About to replace my heater core. Looking for advice and that blend door foam

I'm about to attempt the daunting task of replacing my heater core in my '98 Jetta. The smell of coolant in the car is just too much to handle.

After reading up in my Bentley manual and watching 2 videos, I can tell this is going to suck.

Any advice or hints or tips to make this easier. Any links to a good TDIforum tutorial or online site that I might have not seen yet?

I noticed in all the videos, the guys removed the steering wheel. Wouldn't it just be easier to remove the whole steering shaft? I did that when I replaced an ignition problem, and it was only a few bolts. The process of removing the steering wheel seemed longer than just removing the shaft+wheel.

Also, I'm looking for who sells that foam that is applied to the blend doors. I can tell my foam must be trashed, because it has been flying out of the vent registers for years now. So does anyone know where to by new blend door seal foam?

I used bitumen tape to tape over the blend doors. Definitely won't come off again!

You can remove the whole steering column assembly if you like, it certainly isn't hard. Just make sure the orientation of the wheel/shaft stays lcoked straight up so that the clockspring doesn't get damaged.

Just take your time and use the opportunity to clean and repair anything in there as it is a big job.

genscripter said:

Also, I'm looking for who sells that foam that is applied to the blend doors. I can tell my foam must be trashed, because it has been flying out of the vent registers for years now. So does anyone know where to by new blend door seal foam?

Click to expand...

I've used the foil ducting tape from Lowe's a number of times, and used adhesive backed foam once, as well. Both work just as well as the other, but there is a sound difference between the two. The ducting tape gives the doors a much more "tinny" type sound to them when you're adjusting them. I would consider the foil tape easier to use because you can stack layers of it to make sure you cover any voids. The adhesive foam needs to be cut to the right size and separate pieces need to butt up against each other.



One note here, though, do not use duck tape. I did that once and never again... The heat in the car always smells like hot duck tape.

foil tape...I used the foam adhesive sheet stuff and some of it didn't stick too well...

also, check the cable mounting...one of mine had broke and the door never fully operated...used some JB weld putty to hold the cable sheathing and now everything functions as it should..

Thanks for all the suggestions. Very smart stuff.

Since i have blend door issues, and my blower motor is squeeking, I'm going to tear down the whole Jetta dash. At almost 300K miles, I guess i'm overdue for an internal overhaul. Just really stupid the HC is placed so far in. Bummer the engineers designed it this way.

I was looking at the setup, and if they have an access door under the ECU, then this would be a much easier job. If I didn't have to do the whole blower motor + blend door fixes, then I'd be tempted to just use a small cutting wheel and make an access panel on the metal under the ECU. Is there any history of guys making their own access doors to make the HC easier to extract? If yes, then I'm tempted to make an access panel once I have all the dash out, just so that I don't have to do this all over again if the HC breaks at 600,000 miles. I'd rather spend an hour now making it accessible rather than go thru this all over again.

I have another question: A few years ago, my heater wouldn't blow a lot of hot air. I can tell the HC was getting coolant, but when I turned it to "hot" on the climate control, it would blow moderately warm at best. Since I'm in California, it never gets cold, so I never really cared. But now that I' have the dash all apart, what should I look for to fix this no-hot air issue? My VW friend said it was likely the blend doors not working due to that loose foam sealant blocking the movement of the doors, but I just wanted to ask the forum anyway.

Thanks!

a QUALITY HVAC foil backed adhesive tape, OR spray contact adhesive and a quality synthetic foam. The foam that they used back in the 90's has NOTHING on the stuff we use today. I would opt for BOTH just incase the foam fails 10 years later, but it wont. Foam will stop the noise BIG time.

I covered the blend doors in my B3 with cork using contact adhesive, it stank for at least 6 months after, but now is good, just need to find a solution for the outer air vents because the foam has gone from them

I used adhesive backed felt and then covered that with some aluminum hvac tape.


Steve

My friend sent me this link: http://forums.tdiclub.com/showthread.php?t=233174

I have the dash, instrument panel, a most of the harness taken care off. I'm moving on to that metal armature that is directly behind the dash. I cannot believe the shop manual says this is a 6 hours job. Half my freaking car is disassembled and I'm not even close to done!

I want to find the engineer that designed this, and strangle him.

BTW, I did pull the whole steering wheel by removing the u-joint locking bolt, instead of doing the whole steering disassembly. It was MUCH faster. I'd recommend that to anyone with the misfortune of having to do all this for the heater core. I'm going to replace the blower motor while I'm doing the HC and fixing the vent foam. And the radio and speakers while it's apart.

Well, I got that darn heater core out. That was horrible.

While it was all apart, I cleaned up the heater box. Put in new HVAC tape on the valves. Replaced the blower motor. Replaced the foam seal between the heater box components. Wiped out all the coolant/water that pooled in the box and car.

I also got rid of all that foam wrap for the wires. It was crumbling all over the dash. I fixed it with plastic wire shielding, and it looks a lot better. Also, I cleaned up the connectors with electrical connector spray, and I applied anti-corrosion grease on all the connectors so they'll be easier to separate in the future.

While reinstalling the dash, now my instrument cluster doesn't work. Any ideas?

If anyone is reading this in the future, and they are contemplating doing this heater core replacement job, just go and buy a new car. It's not worth all this effort.