How can I cool the engine?

[joaovc]

Hi

I have a Caterham Sigma 125 (Academy version) and I use the car as a daily driver. When I get stuck in traffic, even in relatively cold weather, the engine starts to heat considerably (needle starts climbing towards the red). The fan only comes on in the last mark before the red. What can I do to improve this? Should I get a more powerful fan? If so, which one? Is there any way to get the fan to turn on earlier (manually?).

Thanks in advance for your help :-)

[Incorrigible]

You can fit an additional switch but re you sure the engine is getting as hot as the gauge says it is ? They are notoriously unreliable

[CatMatt7]

The fan should kick in at around 80 degrees, which ought not to be too near the red. I would probably suggest that the fan cut in is at the right temperature and that the temp sender isn't.

My oil temp used to read 20 degrees hotter than it actually was.

Matt

[normalbloke]

Rather than guess and gather, buy an I/R thermometer and check the temperatures your engine is ACTUALLY getting to, not what your gauge may at best be vaguely indicating.

[pw75]

or you can just buy some temperature strips for a tenner and stick them on the rad..........saves getting out of the car in traffic

[Tango7]

I would have your car checked as to why it gets so hot in the first place. My Sigma car will sit and tickover for ages with the fan cutting in and out as you'd expect and the temp gauge staying pretty close to the middle (80) with no real deviation. Even yesterday at MIRA with temps near 30 degrees and the car ticking over for quite a while as we waited for our turn, the temp remained very stable

[joaovc]

Thanks for the helpful replies everybody

[Steve-B]

K series owners, myself included have installed a cooler thermostat from Rover, the 78-82C version. This opens the thremo sooner, so the cooling can happen quicker. Also there is a VW fan sensor available for not too much £ that is far more reliable we've installed.

Pro: cooler in K is better
Con: have to bleed and refill system, not necessarily a bad thing yearly....

[darren f]

If you do want to go the route of a manual switch (I did for my R300K, purely to save the 'will it / won't it' uncertainty with the fan switch when sitting in queues on hot trackdays) the instructions are on Chris W's excellent 'Electrickery' pages reproduced on the equally excellent Alchester Seven's Pages at the bottom here.

[Gingerbread Man]

My K Series used to run at 80 degree's ish. I've drained and refilled it to no avail. It now runs at 85/90ish.

I thought this was because of the thermostat (82 degree stat) not opening, but it must open as the fan comes on at roughly 100 degree's (all reads on my gauge).

So do the temp senders randomly go from correct reading to over reading?

Someone mentioned a VW van stat, any idea on the part number?

[Steve-B]

Gingerbread Man said:

Someone mentioned a VW van stat, any idea on the part number?

a search on the technical forum on the other site should find it. was about £15-20 squid i recall......

[darren f]

Is this the one?

[Gingerbread Man]

Steve-B said:

Gingerbread Man said:

Someone mentioned a VW van stat, any idea on the part number?

a search on the technical forum on the other site should find it. was about £15-20 squid i recall......

I tried a search on Blatchat, but I find the search function utter useless to use. Any more information on this?

If it's uber reliable, then I'm tempted. Does anyone know why the Caterham item goes wrong so easily?

[Steve-B]

a simple search on "THermostat" with a time of "from the beginning" yields http://www.blatchat.com/t.asp?id=184776

[joaovc]

Thanks again for your input, everybody :-)