MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: GilesWoodward59 on May 26, 2023, 11:36:16 pm

Title: Temperature gauge reading drops in heavy traffic
Post by: GilesWoodward59 on May 26, 2023, 11:36:16 pm

Odd experience the other day… spent 20mins crawling up a steep hill due to a traffic jam, outside temperature was warm / sunny so I kept an eye on the temp gauge (out of boredom tbh) and noticed that the gauge reading dropped down to around 70 degs when stationary and back up to 90 degs when I moved off again. Very visible movement on the needle each time I stopped / restarted.

Only other thing I’ve noticed is the car has used some oil (probable 0.5 ltr in the last 5000 miles). No mayo under the oil filler cap and coolant levels fine / clear pink colour.

Any thoughts on what’s going on? I’ve never had this happen on a car I’ve owned before. Dodgy thermostat perhaps? Amazingly efficient cooling system? I do have an r-tech turbo heat shield fitted plus Revo intake & TOP but I can’t see these making much of a difference.

Title: Re: Temperature gauge reading drops in heavy traffic
Post by: Octoparrot on May 27, 2023, 10:49:53 pm

Sounds like the thermostat to me,  very common.

Title: Re: Temperature gauge reading drops in heavy traffic
Post by: GilesWoodward59 on May 27, 2023, 10:55:44 pm

Thanks. It’s already booked in for a service so hopefully have caught it before it become too much of a problem.

Title: Re: Temperature gauge reading drops in heavy traffic
Post by: GilesWoodward59 on June 08, 2023, 04:50:43 pm

Just to follow this up, it was indeed the thermostat at fault. Thanks @Octoparrot (https://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=14844)