Long time to get heat

[AudiNike12]

This is the first time it's really cold here since I bought the car so I haven't really noticed it before. It took around 30min to get some heat in the car and the fan that blows up against the windshield never really get fully warm. This can't be normal right. Could the thermostat be stuck open?

[m_haiser]

how cold? your car may not be reaching full temp if its at or below freezing. when my car was in Alaska I had to put a piece of cardboard in front of the radiator for the car to warm up. if you have access to vagcom you can check coolant temps

[AudiNike12]

-10 to -15C. I did check the coolant temp sensor in VCDS. Should I check if it reaches normal temp(90C)? How long should it take to reach that?

So it might be nothing wrong?

[m_haiser]

yes make sure it reaches normal operating temp. shouldn't take more than 10 or 15 minutes when driving. if it doesn't warm up. try dropping something in front of the radiator to block the cold air running across it and see if it gets to (and not above) temp then

[ShelbyM3]

I have the same symptoms, but for me it’s my heater core.


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[m_haiser]

yeah could be that too

[AudiNike12]

Shouldn't my heater core work if I get heat?

[brokenwrench]

It's common on C5's for the heater core to get blocked up with crud from the many years of use. There are threads on here with people flushing/replacing their heater cores, not too bad either way as I can tell.

Just make sure you check your coolant temps in VCDS to make sure the t-stat isn't the problem.

[AudiNike12]

Ok, how do I know by looking at the coolant temps that the thermostat is the problem? How do I determine that?

[m_haiser]

if its stuck open you wont quite reach operating temp because its not holding back the flow of coolant until it reaches temp. rather it would allow it to flow through the radiator which lowers the temp

[AudiNike12]

Ok, I'll take a drive tomorrow with my VCDS and check it out

[rollerton]

1- You don't really mention if the time it takes to warm the engine is at idle or while driving? In cold weather these engines do not warm up well while idling. Even at not super cold temps it can take 15-20 minutes of idling to get an engine near 'warm' on the gauge. And you're in Sweden and you car is A 2.4- is it a regular petrol engine or Diesel? In the US we don't have those, so it's hard to keep track of what everywhere else got. If it's a diesel then obviously it's a going to be a COLD engine.

If the engine never really gets to operating temp, or it does but the temp fluctuates fairly noticeably on the gauge, then very likely you have a stuck open thermostat (like I do!). But even if the temp is around the COLD line on the gauge you should have decent consistent heat.

If you can hold the RPM up a little, (or better yet drive it keeping the RPM's up to heat it up faster), and you get heat while the RPM's are up; but the the air vents cool off fairly quickly then it's very likely you have air in the heater core or it's blocked as mentioned before. The B5/B5.5 VW Passat has A LOT of trouble with this; every passat I have ever known has had this problem to some extent.
You can google 'VW Passat no heat" and find an entire world of solutions or procedures to deal with this. It's very nearly exactly the same setup and dealing with it is exactly the same.

[AudiNike12]

It was at idle and it's a regular petrol engine. If I recall correctly, and I'm not sure about this, I don't think I've ever seen it reach operating temp(90C). Or it has taken a very long time. Never really paid much attention to it though. Which makes me think it's the thermostat. My timing belt service is due and you change the thermostat at the same time

But I shall see tomorrow

[AudiNike12]

So...I let the car idle for 15min to warm it up a little, then took it for a 35min drive. The engine temp when I came back, 65C. It never crossed 70C on the gauge while driving and the temp even dropped a little while driving. Then it went up a bit again. Then dropped a little. Gotta be the thermostat being stuck open no?

[m_haiser]

certainly sounds like a thermostat

[AudiNike12]

Guess I'll change it and see if it helps. Will have to wait a little while though until I change the timing belt, waterpump etc.

[ShelbyM3]

Yeah, that sounds thermostat to me, too.


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[AudiNike12]

I also have low oil temp but that has to be because the engine is not warm enough to heat it up properly because of the thermostat being open no?

[m_haiser]

very possibly yes

[AudiNike12]

Ok

[das_boosthead]

Mine did this and replacing the thermostat resolved the issue.

[AudiNike12]

I forgot about this lol But yes, it was the thermostat. Thanks :D

[m_haiser]

glad you got it sorted!

[AudiNike12]

me too. it's nice and warm now