05 Passat heater doesn't work

fenne

Active member
Joined
Sep 14, 2011
Location
Southern Idaho
TDI
02 Jetta GLS 5 speed
So my wife and I bought a used 05 Passat TDI. We have had it a couple weeks and the weather is cooling off in the mornings enough to need the heater. But it doesn't work!!! Won't blow hot air. When you turn the dial from cold to hot you can hear something in the dash move. But it only blows a little warmer but it is still cold. So where do I go from here? Also the climate control lights don"t work when the headlights are on. Thanks for the help.
 

vwztips

Veteran Member
Joined
Aug 30, 2009
Location
Greenville, SC
TDI
2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2011 Tiguan TDI/DSG 2005 Audi A4 Avant 6MQ TDI 2011 BMW X5 35d
Most likely a clogged heater core. I have had some success by removing both lines of the heater core at the firewall and back flushing with water. Have seen some pretty nasty junk come out.

I find hot water seems to help break it loose better. I have a sink I can connect my garden hose to.

For the climate control light, go to the dealer and buy the bulb. Then set the fan switch on 3 and pull the fan knob out. I use a piece of vacuum hose to slide over the old bulb and replace it with the new bulb.
 

fenne

Active member
Joined
Sep 14, 2011
Location
Southern Idaho
TDI
02 Jetta GLS 5 speed
Most likely a clogged heater core. I have had some success by removing both lines of the heater core at the firewall and back flushing with water. Have seen some pretty nasty junk come out.

I find hot water seems to help break it loose better. I have a sink I can connect my garden hose to.

For the climate control light, go to the dealer and buy the bulb. Then set the fan switch on 3 and pull the fan knob out. I use a piece of vacuum hose to slide over the old bulb and replace it with the new bulb.
I hope that it is a clogged heater core. I've read some other threads here that talk about the control box foam gasket going bad. I really don't want to tear the whole dash out. Sweet I was hoping its a bad bulb. Didn't know the knob had to be 3. Thanks a bunch.
 

vwztips

Veteran Member
Joined
Aug 30, 2009
Location
Greenville, SC
TDI
2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2011 Tiguan TDI/DSG 2005 Audi A4 Avant 6MQ TDI 2011 BMW X5 35d
Note the operative words "some success". Not all will unclog to get the full heat back. Yes I have had to replace the heater core several times. I think the balance shaft is probably easier and I don't lose as much knuckle flesh either.

The noise you hear in the dash is probably air bubbles or restricted water flow through the core.
 

fenne

Active member
Joined
Sep 14, 2011
Location
Southern Idaho
TDI
02 Jetta GLS 5 speed
I've read on other vw forums guys having luck flushing their heater core with clr. So its worth a try instead of doing the heater core replacement.
 

ericanjensen

Well-known member
Joined
Apr 18, 2010
Location
Utah
TDI
2004 Passat TDI wagon
Actually, I'm having this same problem I think. Do you hear kind of a pop when you switch from heat to cool or visa versa?

Mine was my air conditioning that wasn't working & I heard something in the dash move when I tried to switch. I took it to the repair shop & they said it was a little pin/spring located in the dash that was broken. $15 part.....$500 repair to get to it.

They went in a manually switched it from hot to cold. I can have one or the other. That was before summer & now that it's getting cold, I need my heater back. I was hoping to find a guide on how to repair it myself.
 

vwztips

Veteran Member
Joined
Aug 30, 2009
Location
Greenville, SC
TDI
2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2011 Tiguan TDI/DSG 2005 Audi A4 Avant 6MQ TDI 2011 BMW X5 35d
Are you sure it's not the control panel that has broken a tab or gear. I have seen those break for various reasons. It's easy to inspect and replace espcially if you pull the radio out and the radio cage. IIRC the control unit is not that expensive. Main tool you need is a flat blade screwdriver to pop out the cover for the controls, a T20 torx for the controls and the radio removal keys if you want to take it out (recommended along with the cage which is held in with T20 torx as well)

As for the heater core you can place your hands on the inlet and outlet hoses to check for flow. They should both be close to the same temp as the upper radiator hose (really hot). I use a laser temp sensor to check mine. If either or both are significantly cooler then most likely you have a blockage.
 

vwztips

Veteran Member
Joined
Aug 30, 2009
Location
Greenville, SC
TDI
2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2011 Tiguan TDI/DSG 2005 Audi A4 Avant 6MQ TDI 2011 BMW X5 35d
BTW, the Bentley manual is not very detailed about the removal of the dash but it does show where the key nuts and bolts are. The most annoying ones are under the dash for the support brackets.

