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.
 

turbobrick240

Top Post Dawg
Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
Maybe air locked? I'd try parking the car on a very steep uphill incline to encourage any trapped air to find its way out. Temporarily disconnecting the hose to the expansion tank (with the front end raised) might also help to evacuate any air.
 

Beerbaron666

Active member
Joined
Dec 31, 2017
Location
Vancouver bc
TDI
2000 Jetta
Maybe air locked? I'd try parking the car on a very steep uphill incline to encourage any trapped air to find its way out. Temporarily disconnecting the hose to the expansion tank (with the front end raised) might also help to evacuate any air.
Thanks I'll give it a go and see what happens , should I see coolant recirculating when the engine is cold or (I'm guessing) hot?
 

scooperhsd

Top Post Dawg
Joined
Aug 19, 2003
Location
Kansas City KS
TDI
NB, 2000, RED(5 Speed conversion) 2015 Golf SE
#1 - The earlier TDIs don't warm much - if you want interior heat, observe the following
A - unless you're using the defrost, turn on the Recirc
B - DON'T turn the fan above 2-3 - you can literally cool off the engine in winter doing this
C - this is one time the automatics have an advantage over the manuals - the same coolant also cools the transmission
D - two words (if you car has them) -"Electric seats" - don't set them too high or you can burn your backside. But they help greatly
E - If you're one of those people who take your coat off in the car, expecting it to keep you warm - get out of that habit.
F - TDIs can actually COOL OFF at stop signs / lights
G - TDIs don't warm very well unless you're working them - the harder the better. A good suburban / highway helps a great deal. Corollary to this - they don't warm up very much at idle. It will stop running rough like a truck after a minute or so, but not much beyond that. starting in cold weather, an experianced TDI driver will start his car, get belted in / other things prior to moving, then take off at a moderate pace.
H - Consider warmer clothing for the driver and blankets for the back seats / FS passenger

Hope this post helps.
 

alame

Active member
Joined
Nov 29, 2017
Location
Mission BC
TDI
2005 Passat
how much water is in the rad and can you see it circulating when the engine is running ((hot) meaning the thermostat is open ?
 

Beerbaron666

Active member
Joined
Dec 31, 2017
Location
Vancouver bc
TDI
2000 Jetta
how much water is in the rad and can you see it circulating when the engine is running ((hot) meaning the thermostat is open ?
I havent really looked to closely at the flow, but the upper rad hose gets hot and the lower is cold so to me i would guess the thermostat would be working. the system pressurizes all the hoses get warm or hot except the one heater core hose only gets slightly warm.
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Have you ever gotten heat output from your cabin heater (heater core)?

There are two heater core hoses. You cay that one gets only slightly warm, but what about the other one? If one is hot and the other not I suppose it's possible that the heater core is plugged up.
 

Beerbaron666

Active member
Joined
Dec 31, 2017
Location
Vancouver bc
TDI
2000 Jetta
Have you ever gotten heat output from your cabin heater (heater core)?

There are two heater core hoses. You cay that one gets only slightly warm, but what about the other one? If one is hot and the other not I suppose it's possible that the heater core is plugged up.
The heater worked fine when i got the car just over a year ago, the one hose that goes to the hard line that runs back for the oil cooler and back to the block get warm but the other that comes off the side of the engine is warm close to the engine but is cold closer to the heater core. I just took the car for a drive to get it as warm as i could and pulled off a couple of the smaller hoses and they seem to "pulse" they dont seem to have a steady flow. the warmest i could get the car was 87 (188.7) those are the numbers from VCDS, the car has a 190 thermostat, could it be not opening fully at that temp and limit the flow?
 

turbobrick240

Top Post Dawg
Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
Yeah, that sounds like classic air locking. I forgot to mention that you should let the car idle for about 20 minutes while parked on the uphill slope with the expansion hose unhooked.
 
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Beerbaron666

Active member
Joined
Dec 31, 2017
Location
Vancouver bc
TDI
2000 Jetta
Yeah, that sounds like classic air locking. I forgot to mention that you should let the car idle for about 20 minutes while parked on the uphill slope with the expansion hose unhooked.
I'm going to give it a try tomorrow and see how it goes, thanks for the help
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
1st step, get a thermometer, inferred or probe.
Start taking readings from vents, heater core lines under the hood, lower and upper hose when it’s to "temp" VW temp gauges on TDI's are very "vague" TDI's temps are not constant like a gas engine, so VW programed them to be "to temp" when it could be 95*F to 120* Depending on eh model. Not sure about yours exactly but this is typical on VW.
Until you know exactly what temp what hoses are doing what, your wasting time and parts. Get some data. If your heater core is getting the same temp in and out and no hot air, well then your core is completely clogged to the point where no heat exchange is happening (assuming your vents and blower and filter are working properly. An Air lock will be obvious. Must TDI's do not ever put out decent heat.
How did you and what did you use to flush the system? What did it look like when you did it? Just running water in a dirty system does not make it better.
 

