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1988 300E hvac -- Why me, Lord? Why me?

1K views 18 replies 11 participants last post by  Real1shepherd 
#1 · (Edited)
Haven't been here for awhile. Too busy. Too tired. But my recent discovery is so unbelievably bad I needed to share my misfortune.

A couple of years ago I bought a white 88 300E from a former BenzWorld member. I had worked on this car some years ago and knew it was a pretty nice car. When the owner wanted to unload it due to a failed transmission I declined. Too many cars, too many projects. A month later he called again to say he was going to have the car towed away. Do it I said. Come see it he said. I declined. Another month went by and he called again. Cutting to the chase I did eventually go to see the car and, for better or worse, bought it.

Cosmetically it is a very nice car. Original paint, very, very nice original palomino leather interior. 156k. Decent service history. He spent many times over the selling price to me on repairs and maintenance. But like any 30 year old car it needed attention. And, like always, it needed more attention than I expected.

The first big kick to the family jewels was discovering that, following transmission replacement, the spark plugs fouled. I knew what would be required and dove right in. Pulled the head, had all the guides replaced, a valve job done, etc. Replaced the bad camshaft (2 wasted lobes) and rocker arms with the updated parts (used) from the blown up engine from another BenzWorld member car purchase. The engine was now back together and running great. Things were looking up.

Well yesterday I discovered something that will require *a f$%&ing LOT* more attention.

Wipers were jerky. No big deal I said. I have spares I said. Blower motor inop. No big deal I said. I have spares I said. It's actually a toofer with those jobs so I wasn't worried.

Because it was handy I pulled the necessary parts from my soon-to-be-scrapped 88 300TE (smoke silver). The parts pulling went exactly as I expected. No big deal.

As evening approached I wanted to get those parts into the white 300E so I could have wipers, cabin ventilation, and get the car inspected this coming week. That would not come to pass.

Firstly I couldn't get the windshield lower trim strips off the car. They were stuck on like nobody's business and I didn't understand it. Eventually I got the driver's side off, damaging it, and discovered the problem. The windshield had been replaced and some wanker had urethaned the f$#% out of it so there was major squish out and some added as well at the bottom of the windshield. The trim strips were clipped *and* glued in place! With that info I got more aggressive on the passenger side but it simply would not budge. When the strip does finally break loose I hear a "craaack!" and sure enough I've cracked the windshield. No idea how. The clip is still riveted to the windshield frame so that didn't do it. Oh well, the install was poorly done and there was a slight wiper mark, so I can live with this setback. But things got worse. Much worse.

I remove the cowling and the wiper motor assembly (which was also glued to the windshield). Fine. Whatever.

Now it's time to remove the locked up blower motor. No big deal. Clips released, cover off, blower motor unplugged and removed. Ah, the end is near. I can hear that new blower motor running already! But it would come to pass.

As I looked into the area under the blower motor to check for any debris against the evaporator I discover something horrifying. I'm still not sure when I'll have the time or energy to deal with this.


Can't upload pics. A security token is missing? Administrators? Help!
 
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#5 ·
Every time I fill up my A/C, I feel it doesn't really do its job properly. The fan sometimes comes on and sometimes not. And after a few months it barely even cools the air down.

I guess I need to replace my AC core as well. Should have done it, when I was already in there replacing heater core. I can feel the pain.

I wish I could replace the whole heater box with a filtered one, since I am allergic to pollen.
 
#6 ·
augapfel, I'm really sorry for your experience with this car but want to thank you for the great writeup. I hope you won't be offended but your opening post cracked me up! I mean, it's such a bummer how it all went but your way of presenting it was brilliant. You should be a writer.

I assume you discovered the evaporator needs to be changed. I'm sure that day is coming on my Dad's 300TE and I should start mentally preparing now for it.
 
#9 ·
augapfel, I'm really sorry for your experience with this car but want to thank you for the great writeup. I hope you won't be offended but your opening post cracked me up! I mean, it's such a bummer how it all went but your way of presenting it was brilliant. You should be a writer.
Thanks. I was a technical writer in the automotive service industry for 12 years. So there's that...
 
#8 · (Edited)
Trying again in a new post. Nope, it's not a bad evaporator core. Nor is it rust. It's something I've never seen before.

Crap! Upload failed due to a missing security token.


Edit:
A few minutes after I posted this message I got a pop up saying that my "submission" could not be processed due to a missing security token. But the message posted. Hmmm.
 
#11 ·
I just started another thread regarding front spring replacement on this car and all the pics uploaded (YAY!) so maybe I'm back in BenzWorld good graces. You may now be able to see the true horror of what I discovered when I attempted to replace the HVAC blower motor assembly.
 

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#12 ·
Yes, the blower motor speed regulator overheated to the point that it melted a hole through the plastic HVAC box. This lovely defect means that every time it rains water pours through the hole into the cabin!

So now I have to pull the steering column and dash to replace that entire friggin' HVAC box with heater core and evaporator.

But at least I can now upload pics!
 
#15 ·
I wish. But for some reason that blower motor speed regulator heated up to the point that the whole top of the box is distorted. Why didn't the strip fuse blow??? From teh time I bought this car I realized that the blower motor was locked up and I kept the HVAC system turned off. Maybe the damage was done before I bought the car.

When my son and I strip the drivetrain out of the 90 TE 4MATIC in a few weeks that will be the end of that car. What I don't take off the body will go to the shredder. Seems like a good time to pull the column, console, dash, and HVAC box. Based on how that goes I'll decide if I want to pull the 88 apart to replace that box.
 
#16 ·
When my son and I strip the drivetrain out of the 90 TE 4MATIC in a few weeks that will be the end of that car. What I don't take off the body will go to the shredder. Seems like a good time to pull the column, console, dash, and HVAC box. Based on how that goes I'll decide if I want to pull the 88 apart to replace that box.
smart plan ! take apart the donor and see how it all goes together, rescue the parts, then R&R on the recipient vehicle should go smoothly.

me, I'd be in there with some high temp epoxy and plastic patches and whatever it took to make it work without ripping the car apart. maybe even cut the areas out of the donor box and do surgery in situ on the keeper (cut out the deformed parts and epoxy in the replacements)
 
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