[l791020]

My 96' Passat TDI sedan is not heating. I took it in to have the A/C Compressor replaced and asked them to look at the heater while it was there and they (local european shop) said there were a few scenarios.
1. The blend door foam is gone and it just can't switch over to the heat side.
2. The heater core is bad or possibly plugged.

He did say it seemed like all the cables were connected.

This morning with the heat full blast it is slightly warm...can just barely tell a slight temperature difference...very slight.

Any suggestions?

Thanks!!

 

[grizzly]

Was it working before they touched it?

If the door foam is gone it should still switch over. The foam just seals it off. If the cable was on wrong you should feel it through the temp control knob. It's just a knob, a cable, and a lever that controls the door. If you turn the knob and feel some funny resistance, the door could be jammed.

My guess is that the door either fell off or is bent somehow. When you turn it to full heat, the door moves a little and gives some heat.

A heater core getting clogged isn't very likely. What type of coolant do you use? Your coolant should be pink. If it's brownish or greyish, then it's been mixed or contaminated. VW coolant can't be mixed. The Euro shop should fix it if they mixed the coolant. If the contamination is really bad, it could cause some heavy deposits but I don't think this will clog the entire heater core.

 

[chittychittybangbang]

2nd the broken or malfunctioning door, maybe the cable or lever is broken. It's not the thermostat since it gets coolant after the heater core. Is your car not warming up??? The heater core could be coated with junk on the inside which would prevent much heat exchange but I can't believe that it would totally prevent any heat.

Only other thing I can think of is if the coolant hoses were bypassed. I can't see anyone doing this unless they lived in Hawaii and it would be easily noticeable.

 

[l791020]

The shop did not really change anything with the heating problem, they just did a quick trouble shoot...they didn't do anything with the coolant either; I'm not sure what the color is but I will look tomorrow and get back. When I switch from cool to heat is feels normal and switches over smoothly.

A bit more history on the car...I bought it 3 months ago from the first owner who had it one year in Virginia and then moved to Florida where it stayed the rest of it's life until I brought it to Tennessee.

I really doubt the previous owner ever used the heat once he left Virginia, and I assume he didn't even know it didn't work.

Also the car has 93,000 origional miles.

I have never noticed any of the foam pieces anywhere in the car like I have read others have experienced.

What all will be involved to see if the blend door is not functioning properly?

I would like to repair this myself due to the pending charges and also just having to have the A/C Compressor replaced (the AC Compressor clutch fell off the old one).

I have a bentley manual that will be here today (monday 22nd).

Thanks!

 

[BillK]

The manual has plenty of pics, I think the blend door is just a door that moves back and forth which lets air into or blocks air away from the heatercore.

 

[Hazady]

I think I saw this posted elsewhere, someone said it was the foam seal around the door. If you never saw any foam bits fall out then it's possible the door is broken, if the foam bits blew out then it's probably the foam. The strange thing is that the foam should get blown out when you use the blower.

 

[tumpee]

Problem with 1996 Passat heater

I bought my Passat used and the heater worked well until I changed the antifreeze from pink to green. I don't know if that caused the problem or something else went wrong at about the same time. I do see a lot of flat foam trapped in the vents. I was told by an experienced mechanic that it took about 8 hours work to disassemble the heater and clean out the foam so the heater would work again. I'm not sure that this is the easiest way to accomplish this. I flushed the heater core with CLR and it came out clean. My door flapper seems to be working fine. Someone give me a workable answer to this problem that won't take all day or cost a fortune. I'm familiar with almost all other 96 TDI problems except this one.

 

[Vent5]

I bought my Passat used and the heater worked well until I changed the antifreeze from pink to green. I don't know if that caused the problem or something else went wrong at about the same time. I do see a lot of flat foam trapped in the vents. I was told by an experienced mechanic that it took about 8 hours work to disassemble the heater and clean out the foam so the heater would work again. I'm not sure that this is the easiest way to accomplish this. I flushed the heater core with CLR and it came out clean. My door flapper seems to be working fine. Someone give me a workable answer to this problem that won't take all day or cost a fortune. I'm familiar with almost all other 96 TDI problems except this one.

Yep, if you see foam then it's definitely the problem. No way to fix it without replacing the foam. 8 hours work is way too much for a mechanic but it might take you 8 hours work. It requires removal of the lower center console, the part with the knobs. The mechanic probably thought 8 hours was to remove the entire dashboard and heater core. Tell him that you just need to replace the foam on the blend door.

PS, if you are going to use green coolant make sure you flushed all of the old coolant out. They can't be mixed.

 

[chittychittybangbang]

I bought my Passat used and the heater worked well until I changed the antifreeze from pink to green. I don't know if that caused the problem or something else went wrong at about the same time. I do see a lot of flat foam trapped in the vents. I was told by an experienced mechanic that it took about 8 hours work to disassemble the heater and clean out the foam so the heater would work again. I'm not sure that this is the easiest way to accomplish this. I flushed the heater core with CLR and it came out clean. My door flapper seems to be working fine. Someone give me a workable answer to this problem that won't take all day or cost a fortune. I'm familiar with almost all other 96 TDI problems except this one.

Many people have had this issue. You have to repair the foam on the flapper. It won't work well until it's fixed since you see foam blowing out. That confirms the problem and solution. I've never done the repair but from what I hear, you have to remove the lower dash to get access. I think that you may be able to snake an arm up there, don't know for sure. 8 hours of labor seems excessive but I've never done this one so I can't say for sure.

And G12 G12+ coolant is best for VW engines since it's phosphate free forumla prevents scale and corrosion. If you decide to switch it out, make sure to throughly flush out the green stuff.

 

[grizzly]

The way to save money is to buy a bentley manual and do it yourself. No easy and quick fix other than taking it to a mechanic, sorry.