JB05

Top Post Dawg
Joined
Oct 20, 2005
Location
Il.USA
TDI
Golf,2005,anthracite blue
A how-to thread somewhere here mentions using a miti-vac connected to the upper return hose on the reservoir while pouring in the G13 coolant. I found this out after I had changed my t-stat about a month ago and suspect I have an air lock. I do get good cabin heat, but my engine runs hotter than it has in the past.
Post #7 http://forums.tdiclub.com/showthread.php?t=264619&highlight=draining+coolant
 
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Beerbaron666

Active member
Joined
Dec 31, 2017
Location
Vancouver bc
TDI
2000 Jetta
1st step, get a thermometer, inferred or probe.
Start taking readings from vents, heater core lines under the hood, lower and upper hose when it’s to "temp" VW temp gauges on TDI's are very "vague" TDI's temps are not constant like a gas engine, so VW programed them to be "to temp" when it could be 95*F to 120* Depending on eh model. Not sure about yours exactly but this is typical on VW.
Until you know exactly what temp what hoses are doing what, your wasting time and parts. Get some data. If your heater core is getting the same temp in and out and no hot air, well then your core is completely clogged to the point where no heat exchange is happening (assuming your vents and blower and filter are working properly. An Air lock will be obvious. Must TDI's do not ever put out decent heat.
How did you and what did you use to flush the system? What did it look like when you did it? Just running water in a dirty system does not make it better.
Ya I just used a water hose to see if water would flow through the heater core, which it did) and the water didn't look all nasty or anything it didn't take long for it to look clean.
I cant seem to get a steady flow on the return hose into the reservior, coolant will come out but it seems to be purging. I tried purging the air for an hour with only bursts of water here and there
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Ugh, sorry, just reread (first post) in which you mentioned the flow through the heater core was good.

For now you might look to block off your grill to help maintain what heat you do have.

Need to physically check temps. If not trapped air (proper coolant level) and there's good circulation then that only leaves the thermostat and water pump.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Sounds like maybe the heat control is not engaging. When you slide it from cold to hot does it feel right? Never had to mess with my heat controls, but something in there tells the coolant to flow thru the heater core when turned to warm.
 

pdq import repair

Veteran Member
Joined
Nov 6, 2016
Location
idaho
TDI
09 Jetta
Find a good long hill, or a highway run long enough to get the temps as high as you can. Check to make sure the lower radiator hose is hot, or at least warming. If it is, the thermostat has opened. See what temp that is and compare to the factory thermostat setting. If it is too cold, the thermostat may have failed or stuck partly open. Either one of those will starve you for heat in the cabin on a cold day. Also look to see if the coolant is circulating into the reservoir tank when the engine is cooler, before the thermostat opens. If there is no flow from the small hose on the top, your water pump might be stripped.

If all of this feels normal then pop off the lower cover of the dash on the left side and you can see the heater core hoses on the heater assembly. There is a cover you can pop off the core and feel it too. It should be too hot to touch with the gauge reading midway. Not uncommon for cores to plug, mine did and the only heat I had was from the electric grid.
 

sisyphus

Veteran Member
Joined
Dec 8, 2008
Location
Appleton, Maine
TDI
99.5, '01 A4 Jetta sedans, 5 sp box, Hamman mod, Joey mod, Bilsteins, 2.00" lift
I'm surprised nobody's bought up the blend door thing.
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Just to refresh, here's what the OP stated in post #1:

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 al.
 

joetdi

Veteran Member
Joined
Mar 8, 2008
Location
Midwest
TDI
2-2002 Jettas W/Auto
The reason I asked about passengers is I wanted to know if they complained about cold feet. Did you check and see if the cover for the pollen filter has fallen out.
 

CoolAirVw

Vendor
Joined
Nov 9, 2005
Location
Kansas City Missouri
TDI
Jetta
I've checked the blend doors and they are moving and the foam is still good,
You said, "the foam is still good". How did you check that?

Also just because water flows through the heater core does't mean its ok. IT could be bypassing large portions of the coils and still look like it was flowing ok.
 

Beerbaron666

Active member
Joined
Dec 31, 2017
Location
Vancouver bc
TDI
2000 Jetta
First thanks everyone for the responses and I'll try and answer as much as I can
I checked the blend door by removing the center of the dash and opening the box up and they looked to be in good shape, I left the heater controls hooked up and everything seemed to o move as it should.
I just replaced the water pump and thermostat just before Christmas so I'm hoping it's not a faulty water pump.
I did run water through the heater core and true it doesn't mean it's not plugged, I really hope it's not cause I do not want to tackle that job but I'm starting to think it is.
A question on top of all my other questions lol is there any sort of diverter valve on the heater core or anything mechanical or electric that it could be?
Question two is there anyway to unclog the heater core if it is plugged?
I've tackled a lot of stuff in the auto world but this has me stumped
I'm going to try a couple more tricks to "bleed" the system and hope for the best but please keep the ideas coming at this point I'm willing to try just about anything
Thanks again for all the help! Cheers
 

turbobrick240

Top Post Dawg
Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
Warm the car up, find a big hill to climb , and pretend it's Pikes Peak :D. Safely, of course. If a couple runs like that doesn't revive the heat, I'd suspect a blocked heater core. There are flush treatments (usually acid) for blocked cores, but I'd just replace a bad one.
 
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