Warning! Thermostat on some 08 cars

[gdr]

Here is something I discovered a couple of days ago now confirmed as a known problem with some new Exige S 240s and possibly Elise S/C. I thought worth warning others about it if you are not already aware, potentially dangerous IMHO.
Having put >600 miles on new engine I began to give it a bit of revs briefly (run it in by the book me) and noticed after a quick zip up to 6000 rpm or so, a sudden drop in engine temp, from 88C to 77C. Thought this was a bit odd. That evening when browsing Pistonheads I noticed a post by a guy who had his Elise SC cut out on him while giving it beans round a corner resulting in a spin (no harm done luckily) - cause was the engine temp suddenly dropping below the warm-up threshold whereby the ECU cold engine limiter (6000 rpm) cut in. Fault traced to a dodgy thermostat, I think it could be opening too quickly when the engine is revved, resulting in all the relatively cool water from the radiator (if you have just been pootling along) suddenly getting into the engine too quickly. Lotus apparently have recently become aware of this and the chap had the stat changed, working OK now.
I called MMC this morning, and sure enough, service dept have become aware of this problem and they are changing thermostat on afflicted cars. Done one Exige 240 already apparently. I will finish the running in in a week or so (keeping revs down!) and will get my stat changed at the 1000 mile service. Would not want this to happen if overtaking, and in any event, such sudden temp fluctuations will not do a highly stressed engine much good.
Hopefully MMC will catch all affected cars recently delivered up here, but I believe it should really be up to Lotus to recall.....

[steve_weegie]

There's definatly a dodgy batch of thermostats doing the rounds at the moment.... The three I've seen recently from a well known supplier have all had the wrong spring rate, causing these symptoms too..... Beware!