Replaced my blower fan and now I'm getting serious!!

[Torchred96]

No air volume, changed the fan to an ac delco from ebay...marginal improvement.

With the inspiration of an old post on the CF from Purplec4 showing a completely clogged evaporator, i decided it's worth a shot, since I just cant live without cold ac, and if I can't fix it, then I may just part with the car since most people say these ac's are marginal anyway. I know some of you who live in other states don't need ac at all, but here in sunny, humid sf..good ac is a must. But I still can't believe that Chevy would let a car leave the factory with an ac without enough force to blow out a match!

Purplec4's solution is to split the case leaving the inside case closest to the engine in place, and pull off the passenger side, then clean the coils with air, water, brake cleaner etc...Open to cleaning tips here..

So, I'm delving into it.

Took out antifreeze tank,blower motor, inner fender, side gill, windshield washer fluid bottle, square support arm that goes to the frame and I'm two small bolts away from pulling off the outside blower housing which i think I have to go down below the car to get to.

Even though I can see the outside of the evap fins without taking off the cover and it doesn't LOOK too bad, I'm inspired because it looks as though the inside of the fins may be clogged.

Wish me luck..i'm hoping for gale force ac when I'm done!

[GOLDCYLON]

Did you replace the AC/blower Controller rectifier? Its next to the blower on the top of the suitcase and you guessed it..... it controls the speed of the motor?

[Torchred96]

Well, no, I didnt test it, but I did measure the voltage at the plug and it was 13.9 and 14.1 depending on if the radiator fan was running....and the new fan was only marginally better, if at all.

[a1991zr1]

I HAVE THE SAME FRICKIN PROBLEM WITH MY 91 NO POWER TO FAN IT WILL INCREASE IN SPEED BUT THE VOLUME OF AIR MOVEMENT SUCKS

[Torchred96]

Okay, so I got it all disassembled and found it to be pretty dirty..

I cleaned it with water, carb cleaner, high pressure air compressor and even vacuum cleaner..

So, I decided to see if any air was actually getting through the fins...I put the vacuum cleaner on blow and put it up to the evaporator and ....hardly any air came through the other side....

I don't recommend this, but I did it..I pushed a wire tie through the fins through to the other side...Well, some of them went right through and others didnt go at all. I'm pretty sure the evaporator is still clogged but Its going back together as it is for now and hopefully its better than it was.

Any ideas would be appreciated.

Thanks

[Torchred96]

a1991z, I cant take it..The heat is horrible in south florida and it makes driving the z in the sun...NO FUN.

One thing I did do is took out the screens (plural) behind the evaporator on the engine side..

I'm sure someone will chime in and tell me why I shouldn't have, but to me, it's just another obstruction.

Okay, I did something else before I put it back together because I didnt think it was gonna be any better than before. .Since I tried to put tie wraps all the way through the evaporator (to clean out the obstructions) and some of them went through and others didn't, I assumed that it was because of dirt....so what I did was took a thin file and pushed it through the fins..Id say I did about 70% of them pushing all the way through..

After I was done, i put a light on the engine side of the evaporator and was able to see a lot of light through the evaporator.

I am really thinking that these evaporators are bad from the factory.

Anyway, I expect to see an improvement at least in air flow..

I know many of you won't like my solution, but if I get more volume of air to flow through, I get to keep the car...that's a win win situation for me.

thanks for reading.

[Torchred96]

I couldn't wait to try it..so I put the fan back in, hooked it up and...crap started blowing through the vents at me...That's a good thing!!..That the junk came out with enough force to actually hit me!!!!

I estimate about 50% more flow than before..I think I did okay..Tomorrow, I will put it all back together and take it for a test drive.

I've concluded that in my case, the fan was not the problem and that a clogged evaporator was. If you cant get flow through the evaporator, it aint gonna get through the vents.

[USAFPILOT]

why not just replace the evaporator?

[GOLDCYLON]

I couldn't wait to try it..so I put the fan back in, hooked it up and...crap started blowing through the vents at me...That's a good thing!!..That the junk came out with enough force to actually hit me!!!!

I estimate about 50% more flow than before..I think I did okay..Tomorrow, I will put it all back together and take it for a test drive.

I've concluded that in my case, the fan was not the problem and that a clogged evaporator was. If you cant get flow through the evaporator, it aint gonna get through the vents.


Actually I beleive it was a combination of these factors. Replacing at 20 year old fan motor and cleaning out your system did not hurt.

[Torchred96]

Dont forget 132k miles.

Usapilot: I didnt change the evaporator because:

1) I didn't know if that was going to solve the airflow problem.
2) I saw a thread in the cf that detailed cleaning it out.
3) It was already 7 at night before I started the project and no parts stores were open by the time I got to it.
4) I'd have to break the system open, , buy a $200 evaporator and then pay someone another however much to replace my accumulator, evacuate it , and recharge the system. So, that's probababy about $400 worth of reasons that I did for free.

