Adverse effects of an overcooling engine?

[ben_r1]

Right on my daily runner, a mk1 1.4 Clio 1995, it's had a constant problem with it running very hot. I'm talking about it sitting right below the red zone on the gauge. Changed thermostat, radiator, fan switch, heater matrix and water pump all to no joy. Compression test come back fine and it doesn't lose any coolant.

So after running out of ideas I changed tactics, fitted a ktr low temp rad switch but still run red hot. Now the standard and replacement thermostat has 91 degrees stamped on it, quite high I thought, so I stuck a spare 197 thermostat in it at 75 degrees and bingo the car runs cool but it only ever gets to a quatre heat up the gauge.

Are there any adverse effects to an engines performance or lifespan by running it 16 degrees cooler? Fuel efficiency seems normal and the heaters are still red hot.

Thanks!

 

[newman90]

to be honest mate, you may find the car takes londer to heat up but thats about it as far as im away, in alot of my track cars etc i didnt even run a thermostat and had no issues

 

[Willis]

in alot of my track cars etc i didnt even run a thermostat and had no issues

+1.

I had a 205 GTi 1.6 which was a bugger for being warm. Used it in all weather (it was my daily driver at the time) without a Thermostat fitted and it ran so much better then with one on. Strange. Just had to be really disciplined and not use too much throttle until she was nice and warm. Which took FOREVER in the winter. :001_rolleyes:

 

[930Tech]

With modern cars now with everything controlled by the ECU it's getting the same reading as your gauge so might be over fueling thinking it's still cold.

This is a problem on the twin spark alfas, the thermostat breaks down, the temprature runs lower and the fuel consumption goes up.

 

[Foxspeed]

With modern cars now with everything controlled by the ECU it's getting the same reading as your gauge so might be over fueling thinking it's still cold.

This is a problem on the twin spark alfas, the thermostat breaks down, the temprature runs lower and the fuel consumption goes up.

and the "over-fuelling" can cause rapid engine wear............

 

[930Tech]

I think it would take a time but eventually yes.

It'd not be like a cosworth type of thing with bore wash but it would be using more fuel.

The cold weather is not helping, have you tried blocking off part of the rad? some card should do it.

 

[richandgem]

Aren't thermostats supposed to open at 80 degree?

 

[sideways danny]

Aren't thermostats supposed to open at 80 degree?

on the majority of cars a summer stat opens at 82 and a winter stat around 88. Most will only ever see a winter stat

 

[A2ON]

in the vxr i had a spell on not runing a thermostat and then changed back to a cool stat 82 degree opening stat .

no uprated rad and on track days never exceed 100 degrees .

try it with the stat out but the heater will take ages to warm up and also is there a deeper problem that is causing these issues?

 

[ben_r1]

Dunno its somewhat of an ongoing issue which has seen every single part of the cooling system changed from the matrix to the pump etc.

The original thermostat runs at 91 degrees and has been confirmed to be correct OEM settings, but it seems too hot and sits right at the top end of the gauge!?

I'm happy to use the 75 degrees 197 stat but need to be sure it wont bugger my engine running it 15 degrees cooler? As said heaters are still hot and fuel consumption seems perfectly normal?