You also have to discharge the A/C system to do this job.
 

fenne

Active member
Joined
Sep 14, 2011
Location
Southern Idaho
TDI
02 Jetta GLS 5 speed
Actually, I'm having this same problem I think. Do you hear kind of a pop when you switch from heat to cool or visa versa?

Mine was my air conditioning that wasn't working & I heard something in the dash move when I tried to switch. I took it to the repair shop & they said it was a little pin/spring located in the dash that was broken. $15 part.....$500 repair to get to it.

They went in a manually switched it from hot to cold. I can have one or the other. That was before summer & now that it's getting cold, I need my heater back. I was hoping to find a guide on how to repair it myself.
No I don't hear any pop. A/C works great. $500 bucks?! Hopefully you can invest in some DIY tools and DIY!!
 

fenne

Active member
Joined
Sep 14, 2011
Location
Southern Idaho
TDI
02 Jetta GLS 5 speed
So I flushed the heater core last nite with a little CLR. I let it sit for about 40 min. Bled the core out which seemed to take forever. But the heater felt like it was working better. I'll find out once my wife is home from working out.

vwztips, could you remove the heater core by pulling the radio out? Or is there not enough room?
 

jables

Well-known member
Joined
Dec 15, 2011
Location
new orleans
TDI
B5.5 Passat
Can someone post more detailing instructions on how to do the core flush with CLR? I have no heat and a gurgling sound...
 

jables

Well-known member
Joined
Dec 15, 2011
Location
new orleans
TDI
B5.5 Passat
Never mind, I figured it out... and I have heat now!

Dealer quoted me 1500 to replace the heater core. Crooks!
 

jables

Well-known member
Joined
Dec 15, 2011
Location
new orleans
TDI
B5.5 Passat
Well I put CLR through it using some clear vinyl hoses and a funnel. It really didnt seem clogged as gravity was enough to push the CLR through. I had it draining in a bucket and flakes of rust accumulated at the bottom.
 

auntulna

Veteran Member
Joined
Mar 13, 2005
Location
Springfield, MO
TDI
05 GLS Passat wagon, mit panzer plate
One of the two I own did this

I tried my own core flush, but little difference

Paid a local AC shop, less than $100, they expelled lots of crud, showed me

Now makes lots of heat
 

peiphil

Veteran Member
Joined
Nov 7, 2012
Location
Tignish PEI Canada
TDI
2005 passat GLS TDI and big old Dodge Cummins TDI
Ya they use muriatic acid.
Cleans out a core real good and fast!
Just dont breath it or get it on your skin.
It is also very cheap!
 

MOGolf

Top Post Dawg
Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
I must live a charmed life. I haven't seen a VW cooling system with crud in it when maintained with the VW coolant. Have these crud filled cars been victimized with other chemicals?
 

Uberhare

Veteran Member
Joined
Sep 3, 2006
Location
Ontario, Canada
TDI
Too many.
Welcome to the no heat club. My heater core is only 1 year old....Going to try a tstat. It doesn't quite reach full temp.
 

dubchef

Member
Joined
Sep 6, 2007
Location
Austin, TX
TDI
'05 Passat Wagon - CHAINLESS
We lost heat in our '05 Variant as well last month. Caused us to take the '95 Benz diesel on a long drive for xmas. (Which I feel is a much better car anyhow).

There was a horrible noise from the passenger side dash right before the heat went out. Still not sure what it was. It's going in for some loving with Mr. Plenge (RunOnBeer) on the 23rd, but I might flush the core with CLR before then. Wife made me take her car today... At 20F, it was a miserable drive to work.
 

Quest4TDI

Well-known member
Joined
Apr 22, 2005
TDI
Passat, '05, Candy White
We lost heat in our '05 Variant as well last month. Caused us to take the '95 Benz diesel on a long drive for xmas. (Which I feel is a much better car anyhow).

There was a horrible noise from the passenger side dash right before the heat went out. Still not sure what it was. It's going in for some loving with Mr. Plenge (RunOnBeer) on the 23rd, but I might flush the core with CLR before then. Wife made me take her car today... At 20F, it was a miserable drive to work.
Did you ever figure out what the problem was?

Herb
 
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