Also, everyone says that these systems are bad right from the factory, Well, I'm pretty sure I found a way around that.... The answer for me, at least was to sacrifice slightly less cool air for volume. I don't know if a new evap would have gotten the volume I havde now, I've never seen a new zr1 or one with low miles on it for that matter. You have to decide if it is worth it to you. Plus, I didn't want to experiment with a brand new evaporator. I can always put a new one in...I bet I can do it in half the time ..but fixed costs are fixed costs. This one was free.

Those $500 dollar bills start to add up quickly to the point where it'd be better buying a low mile car if you don't do things yourself.

So far, since owning the car, I've bought injectors, a MH chip and gaskets for the job, and a blower motor.

The idea here is to not blow a fortune on a car I spent $8900 for.
Hey, at least, I'm not parting it out.

[sammy]

you might consider getting one of the vent covers that would stop alot of the junk getting into your system .

[a1991zr1]

i will tear mine done tonight sounds like a shitty but inexpensive fun project lol i will let ya all know

[Torchred96]

You won't be sorry. I'll tell ya right now, just cleaning it with a vacuum, air compressor, sprays etc won't do it.. In fact, when you get it apart, try to blow air through it after you clean it. I couldn't feel a difference with the before and after until I punched through the fins with a small, flat file about .030" thick. I put the file in a pair of vice grips for better punching power..you shouldnt distort the fins much at all, but you will be surprised how many are just clogged, even after cleaning.

If you do use the file idea, I assume you know you have to go between the vertical tubes or you will spring a quick leak. I had a bunch of metal filing that I had to wash out after the procedure.

Put a light behind the evaporator..if you cant see light through it, you won't get much air either .

There are two screws on the evaporator box that have to be gotten from the bottom..they are the only two. I had to take off the metal cover that covers the fuel filter and use a small wrench to reach up and get it with my left hand while lying on my back..It's slow, the the threads are coarse so it comes out fast. The 1" or so square cross memeber has to be unbolted.. It's 5 bolts, but all are easy to access (there's three under the right side hood latch..I didnt see that one. Take out the washer bottle and unplug it. Once you get all the nuts and bolts off the right half, the cover will come off, but it needs a little persuasion to get over the frame rail and the heater tubes..Just be careful not to break anything and only bend as you need to..take your time.
The heater hoses have to come off..sprayed with wd40 to help. I left one hose on the radiator tank

I know this sounds like a redneck cure..but it worked and worked very well.. Last night I said I got about 50 percent more air...That was before driving it and getting the extra air and RPMs. The improvement is far better than you will imagine. !!

[-=Jeff=-]

Evaporator info:

a Doc and a PDF from PurpleC4

http://vettextc.net/jeff/Evaporator/

[Torchred96]

Jeff..are you Purplec4? If so, thank you so much for the inspiration to tackle this job. It was really a piece of cake with your pics and instructions.

Like I said in a previous post...my evap was so clogged I opted to punch through about 70% of the fins with a thin flat file and took out the screens on the opposite side. The result is a flow of air that is even better than my 96's was. I hope that other people who think their z's ac are just weak from the factory try this simple cure.

Thanks again for the post!!

[-=Jeff=-]

No I am not, I know he sold his C4 and moved to a C5, but not sure after that. I was around the forums on Cf back then when he posted it

I am -=Jeff=- on most boards

[a1991zr1]

got mine tore down and was shocked at who crapp filled this was and was almost like tar. Used 6 cans of break lean and my air compressor and finally got air to blow through it. will post pics later camera battery has died and has to charge to recov:proud:er pics

[mgbrv8]

I have always wondered if anyone has put a pusher fan in front of the condenser to help the efficiency?

Dave

[a1991zr1]

I have always wondered if anyone has put a pusher fan in front of the condenser to help the efficiency?

Dave

great idea I wonder if that would help. or if they make a high flow condensor

[Torchred96]

Before I did mine I was thinking the same thing, wondering if someone made a higher performance fan. I wonder why no one has done this yet.

a1991, did you you keep the screens that were in back of the evaporator? I took a pair of channel locks and pulled it out..it's glued to the back of the evaporator. In my car I believe there are 3 or 4 screens, one on top of the other...though they weren't clogged, I can't see how that in itself isnt a big hindrance to airflow.

When I changed my fan motor earlier in the day, I looked inside the evap housing with a light and mirror and it didn't look bad at all...in fact nothing like Purplec4's. But when I got it apart, I noticed even after cleaning it out, it didnt flow any air with my 5hp shop vac trying to push through it...so I knew I wasn't gonna be happy until i figured out how to get more air flow.

I'm glad you tore it down...Wasn't nearly as hard as I thought it was going to be.. I think I was more intimidated by that housing than the plenum pull.