Thermostat

Needless · Post by **Needless** » 25 Mar 2005, 13:57

Going to fit an alloy rad to my MK1 VTS soon, and was recommended to change the thermostat too.
Apparently on a saxo the thermostat opens at about 90degs - are there ones that open at a lower temperature? Someone said that Gti6 one opens at 83 and might be the same fitment as the Saxo?
Is this right? Thanks. [:)]

jeremy · Post by **jeremy** » 25 Mar 2005, 14:34

I think changing the operating temp may muck up the fuel injection - why do it? If its overheating lowering the thermostat temp won't help.
I'm almost certain you have an alloy radiator anyway. Steel or copper haven't been fitted for years now (like 20 years)
If you suspect a dropping off of cooling perforance you may be able to help by flushing. Your radiator is probably crossflow which means the flow is from side to side and any sludge blocks the tubes from the bottom up. You may be able to feel a cold area at the bottom and a good flush may shift the muck. Best to take the rad out to flush and work from both ends. It can take hours before it runs clean. Remember the block may be dirty too.
Jeremy

Needless · Post by **Needless** » 25 Mar 2005, 15:38

Thanks for reply.
My current radiator is in quite a state, and an alloy radiator was only a bit more expensive, so I got one. Not sure if their anymore efficient though. I've read the Haynes etc on flushing and have the ready mixed coolant/anti-freeze ready to use before I install it!!
Just a couple of people mentioned they have different thermostats on their cars. I dont know whether it will effect the fuel injection?

jeremy · Post by **jeremy** » 25 Mar 2005, 15:49

It will depend on the values of the various sensors measuring heat. Some people claim to improve performance by tinkering with the cold start system - either by altering the value of the sensor output (ie different sensor, perhaps a resistor in series. the idea is that the management system enriches the mixture when cold and this tapers off as the car warms up. If you can persuade the thing its hasn't fully warmed up - then it will run a little richer which MAY improve performance.
I suppose you can achieve the same effect by running the engine at a lower temperature by using a lower value thermostat.
It may work - it may do other damage long term but apart from higher emmissions I wouldn't have thought the risk was that great.
You will have a catalyst - which may be at risk from an enriched mixture.
jeremy

Stuart McB · Post by **Stuart McB** » 26 Mar 2005, 00:04

Saxo VTS. I thought that was a different engine to the Pug GTI6. Different engines would have different stats in them. For your VTS I'd put a new stat in after you flush the system through but stick to the same rating.

NeilVTS · Post by **NeilVTS** » 07 Jun 2005, 15:42

I think the people with modified vts'(s/c'd t/c'd cammed etc)change the std 88c vts stat for a 82c gti6 stat to help it run cooler as obviously you will be running higher temps/compression. So if your car has been modified, then yeah its worth doing, but if it runs at normal operating temp theres no point in changing stats.

wilkobob · Post by **wilkobob** » 07 Jun 2005, 17:29

Just a point... im sure the radiator I removed from my ZX TD 2 months ago was copper? it was copper coloured where paint had flaked off and went blue where water had been on it when it was left out side... any thoughts? Im not sure what the new one is made of as its painted black