrone]

The fan comes on when the temp gauge is showing 110 degrees which is why I think the gauge needs recalibrating (can they be recalibrated). Should the thermostat be rated lower or higher than the fan switch? Before the incident the gauge showed a steady 90 degrees (although I'm assuming the actual temp was lower) and only started to rise when in stationary traffic. Now, it does vary. The new thermostat was a 92 and replaced an 82, is this relevant. Could the sender be goosed?

Sorry for all the questions, but you know how paranoia sets in after a significant failure.

Thanks

Brian

[NickW]

Brian,

 

The expert opinion is that a tuned Xflow is happier at a lower temp, so a 74deg stat is used. This gives a temp gauge reading of about 80deg in normal conditions.

 

Not sure if you can recal the guage???

 

 

Nick.

[Tyrone]

Thanks for the help guys. I've ordered a 74 degree stat and a new sender. I'll pop them in and see what difference they make.

Cheers

Bri