MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: moskii00 on January 05, 2025, 05:45:41 pm

Title: Temp Flactuating when it hits 70
Post by: moskii00 on January 05, 2025, 05:45:41 pm

Hi,

My temp is still fluctuating one it hits 70 and never reaches 90 for awhile, it keeps going under 70 and above by a little. I have so far changed the inline stat and the temp sensor and the temp is still fluctuating, should i go for the main stat next?

Title: Re: Temp Flactuating when it hits 70
Post by: ZoliWorks on January 16, 2025, 07:20:21 am

Always start with the main thermostat. That's the one that goes bad and is the most responsible for temp issues.

Title: Re: Temp Flactuating when it hits 70
Post by: mjmallia on January 16, 2025, 08:11:56 am

As mentioned the main stat should be changed.  With the alternator out and undertray out.........some patience, jigging, unplugging and time, it can be done on the drive for the cost of parts.

Remember to order the O-ring for a pipe seal, as it is not included and do not want to have leaks after all the faff of fitting it.....red arrow

Good guide here:
https://pelicanparts.com/techarticles/Volkswagen_Golf_GTI_Mk_V/31-WATER-Replacing_Your_Thermostat/31-WATER-Replacing_Your_Thermostat.htm

(https://i.postimg.cc/QttWWmfM/cooling-system.jpg)

Title: Re: Temp Flactuating when it hits 70
Post by: PorkPieBandit on January 18, 2025, 11:06:11 am

I did my main thermostat recently and found that pelican guide really useful. This video is handy too

I'd also really recommend some flexible hose clamp pliers, I bought some especially and I would have struggled without. Not the exact set I got but this type of thing - https://www.amazon.co.uk/Dapetz%C2%AE-Flexible-Reach-Clamp-Pliers/dp/B08HQS9552/ref=asc_df_B08HQS9552?mcid=448ae44ac9dd3013b3c5db9c8a8aa842&tag=googshopuk-21&linkCode=df0&hvadid=697205530764&hvpos=&hvnetw=g&hvrand=5704810594983826337&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9045888&hvtargid=pla-1723050376478&psc=1&gad_source=1