Blend Door Fixed!

[Moto-Mojo]

Originally Posted by camguynj

For those that did this fix what are your thoughts on using a 1/4” round saw attached to a 10” flexible drill bit to make the cut?

I'm not the world's greatest mechanic but I will be finishing this hack tomorrow - - DAY THREE! I found NOTHING about this easy. I will think about the saw question because even though the hot knife worked pretty well, you do have to be careful around the heater core. And the uneven surfaces plus cramped space might make the saw more difficult. I nicked the fins but hopefully didn't pierce it.

Full report mañana. I'm beat!

[ariZona28]

Originally Posted by Moto-Mojo

I'm not the world's greatest mechanic but I will be finishing this hack tomorrow - - DAY THREE! I found NOTHING about this easy. I will think about the saw question because even though the hot knife worked pretty well, you do have to be careful around the heater core. And the uneven surfaces plus cramped space might make the saw more difficult. I nicked the fins but hopefully didn't pierce it.

Full report mañana. I'm beat!

Did you remove your driver's seat? No way I could do this repair with the seat in place. I give you credit for undertaking this PITA task. Don't feel bad, I often turn a 3 hour job into a 3 day ordeal. I don't even get mad anymore. (Well, not AS mad).

[Jeff_SS]

Originally Posted by Moto-Mojo

I'm not the world's greatest mechanic but I will be finishing this hack tomorrow - - DAY THREE! I found NOTHING about this easy. I will think about the saw question because even though the hot knife worked pretty well, you do have to be careful around the heater core. And the uneven surfaces plus cramped space might make the saw more difficult. I nicked the fins but hopefully didn't pierce it.

Full report mañana. I'm beat!

Looking forward to the full report. Every time someone else does this and reports back with good results it's encouraging. I need to do this soon when I can get a second set of eyes/hands to help me.

Originally Posted by ariZona28

Did you remove your driver's seat? No way I could do this repair with the seat in place.

I'm definitely going to disconnect my battery and remove the drivers seat when I go to do this.

[joekono]

Originally Posted by Jeff_SS

Looking forward to the full report. Every time someone else does this and reports back with good results it's encouraging. I need to do this soon when I can get a second set of eyes/hands to help me.



I'm definitely going to disconnect my battery and remove the drivers seat when I go to do this.

Moto-Mojo, good luck. Man I'm scared sh*t of this issue and I'M MECHANICAL. Just to reiterate, even though I have most of the threads related to the Blend Door issue, does the door reset, knob position hack or blend door motor disconnect a full proof way of get rid of this issue? GM really needs to pay to have this fixed. Oh, I'll be happy to pay for the door.

[Moto-Mojo]

Welp, roughly 14 hours of total grind time, and it's done. I took many breaks. Halle-freakin-lujah! I took a pic out in in the dark garage this morning but I moved. Blurry. So I just finished instead. I've seen worse looking hacks online. Mine wasn't too bad looking.

I wished there was another way. But it was pushing $4K as you all know at the dealer.

First, the OP's write-up here gives you the gist of the operation. Good place to start. Also, "737Mechanic" who hangs here and has a couple great videos was what I used too. However... there were a couple of things I either wanted, or had to do, differently. And a couple of my own hacks. I can only add a little to what's already been said. Ok, maybe more than a little.

RULE #1: This is an absolute exercise in patience! If you have little (like me) you will need to learn to be more Zen-like. Otherwise, pay the man! I found every facet of this to be difficult. Removing and replacing the seat might be the most straight forward procedure of the entire fix. That's mostly because the rest is something that was never meant to be done in the first place.

RULE #2: The hot knife seems the best route. I think even small saws won't get past the uneven surfaces. BUY A GOOD ONE. My $18.00 Chinese special crapped out in 5 minutes. Luckily, I had an old soldering pencil and the threaded blade adapters fit it. Saved me.

Removing Your Cutout "Access Door": I saw only one video where there was a GREAT tip on getting the hacked door out -Pull Down and outward. Even though this is still hard, you might break little pieces of it. I did. Be careful. I found using a 5/8 socket as a wedge to support the screwdriver helped pry it out. The socket allowed for more screwdriver travel. (sorry, no pic) It takes enough force to get past the remelted-back-together cuts apart that it can snap bits off. It appears you can just pry it straight out. But the "channels" discussed by the OP and 737Mechanic are holding it in place. Down and then outward. And Up and In when reinstalling your beautifully hacked door.

Metal Blend Door: I used an aluminum blend door from BlendDoor USA suggested here. (about $90.00) In my opinion it had a couple of minor issues. One, it didn't seem to fit perfectly. It swung mostly free but seemed to hang ever so slightly in spots. Maybe just jagged edges on the opening? I figured as 'torquey' as that actuator motor is, it would still work. And it did. The other minor issue is it was fairly heavy compared to the POS plastic door. It made it more difficult to keep stabbed on the rear pilot hole bore. And that bore is very shallow. It's quite the operation to get the new door in place, (through the jagged, melted hole you made) keep it there, all while trying to reinstall the HACKED piece of airbox thing you cut out earlier. Extra dose of Zen here...

