Hello Guys,

I have a small problem with my coolant temperature.

Both Coolant fans are working in slow and fast speed

AC is working OK and is cooling perfectly

Fuse over battery are ok and not melted

When I am at stop light the coolant temperature rise a little bit from 90º to 95º (Please check the photo) It does not rise more than that.

When I beguin to drive, the colant temperature go back to the midle (90º)

Also, one day that I saw the temperature in 95º, I turn off the engine, wait a little and then start again the engine........ The temperature goes to 100º and a few sec later go back to 90º

I was thinking the Termo Switch was not working but I open the hood and I see both fans are wotking in hi speed and then they cycle to slow speed.

This problem happened after I took the car a weeks ago to the VW Dealer to fix a small leak on a coolant hose 1J0 122 109AQ that is near the colant reservoir and when they gave me back the car, I notice they put me in a bag the damage hose part + two empty G12++ Coolant 32onz bottles.

I was curious because I am pretty sure when the replace that small hose some of the coolant loss on the floor and they need to add more but I was think that maybe one bottle pluss water was enoughf...............So when I ask the mechanic guy, he says he put the 2 bottles and they do not mixed it with water and that this is OK

Here in my coutry the weather is very hot. I know the G12++ Coolant has to be mixed 50/50..............Can this be my problem that the coolant temperature rise a little.

THX

Maybe they got an airlock in the system when they put the new coolant in? The gauge should go up and down in traffic but usually it goes up to 100-110 then the radiator fan will kick in and it will go down to 90 again

Stuck thermostat or air lock or blown head gasket.

temp gauge should be at 90 constantly - deviation from this is not normal

I was going to go for sticky thermostat, but given the garage appear to have changed the coolant I am going to plump for airlock instead.

Hello Guys,

THX for all your replys. How do I bleed the Airlock? Is there is a Step by Step guide?

Can any of you explain how to bleed the system Or point me to a DYI.

THX

Isaac

Maybe they got an airlock in the system when they put the new coolant in? The gauge should go up and down in traffic but usually it goes up to 100-110 then the radiator fan will kick in and it will go down to 90 again

If yours is doing that mate its not working properly! They sit at 90 Degrees no matter what. Fan switch might not be working properly, or you've got a sticky thermostat!

I've had something similar happen before sat at lights and it was the thermostat that had gone. Wasn't an Octavia but its a universal issue. Would be my first check.

An airlock is really very easy to sort. Start the car, it helps if its warm as its quicker, but take the expansion cap off slowly. Be careful not to burn your hands on coolant! Do it slowly and you can make sure it doesn't overflow too quickly. Then once its off just let it run. It'll bubble slightly and if theres a proper airlock it'll most likely bubble a lot then overflow. Run it like this with the cap off for around 5 minutes, if theres no more bubbles put the cap back on and turn the car off.

Do it for as long as you need to to get rid of the lock!

I took the car to the dealer and they check all and toll me that the problem is the water pump. Since they want to charge me $280.00 for a new water pump with plastic impeller and 150.00 for hand labor. I tell them that I don't have money to fix it right know, that I will take the car to them in January. The guy toll me that they will remove the thermostat and leave the the engine without it to help the engine not overheat. I have the thermostat with me and I bring the car home and the temperature was always on 90º

I just order a complete timing belt kit with water pump with steel impeller for $259.00

So back at home, I open the hood and notice that they move a bracket were the accelerator cable goes and they leave it like you see in the pic. I really don't understand what was they checking in that hose........Do that hose has something to do with the coolant temperature?

I am curious, what that hose do? (Red Arrow) Why they move that part?

THX

Hey Guys,

Just to let you know that the problem was my Water Pump. As you can see on the attached pics, the factory water pump has a plastic impeller that with the time the plastic get brittle and then it cracks

My car is a 2002 with only 55,000 kms.

I took the opportunity to install a timing kit, GEBA water pump with steel impeller, new thermostat and new G-12++ Coolant

Isaac

Edited 28 December, 201114 yr by Turbo_Boss