S3 overheating - fixed - then broke again

[colicabcadam]

ok let me give you a breif heads up

in traffic one day, car boiled over, temp gage began to slowly increase its way to 110 (i was not too worried as my ducati often hits 105 in trafic) soon after that the low coolant light came on and the temp reached 115, i then switched the engine off

car before the fix...

-air con would not work
-fan does not kick in when engine is warm
-fan does not kick in when heating was turned on
-fan does not kick in when air con was turned on
-engine boils over (even though the gauge only shows 90?!?!)
-water pump does not stay on after ignition is turned off

i replaced the fan module, no luck after 2 weeks of more hunting and searching i found out the problem, a dirty fuse (the one that controls the fan module), it was not broken or blown, just dirty!

car after the fix (well i thought i fixed it)...

-air con works
-fan kicks in when engine is warm
-fan kicks in when heating was turned on
-fan kicks in when air con was turned on
-engine does not boil over
-water pump stays on after ignition is turned off for a short amount of time

woohoo i fixed it, for a little while

car now...

-air con works
-fan does not kick in when engine is warm
-fan kicks in when heating was turned on
-fan kicks in when air con was turned on
-engine boils over (even though the gauge only shows 90?!?!)
-water pump stays on after ignition is turned off for a short amount of time

so when the heating / air con is on, the car does not boil over!

any ideas? why on earth did the fan kick in when the engine warmed up after i initially fixed the bunch of problems by cleaning the fuse, then later on, stop kicking in even though the other problems are still non existant?? H!G!!

i have pure tap water in my car at the moment, i know the boiling point of water is 100 and around 115 for dedicated coolant, could this be causing a problem?

car's going in for a full service next week, but would just like a heads up and your opinions

another thing, when i say boil over, i mean steam comes out of the coolant tank liek a kettle when the lids on and it bubbles like a kettle when you take it off

sorry if i have bored you! lol

 

[colicabcadam]

ps - is there a coolant overflow on this car?

 

[s3dave]

i dont know what you mean by waterpump stops on after you turn the ignition off?? how can it
i would check the wiring under the fuse if possible...

 

[colicabcadam]

i dont know what you mean by waterpump stops on after you turn the ignition off?? how can it
i would check the wiring under the fuse if possible...

i believe (based on numerous threads on the internet) that the audi s3 has 2 water pumps, one powered by the engine cambelt and one powered by the cars electrics (the one close to the radiator) correct me if i am wrong.

either way, there is defo something spining / making a noise after the ignition is turned off, which never happened before i fixed the fuse problem!

 

[s3dave]

the only thing that spins on mine is the secondary air pump sometimes, did not know they had a secondary electric waterpump?

 

[jojo]

the only thing that spins on mine is the secondary air pump sometimes, did not know they had a secondary electric waterpump?

The S3 has a second coolant pump that keeps the coolant flowing after the engine is switched off. You can hear it whine lightly from the front end when you get out.

 

[s3dave]

The S3 has a second coolant pump that keeps the coolant flowing after the engine is switched off. You can hear it whine lightly from the front end when you get out.

cheers jojo may have to check my fuses then......lol

 

[colicabcadam]

cheers jojo may have to check my fuses then......lol

fyi the pump is located to left of the radiator (facing the car, you cant miss it)

 

[s3dave]

cheers, back on topic then....lol

 

[S3PEG]

have you replaced your temp sender... fairly cheap and easy fix!