Coolant and temp issues

[Bobby Valentino]

Since I got the car i have been having varying issues with temperature not runing right, usually sits at 80 unless you floor it then goes upto 90 and if you ease off back to 80, think its thermostat related, then today drove for 20mins, stopped the car, when i started it up again coolant light came on, and the level was very low, so topped it up only to find out that when i got home, 10miles up the road my level was very high. Am i right in suspected my thermostat is sticking, either on or off...

[Rhyso]

 id start by replacing the thermostat and temp sender and get the system checked for leaks along with a cylinder head check to determine where you coolant is going

[tdi_blu]

As already said thermo and temperature sensor would be the first things I would go for.I had a similar issue with my old gt tdi both had gone once I replaced them it was fine.Do you know if the car has every had a new water pump as they are well known for failing as the old ones had plastic propellers which would break over time.

[Bobby Valentino]

Am going to, but it seems that it hasnt leaked, it has shot up to way past max now, like it has recirculated but was stuck in the system when the light came on, now it has gone back in the expansion tank, will get thrmostat tomoz and stick it on...

I believe the pump was done with the last cambelt around 10k ago, am pretty sure they did both...

[tdi_blu]

If your pumps been done then that's one thing eliminated I'm sure if your thermostat gets stuck your hot air won't come through either on your heater so it will be cold until it decides to open.Hope your sort it out anyway 

[Bobby Valentino]

Thanks for the help, will see how i get on over the weekend weather permitting....