Well, after telling all my family and friends last week that my £150 Sei is my fave car ive owned (in 40 odd cars) it decided to let me down last night and the temp gauge went upto 118 degrees (it runs a scanguage2).

No mayo, no smoke, no odd noises, no loss in power, no bubbling coolant (or brown water in this case...) intake temps of 21 degrees, water present in the system, no leaks, oil in the system.

the temp went up quicker than normal, and fan came on at 97 as usual if stuck in heavy traffic, but even with the fan on and the heaters on full pelt (heat coming out warm) the temp continued to rise.

tried again today, and turned it off at 101 degrees to avoid risking any damage.

im thinking themostat is stuck? (normally when heating up it gets to 92 or so then drops to 85 (stat opening) then hovers around 90 ish.

anyone else had this problem?

cheers in advance

It would be unusual for the thermostat to stick shut, but not impossible.

But it sounds like you are not running proper coolant, so a blockage is possible.

I'd take a very close look at the rad. once the zigzag fins corrode the cooling ability rapidly falls away.

rad fins looked fine, but im taking the bumper off anyway, so i'll double check both sides of the rad. cheers

Back flush the rad, you might be horrified.

D

I agree that could be the thermostat but i want to ask if your oil and coolant is normal or some sort of soapy. (Sorry about my english.)

oil was fine.

Emptied the (very) dirty coolant out, oil out and put the new sump, thermostat, timing belt, tensioner bearing, header tank, water pump and aux belt on the last couple of days, and as soon as I can tension the belts properly, i'll whack the new coolant in, and see how it all runs....

old waterpump seemed pretty grotty, but span freely, so I'm not suspecting that. Rad fins and flush out were fine, as expected (dirty coolant)

i'll report back in a couple of days....

success.

car now gets up to temperature, runs cooler, and the fan kicks in at 97 (on the scangauge) and instantly drops to the low 90s.

did have one small problems getting it to start simply as the low aux belt pulley didnt have the pin lined up. But this forum gave me the answer, and 'il picolo bastardo' started off the key.

just waiting for my 40mm throttle body to turn up now, and the fun shall commence