New Car, new member! - Hyundai Performance Forums

Coupe_Mark · 07-06-2007, 08:08 PM

Hi guys, been registered on here before, quite some time ago, and thought I'd register again as I just picked up a new motor.

Managed to bag myself a totally standard 1994 SCoupe Turbo with 80,000 miles on the clock for the princely sum of £630 off Ebay! Car needs a few bits on the bodywork tidying up (few scratches here and there and a gouge where its been keyed), and definitely needs the tracking sorted. Other than that, can't say there's much wrong with it for the money!

One thing you guys may be able to help me with though. This is my second SCoupe Turbo, but my last one never did this. When driving, the temperature needle refuses to move off from cold, but when left idling at stand still it creeps up, and then back down again and up again etc... but never gets above half way. If you then drive it once the needle has risen, it goes back down quite quickly, and quicker the faster the car is moving. Now this to me would suggest that the rad is getting too much air through it. Either that or its a faulty temp sensor, or the thermostat is goosed. What do you guys think?

Also, as its a while since I've owned one of these, and I've been out of touch, does anyone have any decent links to companies in the UK stocking aftermarket/performance parts for the car? I know there aren't many, but I've lost all my old links!

Anyway, cheers in advance guys, I'll get some piccies up soon.

03-Accent-03 · 07-06-2007, 08:45 PM

Welcome back

Coupe_Mark · 07-09-2007, 07:12 PM

No-one got any idea's or advice or past experience then about the coolant temp thing? Been over everything and it all looks fine - seems to be quite a lot of pressure in the top radiator hose though.....

accent0002 · 07-09-2007, 07:19 PM

can you test the temp sensor? i wouldent think it would be the thermostat

Coupe_Mark · 07-09-2007, 10:41 PM

It seems too constant a thing for it to be the temp sensor - temp drops (and I mean to cold level on the gauge) when the car is moving, ie when the air is flowing through the rad, but temp increases when at standstill, but never goes above half way. The car isn't in danger of overheating, but if it really is getting that cold when driving, then that isn't good either, as the engine could be too cold for driving at high revs.

^scythe^ · 07-10-2007, 03:03 AM

You could try disconnecting the radiator fan...
See if that helps...

But i too say faulty temp sensor...
Its not doing what its meant to be doing therefore you should replace it...
It also might be a wiring fault...

Cheers
scythe

Coupe_Mark · 07-10-2007, 07:56 PM

Looking at the car today, it can't be a faulty temp sensor - so far as I can see, there are 2 sensors, one for the gauge and one to the ECU, and the way the car cools when moving is affecting the way the car runs - ie its richening the mixture which means the ECU is getting the same signal as the gauge. This must mean that it is actually getting too cold when driving, which would point towards to high coolant flow which could be caused by the thermostat sticking open - if this happens then there is nothing to regulate the flow of coolant. I have ordered a new thermostat as its a cheap thing to replace so we'll see how that works.

I don't know if its related, but today after driving the car quite a bit, the temperature rising when stopped and dropping while moving (this happening many times throughout the day) suddenly when I pulled to a stop, the revs went up to about 3500rpm (checked the throttle and it wasn't stuck open) so I switched the engine off. When I then tried the ignition again, it turned over but wouldn't start. Left it a few minutes and it started right up again but the revs rose again. I switched the car off, reset the ECU, then fired her up again - took much longer to start than normal but eventually fired and started and has been fine so far since. Has anyone else had this issue? My last one never did this!

^scythe^ · 07-11-2007, 06:04 AM

Could be a faulty throttle position sensor...
Or crank angle sensor...
You should get the codes read (try not to reset the ECU till you do)...

Cheers
scythe

Accent95 · 07-14-2007, 11:24 AM

Welcome back! Any pics yet?

Coupe_Mark · 07-14-2007, 11:40 AM

Well, I've sorted it - it was indeed a faulty thermostat - it was stuck partially open which allowed the car to warm up when standing, but the coolant was constantly being forced through it when driving it, causing it to cool down. It looked like the original thermostat from when the car was new as it had at least 10 years of sludge stuck in it! I've back flushed the coolant system and everything is well now.

No pictures yet, been very busy, and the car still needs a little tidying. Will get some up soon though.