I have a 2010 Volkswagen CC with a 4 cylinder turbo and on cold days it takes a long time (15 min+) for the engine to warm up where I can put the heater on. Once warmed up it stays warm. I have checked the fluid and it is good both level and quality of mix. This is only recently as before it would be warm within 5 minutes. I have brought it to the dealership and they do not know what it is. They said they would start with changing the thermostat for about $250 but not sure if that is what is wrong. Any ideas on what the problem is and is this something I can fix/ change myself. I am somewhat mechanically able.
Certainly has all the symptoms of a thermostat stuck open. They aren’t difficult to replace so I don’t understand why they are charging $250. You could certainly do this yourself.
First of all, define “cold”. If “cold” in your state means subzero, 15 minutes would be perfectly normal. Good, even. If “cold” means +40F, your T-stat may be hanging up. Ask your friends how long their cars take to heat up and that’ll be a reference of what’s normal.
A new T-stat should run around $25-$30. Assuming the project includes new coolant (a good thing), that’d be another $15 maybe. The whole job should be 1 hour shop time.
$250 is highway robbery. Find a reputable independently owned and operated shop. You do not need a dealer for this. But first be sure you have a real problem.
Assuming there are no other cooling type symptoms other than the heater. Does this car have a dashboard coolant temp guage? If so, do you notice any changes to the guage reading now compared to when the heater worked?
I think the VW dealership is saying they don’t know what it is because they simply aren’t able to guarantee with 100% certainty a replacement thermostat will fix it. That part is true, but most inde mechanics would see this as most likely a thermostat problem, and replacing it would be the most economic thing to try. Indeed, it might not fix the problem, but replacing a stat is usually easy, unlikely to cause side effects (as long as you use an OEM or equiv replacement stat), and would be the best course of first action.
If replacing the thermostat didn’t fix the problem, then it might be a plugged heater core. Or some other problem with the heating system, like the water valve is stuck shut, or the air flow doors aren’t working like they should. Is the hot water hose going through the firewall hot to the touch when the engine is warmed up? What about the return hose? Is it hot, warm, or cold? Could be a clue at least.
Me, I’d replace the stat first, and the coolant too if it hasn’t been changed out in the 2 years prior, then if this doesn’t fix the heater problem, there’s more things to try, so come back here. Best of luck.