HACK TIP: If you use the hot knife, you’re bound to have some minor collateral damage. Mine was the actuator motor mounts. It's mounted by two mount bolts and one plastic positioning pin/post. The side of the knife melted the pin off. I ground it down to a nub, drilled a small hole, made a spacer to space it to the height of the other mounting standoffs and used a 3rd screw. Worked really well. (again, sorry no pic)

HACK TIP: There are various notes and opinions about whether or not to remove the Body Control Module. You’ll see it when in there. It does interfere quite a bit with the convoluted bends of the lower heat duct. I found that all while working on the door hack, actuator motor, etc., it was easier to remove the BCM. I did fish the duct out with it in place. As it turned out, I found that leaving it in place was better to replace the duct piece. However, there is little room. So I ground/sanded down the sharp flanged edges where the two-piece duct is joined and actually put a little grease on the edges. After an hour w/o doing this, this made it slip right in. It’s a colossal PIA otherwise.

Sorry for the windy post. I hope this and all the other sources help. You WILL need them to go along with your newfound patience! Lastly, it all worked out. I might need an AC service. It was getting weak before the door snapped. It’s also possible the door and motor might need calibrating with a scan tool. I can hear the motor sweep the door and get plenty of heat and cool air. I’ll find out how cold it is when it’s hotter out. Best of luck!

[GrandAmGT]

So is the blend door failure rate 100 percent? In other words, are all of us going to have to fix this at some point?

[Moto-Mojo]

I don't know about 100% but it sounds close, eventually.

Did anyone get better temps - hot and cold with a door/actuator scan calibration? It's hotter than hell but not as cold as I think it should be. As mentioned, my AC just might need routine servicing. But before this new door, it was ONE temp only. Luke warm.

[camguynj]

Originally Posted by Moto-Mojo

I don't know about 100% but it sounds close, eventually.

Did anyone get better temps - hot and cold with a door/actuator scan calibration? It's hotter than hell but not as cold as I think it should be. As mentioned, my AC just might need routine servicing. But before this new door, it was ONE temp only. Luke warm.

What position was your Temp dial at when you started the fix? FWIW I read if you don’t re- calibrate the actuator then it won’t go past it’s last position when you reattach it.

[Moto-Mojo]

Originally Posted by camguynj

What position was your Temp dial at when you started the fix? FWIW I read if you don’t re- calibrate the actuator then it won’t go past it’s last position when you reattach it.

Well, I thought I put it in the COLD position. (matching the dial) After sleeping on it, I might have had it reversed. So I disconnected the battery per one suggestion. It cycles thru hot and cold fine. I can hear it. It's just that it's more hotter than more colder!

I'm coming to the conclusion that a calibration error, baked into the ECM - cycling too far, too long, etc., is what's killing these doors. But since Chevy ain't talking, who knows?

[Joe.G]

I am thinking about just unhooking mine, I don't drive when its cool. I guess if worse came to worse I could crawl under and re hook it if I needed heat for some reason.

[Moto-Mojo]

Originally Posted by Joe.G

I am thinking about just unhooking mine, I don't drive when its cool. I guess if worse came to worse I could crawl under and re hook it if I needed heat for some reason.

The actuator motor unhooks pretty easily. QD wire connector, if I recall. (no need to disconnect on the hack) If you can get past that damn duct!

[joekono]

I am thinking about just unhooking mine, I don't drive when its cool. I guess if worse came to worse I could crawl under and re hook it if I needed heat for some reason.[/QUOTE]

Good idea Joe.G. The more I think about that fix, the more I'm thinking I should disconnect the motor. I have a vert, rarely drive her in the cold(garage queen) and when the salt hits the roads, she gets put up on Road Rams for the winter so it does make since rather than worry. Luckily, in the 4 years I've had her, I only had one bad winter. I'm at 56668 now so I WILL worry a long time. GM really should pay for this fix.

[Moto-Mojo]

Update: I'm still getting a little warmer air on the pass side than driver. The metal blend door came with glued foam on both sides of the door. Much cooler in N CA now so I'll probably bite the bullet and have it scan-calibrated come spring. I'm thinking that foam might also need to be compressed over time where it meets each side. Might be allowing hot/cold air to creep in thru a small gap. I'll keep ya's posted.

[camguynj]

Originally Posted by Moto-Mojo

Metal Blend Door: I used an aluminum blend door from BlendDoor USA suggested here. (about $90.00) In my opinion it had a couple of minor issues. One, it didn't seem to fit perfectly. It swung mostly free but seemed to hang ever so slightly in spots. Maybe just jagged edges on the opening? I figured as 'torquey' as that actuator motor is, it would still work. And it did. The other minor issue is it was fairly heavy compared to the POS plastic door. It made it more difficult to keep stabbed on the rear pilot hole bore. And that bore is very shallow. It's quite the operation to get the new door in place, (through the jagged, melted hole you made) keep it there, all while trying to reinstall the HACKED piece of airbox thing you cut out earlier. Extra dose of Zen here...

You would think the foam covering would provide a better seal against the heater and evap cores than just the plastic blend door? Could you tell if the aluminum door was flat on both sides or did it have the pattern grooves on the evap core side and just the raised humps on the heater core side?