Hot start problem 1.8t


Registered User
Jul 22, 2009
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Hi, I have a 1.8t a3. I have recently noticed a problem that keeps reaccuring more and more often.
Basically my car is finding it hard to start when the engine is hot, but perfectly fine when cold. I believe it could be something to do with the coolant temp sender after some research. Also my temp gauge shows just over 90 after driving for a short while, i dont know if this has anything to do with it.
any help would be greatly appreciated :D


coolant sensor is most likely for hot start issues, and cheapest to replace.

thermostat over 90 is a bit of a worrier though, as it suggests a real coolant temperature of over 100. Have a look on vag-com to get your real coolant temperature.

Whats the milage on the car? has the waterpump even been changed? It could be a stuck shut thermostat (unlikely, as it usually sticks open and over-cools), but more likely to be a broken waterpump if its overheating.
Thanks for the info :D

as for the temp, it isnt majorly over 90 but only fractionally, probably wouldnt notice it if you had a quite glance at the gauge.
I believe the waterpump has been done quite recently as the car is quite new to me.


only way to tell the real temperature is on vag-com, the dash gauge is worse than crap. Every audi i've seen in working order has the temperature gauge dead centre.

When my thermostat went, it would read ever so slightly below 90 (needle was still touching the 90) , but vag-com said it was fluctuating between 60 and 75.