Stumped on my no heat

Beerbaron666

Active member
Joined
Dec 31, 2017
Location
Vancouver bc
TDI
2000 Jetta
Hi there, I've been lurking on here since I got my TDI just over a year ago and found a lot of useful info from the members here. I come across a problem that I just can't seem to figure out and was hoping someone could give me an idea that I haven't tried yet. I have a 2005 Jetta with no heat and since the Canadian winter is kicking in it's getting pretty damn cold lol. I just replaced the timing belt and water pump, new thermostat and housing, I've checked the blend doors and they are moving and the foam is still good, I've flushed the heater core and water flows through it fine , I've pulled off various hoses and flushed them and everything seems to flow fine. The car gets up up to operating temp and holds fine but I just can't seem to get any heat at all, I'm stumped here I've done everything I can think of and hoping someone here can point me in a direction I haven't thought of yet. Thanks in advance for any help.
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
The dash gauge for temperature isn't known to be the most accurate device known to mankind. I'd look to utilize a thermal gun (open up coolant overflow tank and measure) or connect up VCDS or something like Scangauge or Ultragauge which can also read the actual engine temperature as is conveyed to the ECU. You can check the upper and lower radiator hoses to see if coolant is circulating properly: lower will cooler; top will be warmer/hotter. Also should see coolant circulating in the coolant overflow bottle.

It's not all that uncommon for new thermostats to be bad: it's one reason why one should always test them to check proper operation before installation.

Trapped air will tend to hinder coolant circulation.

Of course, and I figure you're already aware of this, but it needs to be said anyway, diesels will struggle to warm up when temps are cold and the engines aren't put under a load.
 

Beerbaron666

Active member
Joined
Dec 31, 2017
Location
Vancouver bc
TDI
2000 Jetta
The dash gauge for temperature isn't known to be the most accurate device known to mankind. I'd look to utilize a thermal gun (open up coolant overflow tank and measure) or connect up VCDS or something like Scangauge or Ultragauge which can also read the actual engine temperature as is conveyed to the ECU. You can check the upper and lower radiator hoses to see if coolant is circulating properly: lower will cooler; top will be warmer/hotter. Also should see coolant circulating in the coolant overflow bottle.

It's not all that uncommon for new thermostats to be bad: it's one reason why one should always test them to check proper operation before installation.

Trapped air will tend to hinder coolant circulation.

Of course, and I figure you're already aware of this, but it needs to be said anyway, diesels will struggle to warm up when temps are cold and the engines aren't put under a load.
Should I see the coolant recirculating when the engine is hot or cold? I'll plug into VCDS and check the temp just to make sure too. I'd be pretty pissed if I put in a crap thermostat lol
 
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