Does my thermostat & temp sensor need changing

[Quattro Singh]

Been told the temp should stay at 90c (in the middle on the s3) but with the weather being cold if i'm driving the car on the motorway in 6th at about 3/4rpm instant MPG will show around 40/50 depending on road gradient the temp can go as low as the first line, i just put it down to good cold airflow and cruising at a constant pace, surely if your not booting it the temp won't stay at 90c (in the middle)

My fuel economy isn't bad either i get around 24/26 average MPG for around town driving and about 280/300miles on a full tank in this weather and about 300/320 miles in the summer the car has a stage 1 revo remap

 

[Lodhiz]

Hi Quattro Singh,
Your temperature gauge should remain at 90c after a few minutes of driving. I initially had the same problem as you as well, but after changing the thermostat my gauge always read 90. I think the reason it's important to have the gauge at the correct temp is down to fueling mixtures. If the car thinks it isn't up to temperature then you could be running rich (someone correct me if I am wrong). So essentially you could see a slight improvement in MPG once fixed, although what you're returning right now is pretty good.

Hope this helps.

 

[LennardS3]

Replace your thermostat and the problem is fixed.

 

[Quattro Singh]

Exactly Lodhiz because of the good mpg i'm getting i'm thinking its fine

 

[Lodhiz]

I'm actually really surprised at how much you return. I only average around 22/23 MPG around town if i'm lucky, and it will creep up to about 28 MPG on the motorway, so kudos to you!

No harm in changing the Thermostat though. It's a cheap part (I picked up a brand new one from GSF for £10) and can be done quite easily by yourself. If you do have a go at changing it, let us know how you get on!

 

[Quattro Singh]

yeah as you say there cheap parts

 

[sirbobalot]

I had the same problem on my car the parts were so cheap I changed both thermo and temp sensor job done haven't had a problem since.

 

[epox]

Do the cts first, 5min tops. and see if that works first.
Thermostat can be a bit of a pain to do and refill with pink coolant.

mark

 

[JohnG238]

Hello
I had the same problem. Replacing the thermostat resolved it.
JohnG