Running Cold

[Viper Stuart]

Looking for opinions. Was out tonight and noticed car seemed to running colder than normal by about 15 degrees ( euro spec 98gts and usually sits with needle vertical at 90 degres). Got home and let it idle for 10 mins and gauge went to 90 but no higher. However fan had kicked in by 90 and normally it wouldn't come on til about 100 . So
1. Is there a sensor that links to the gauge that could be faulty
2. Is the fan controlled by a different sensor which would appear to be working correctly
3. Is it a thermostat problem
Any help appreciated
Stuart

[Ginja]

I'm definitely not the expert but I have replaced the temperature sender on mine although the symptoms on mine were that it read high. Apparently this is a common fault. The fan relays seem to be flakey as well but they seem to result in the fan not coming on. Also do you have any air in the system - you can burp it by squeezing the top coolant pipe.

[sssammm]

Thermostat could be staying open

[Viper Stuart]

thanks guys. Was kinda hoping it was just the coolant sensor. However I started the car from cold tonight and the top hose pipe heats up quickly in sink with the engine and not after the engine gets hot so looks like thermostat open. Having read Marks write up last week on changing his I know what's ahead of me. Don't know whether to be confident or worried!

[Dr-Bob]

There not to bad to do.......... May have the gaskets here as well

[V10 SPM]

So if I start up my GTS from cold and let it idle, approximately how long should it take before the fan cuts in?

[fatboy18]

I Also have new inlet manifold gaskets, thermostat gasket, and coolant temp sensor here in the UK (Do not have spare thermostat).

If you are going to change out anything I would recommend replacement rad hoses.

[fatboy18]

V10 SPM said:

So if I start up my GTS from cold and let it idle, approximately how long should it take before the fan cuts in?

should cut in when temp needle gets to about 1ock

[Viper Stuart]

my fan is kicking in at 12 o'clock when it used to be 1 o'clock. If the thermostat is now stuck slightly open making it run cooler then I don't see why that should affect the fan cut in temp. I believe the sensor sends signal to both the gauge and the ECU ,so have ordered a new sensor and will see what difference it makes ,if any,before changing stat.

[fatboy18]

Viper Stuart said:

my fan is kicking in at 12 o'clock when it used to be 1 o'clock. If the thermostat is now stuck slightly open making it run cooler then I don't see why that should affect the fan cut in temp. I believe the sensor sends signal to both the gauge and the ECU ,so have ordered a new sensor and will see what difference it makes ,if any,before changing stat.

No need to drain the coolant when changing the Temp sensor, you will need a 1 inch deep socket to remove the sensor, be careful, the black plastic top of the sensor is brittle, also make sure you do not put the sensor back in at an angle, its a tapered thread so its easy to get wrong. Try to put it back in by hand for the first couple of turns to make sure its square to the hole

I got mine from Rock Auto, fedex fast shipping all duty paid, super fast service got it within 72 hrs.

[Viper Stuart]

thanks for the heads up on the coolant! I was mulling over whether to drain it or not but decision made. Cheers

[Viper Stuart]

New sensor fitted and all is back to normal. Thanks to those that offered gaskets and to Billy Whizz and VPRMAN Colin who genuinely offered their time had the stat needed changing!

[BillyWhizz888]

Great news was only the sensor

Gutted at the same time you know what I mean

See you at next meet or 2