no heat.... not the thermostat

lupin..the..3rd

Veteran Member
Joined
Feb 7, 2004
Location
USA
TDI
Passat B4 1996
1996 b4. almost no heat from the vents. a very small amount, but not much at all. coolant temperature needle is in the normal position, around 190 F. i replaced the thermostat thinking that was it..... no change.

any ideas? clogged heater core? :confused:

TIA
 

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2014 Skoda rapid elegance 1.6 cr tdi
It might be worth a shot running some coolant system flush through it but what about the heater flap? Does your car have that? I'm sure I just read about it on another post in here somewhere. Might be worth a search.
 

veedubyoo

Veteran Member
Joined
Feb 18, 2010
Location
Page, AZ
TDI
96 Passat TDI Variant
1996 b4. almost no heat from the vents. a very small amount, but not much at all. coolant temperature needle is in the normal position, around 190 F. i replaced the thermostat thinking that was it..... no change.

any ideas? clogged heater core? :confused:

TIA
Perhaps do a search...
I beleive you may be doing what I will be soon...replacing the foam on the heater doors...(of course after removing the dashboard :/)
 

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2014 Skoda rapid elegance 1.6 cr tdi
Ooh, not so pleasant. I intend to remove my dash to sort out some rattles but I'm waiting for warmer weather.
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
HVAC system's trap door foam
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Ah, the dreaded foam claims another one. I think this is France's way of getting back at Germany, as Valeo is who makes the HVAC cases for Volkswagen. :p
 

VWWV

Veteran Member
Joined
Sep 9, 2003
Location
Florida and WV
TDI
passat 96, candy white
1996 b4. almost no heat from the vents. a very small amount, but not much at all. coolant temperature needle is in the normal position, around 190 F. i replaced the thermostat thinking that was it..... no change.

any ideas? clogged heater core? :confused:

TIA
Check the blend door vacuum control (located on driver's fender near the battery) for function....it reportedly can be opened and cleaned to restore function. Check the vacuum line itself (mine was ruptured in the hard plastic part of the line). Of course, the foam of the door is probably gone. Perhaps you have noticed some black, sticky foam on your seats and your clothes and didn't know from whence it came? That foam came out of your vents. I can get some heat by turning the heat dial to red and punching the recirculation button. If I lived in the north in winter, I'd have dumped the B4 long ago because of this inherent fault. I have wondered why the European members have not commented on this fault? Perhaps the specs. for the Euro models were different?
 

r90sKirk

Veteran Member
Joined
Oct 21, 2003
Location
CedarTuckey, Michigan
TDI
All TDI's - No gassers! Luxo-Tourer = 13 Passat (hands down, the nicest car we've ever owned), Most fun = MK4 Golf
If it is the blend door issue, you should be able to press the recirculate cabin air button, and turn the fan on a higher setting and get some (more) heat out of it (for now), b/c your not taking in outside air at that point.
 

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2014 Skoda rapid elegance 1.6 cr tdi
" I have wondered why the European members have not commented on this fault? Perhaps the specs. for the Euro models were different?"

Our cars don't last long enough and we're quite apathetic about making them last that long.:D
 

VWWV

Veteran Member
Joined
Sep 9, 2003
Location
Florida and WV
TDI
passat 96, candy white
" I have wondered why the European members have not commented on this fault? Perhaps the specs. for the Euro models were different?"

Our cars don't last long enough and we're quite apathetic about making them last that long.:D
Aux Contraire! The image we have over here is that Europeans are much more conscious of value and the maintenance of their cars....ostensibly because of the cost versus income. Here we are well-known for our penchant of being a throw-away society. Having said that...it seems that more recently that we are trending to a more cost-conscious mindset.... our government officials being the exception, of course.
 

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2014 Skoda rapid elegance 1.6 cr tdi
Not in the uk though, we throw everything away wether it works or not:D Nah but seriously I haven't seen many of them of that sort of age running around. My car's a 2000 model and I think it's got 2 years tops before it's out of circulation. We get to much rust eating them up from all the salt on the roads. They're also a lot cheaper to buy second hand.
 
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saturnhacker

Veteran Member
Joined
Sep 13, 2005
Location
Pennsylvania
TDI
Passat 1996 Blue
Have you seen bits of foam coming through the vents for a while?
If so yeah the HVAC unit is probably going to have to come out
to fix that fine engineering... just did one a few weeks ago, wasnt
so bad but the dash does have to come out and the A/C system
evacuated.
 

PB_NB

Veteran Member
Joined
Nov 20, 2007
Location
Vancouver, B.C.
TDI
1999 New Beetle
I am not sure if the B4 heater core plumbing is the same as the B5 but we had a similar problem and a flush is what caused the problem. Just before the warranty ran out, the car went in for a flush and bunch of other things and then later that year we found that the heater wasn't working well, took a while to figure out the problem.

It seems that there is a bit of sludge in the cooling system. I am not sure where it is coming from but there are chunks of goo floating around and they get up the heater core piping and restrict the hot water from entering into the core or you get very little heat.

I just took both hoses off and forced water into the core in both directions and out popped the goo balls and there was heat again.

I am going to pull the engine apart to do the belts this spring and will get into the engine and clean out the coolant passages but for now, there is heat.
 
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rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
It seems that there is a bit of sludge in the cooling system. I am not sure where it is coming from but there are chunks of goo floating around and they get up the heater core piping and restrict the hot water from entering into the core or you get very little heat.
Usually caused by mixing coolants. Seldom happens if G12 or later is used exclusively.
 

PB_NB

Veteran Member
Joined
Nov 20, 2007
Location
Vancouver, B.C.
TDI
1999 New Beetle
This car has only seen G12 since new. I am not sure why it is making sludge but it is definitely there. It has a whole 80,000 km or 50,000 miles on it. And is used by my 84 year old father in law to run around town.

Perhaps the short drives are the culprit??
 

VWWV

Veteran Member
Joined
Sep 9, 2003
Location
Florida and WV
TDI
passat 96, candy white
PB NB.....you posted earlier about the "car going in for a coolant flush pre-warranty expiration with subsequent heating problems". If this was done at a dealership, chances are that the coolants were mixed? I've heard that the dealer protocol is to flush the system 4 times.....that's why they have the reputation of being four flushers:)
 
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