MK5 Golf GTI

All Things Mk5 => Modifications & Technical Area => Technical Workshop => Topic started by: DMackie on May 05, 2017, 10:46:43 am

Title: Fan Issue
Post by: DMackie on May 05, 2017, 10:46:43 am

Hi there

I have an issue with one of my fans coming on even when the engine isnt even hot.

I think the main thermostat has failed as the temp gauge takes a long time to get to 90 degree. What are the causes of the fan coming on randomly?

Ive heard that the sensor on the big fan can be an issue but want a few things to try so i can get this issue fixed.

Thanks in advance

Title: Re: Fan Issue
Post by: lukemk5gti on May 05, 2017, 11:07:47 am

Main thermostat shouldn't be the culprit. Both of my thermostats were gone and the fan wasn't an issue.

My gf has the fan issue too so I'm interested in finding out the problem.

Side note, she had a leaking water pump so her coolant system wasn't working right.

Title: Re: Fan Issue
Post by: pudding on May 05, 2017, 12:20:21 pm

Is the climate control in 'auto' ?

Does the fan stay on when the car is switched off?

Title: Re: Fan Issue
Post by: DMackie on May 05, 2017, 12:24:21 pm

Id have to check the climate control settings. It is in the garage having some other things done atm.

The fan does stay on after ive turned the car off at times.

Title: Re: Fan Issue
Post by: pudding on May 05, 2017, 03:12:45 pm

The fans come on if the climate is in Auto, along with an increase in idle speed to compensate for the engine load.  If it's switched to "Econ", the revs drop and the fans definitely go off, providing it hasn't triggered the water temp trigger.

Sometimes the fan will stay on along with the after run electric pump, depending on water temp.