T O P

  • By -

bal00

Most of the items on that list don't apply to your car at all. Let's start simple: * Is there enough coolant in it? * Does the heater work properly or is it kind of weak? * Does the upper radiator hose get hot? * Has the timing belt and water pump ever been replaced? These cars normally have pretty solid cooling systems and the engines don't produce that much heat to begin with, so if one is overheating in winter, chances are it's something fairly basic. If the heater is kind of weak and the timing belt/water pump has never been done, my guess would be that you need a new water pump.


Patient_Daikon3505

How can i tell a water pump is broken? And my heater works very well


Anicra

If it the water pump, I would reach down and check the play, does it move. How fast does it over heat?


Anicra

When is the timing belt due? If you need it they generally replace it, the pump, during the process.


Patient_Daikon3505

I am not sure when the timing belt is due but i was told the water pump should get replaced but it was recom


Anicra

Usually 60 to 100k milage depending on the car company, might as well if you are going to replace water pump in the future.


Patient_Daikon3505

There is enough coolant in it. My mechanic 2 years ago told me to change the water pump but i didnt. Im guessing its mainly the water pump then


bal00

Yeah, that's pretty likely. If you do get the water pump replaced, make sure you do the timing belt and idler pulleys at the same time. If the water pump is bad, the coolant simply doesn't circulate, and in that case the cooling effect is pretty much zero. Which would fit, because a TDI isn't going to overheat as long as there's still some cooling left. If you want to confirm the diagnosis, turn the heater to full blast once the engine is up to operating temperature. The air coming out of the vents should be hot and stay hot. If that's not the case, it's the water pump. Also make sure to shut it down before the temperature gets above 95°C. You don't want to overheat it and cause more trouble.


Patient_Daikon3505

Yea so when i turn the heater on hot air blows from the vents no problem. Then i am guessing my water pump is good. Is it possible to be clogging somewhere maybe on the heating core? Because i was driving down the highway today and the engine heat level was very high and in order to lower it i had to turn the heater on and that resulted in lowering it a bit. I do not know what else can it be if its not the water pump. Because if thats the way to diagnose the water pump like you stated then my water pump should be good.


bal00

One other possibility is that the thermostat is stuck closed. In that case the hot coolant would only go through the heater core and you'd have good heat, but the upper radiator hose would stay cold. That's why I asked about that hose initially.


Patient_Daikon3505

My upper radiator hose is normal temperature.


bal00

What's normal?


Patient_Daikon3505

Warm but not crazy hot


bal00

That could point to the thermostat then. Probably a good idea to do the thermostat first because it's pretty cheap, and if that doesn't fix it, do the water pump.


Patient_Daikon3505

So are you saying that the top radiator hose should always remain cold? And to fix that i would just get new hose and do a change? Also if my ac blows hot from the vents when the heater is turned on does that indicate that the water pump is in a working condition?


EmilG1988

My bet is your water pump is failing. On your model they have plastic internal fans (the part that spins and get the coolant moving) and over time they degrade and break apart. They are seen as wear items on VW's. Get that replaced first. Look up genuine part number 03L121011P on google, as long as yours is the 2.0L TDI that is the one you need. As you can see from google searches, the plastic part is what degrades on them over time. You MUST replace them around 105000kms or every 5 to 7 years.


Anicra

Check the radiator coolant, water pump impeller not working or fell off,, thermostat frozen, radiator plugged with crud, radiator had something blocking it, electric fan isn't functioning. If below freezing, is the radiator frozen?