How cold should the A/C be at idle? Feedback appreciated
 

I've had my 89 DX for about a year and a half now. The A/C always worked, but it sure didn't push much air out (fan speed 4 felt like 1), so it was pretty much useless.

After some inspection we noticed the evaporator was completely irreversibly coated in thick hard resin-like black crud (in addition to cat hair galore). Last week we replaced:

Evaporator
Expansion Valve
Drier
Condensor

Converted to r134a in the process and replaced all o-rings where applicable

4 oz of Pag oil, pulled on vacuum for half an hour, and put in 2 cans of r134a (about 24 oz.)

Charged per FSM procedures

Now, on the highway the a/c will blow just under 50 degrees (measured at the center vent) on a 95 degree day, which is plenty cool. The problem comes in stop and go traffic. Sitting for more than just a minute or two, the air temp. at the center vent gradually climbs up to about 80 degrees, which just isn't cutting it. A few hours of searching and it looks like the condensor fan and just plain not enough freon are the common culprits.

So -

1) How do I tell if I actually have enough r134a in the car? There realistically is probably around 19-22 oz. in the system, but I'm not sure how to tell exactly. I had trouble getting the 2nd can to empty, and had a small bit hiss out when removing the manifold lines. However, the sight glass showed no bubbles (which, according to the FSM indicates a full charge).

2) What is the exact amount of pressure that should be in the system? I can't seem to find this anywhere. I came across one thread that indicated 42 psi was the max, but can't seem to find anything confirming it.

BTW, how is it possible to tell exactly how much r134a (in ounces) is going into the system (I know two 12 oz. cans makes 24 oz. but what if you needed, say, 18 oz.)? This was my first time doing A/C work, and I dug around high and low for information and the proper tools to do it, but I can't for the life of me determine how to gauge this.

Anyways, would appreciate any feedback.

Re: How cold should the A/C be at idle? Feedback appreciated (James89DX)
 

if you are getting 50 degrees out of the vents, that's awesome. usually it will be 55 degrees, give or take. i would say the system is at full charge. at idle or in traffic, there is no way to keep it cold except for the fans. at 95 outside, that is a tall order. a better performing condenser fan or fans may be your only other option

Thanks for the reply. I know the condenser fan is working (I mean, I can see it blowing), but how well is anyone's guess. I would think it'd need to pull a pretty darn high volume of air through the radiator/condenser to mimic normal driving conditions.

I tested my mom's 2001 Elantra, and at idle it blows between 50-55 degrees, and under driving conditions gets down near 40 degrees.

I'd like to get mine to blow not much higher than low-60's in traffic (which I noticed the past couple of days is the threshold of your back sweating to your seat https://honda-tech.com/forums/images...s/emsmilep.gif).

Guess it wouldn't hurt to try a new condenser fan. Wonder if there's any higher power ones available.

Re: How cold should the A/C be at idle? Feedback appreciated (zrickety)
 

Well, there is a decal on our cars that saying that the A/C systems takes around 32 OZ of r12 so I guess that for r134A should be around 30 almost 3 cans, since 134a requires less.... Is the blower in good condition? For a recharge, the blower needs to be at maximum for the evaporator convert liquid cold freon to a cold gas... If you see water on top of your compressor, that means that the evaporator is not doing its job like its supposed to........ The expansion valve will expand depending on the evaporator temperature.

You might not see bubbles when you start the car in the morning but after you run the car, open the hood and inspect the receiver glass for bubbles... You might need to add freon... pressures should be around 45 on the low side and I think 200-220 on the high side...

another alternative, when you get home, let the car at iddle and throw some water to the condensor using a water hose.... If it gets cold then that also might be your problem..... Do you have 2 fans??? pulling air from OUTSIDE the car towards the engine bay (otherwise, the air will run first to the radiator, heating up the air and heating up the condensor). The condensor job is to convert the freon from a hot gas to a hot liquid. If you dont see any bubbles in the glass that means that the condensor is doing a good job on converting the gas to liquid state.

Also, make sure that the fans are strong (dont stick your hand on it lol) and dont paint your condensor... You said that the condensor is new so I doubt that thats your problem...

I hope I helped
https://honda-tech.com/forums/images/smilies/emthup.gif


Modified by JUN. at 8:12 PM 6/30/2008

Re: How cold should the A/C be at idle? Feedback appreciated (JUN.)
 

You might also wanna consider some window tints since our cars are small and they heat up pretty quick.

Did you clean the heater core also ? I think that the blower throws air to the evaporator, then to the heater core.

Since you said that your evaporator was full of crap, then the heater core might be the same.

Hmm, my car was a pure piece of junk (understatement - I got ridiculed for buying it) when I got it, and when I had it painted a year ago I had a new hood put on and all those stock decals/stickers are gone https://honda-tech.com/forums/images/smilies/emsad.gif I guess if it's 32 oz of r12 then it'd be a bit over 27 oz of r134a - but does the 4 oz of pag oil need to be taken into account?

My new drier doesn't have a sight glass, I was referring to the sight glass on my A/C manifold gauge set in my first post.

I'm just sort of scared of overcharging it. My friend had a shop put on a new compressor and charge his 90 Si hatch, and they put in 8 oz of pag oil, 3 cans of r134a, and it blew the compressor after not even a week https://honda-tech.com/forums/images...s/emsmileo.gif

I hadn't thought of two fans. I wonder if a couple of small-ish aftermarket fans could be fit in between the condenser and the front bumper?

*edit* No I didn't check into the heater core. The backside of the evaporator was completely clean and sparkling silver so I didn't guess anything really got through

Re: (James89DX)
 

so you dont have 2 fans?

Well, yes I have the two stock fans behind the radiator. I believe the condenser fan is on the left, radiator fan on the right.

Re: (James89DX)
 

are they pulling air form outside towards the engine bay?

check your highside and lowside pressures

Re: (James89DX)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by James89DX &raquo;</TD></TR><TR><TD CLASS="quote">
I'm just sort of scared of overcharging it. My friend had a shop put on a new compressor and charge his 90 Si hatch, and they put in 8 oz of pag oil, 3 cans of r134a, and it blew the compressor after not even a week https://honda-tech.com/forums/images...s/emsmileo.gif </TD></TR></TABLE>

I should have just done it myself in the first place, now the next two days will be spent doing it all myself.

The service manual says to wrap the expansion valve in tape. The old expansion valve had some half rotten mess that one could not guess what it was. Do any of you guys know what type of tape to wrap it in?

Also does anyone know the exact amount of R134a to use? I believe when doing the conversion it is 24.8 oz of r134a and 4 oz of pag oil. The idiots who did mine used 8oz of pag oil. The compressor blew r134 and oil all over my engine bay.


Modified by 90_Si at 3:08 AM 7/1/2008

Re: (90_Si)
 

its called a/c tape. Get it at any ac shop

Re: (JUN.)
 

Yeah they're both working, but upon closer inspection I noticed that my radiator is caved in right into the condenser fan, and the fan blades hit the radiator intermittently. I moved the fan out a so it didn't scrape but I may just swap in a non-bent radiator so I can have the fan smack against the radiator like it should be.

The quantities are different for the different a/c systems. The Matsushita cars required ~5 ounces of oil, whereas the Sanden cars required ~6 ounces of oil for 1988. For 89-91 oil level was anywhere from 4 - 6 depending on compressor and refrigerant was listed as 1.88-2.10 lbs. Likewise, R12 pressure readings should be 36 low side and 320 high side on an 80 degree day. How these figures transfer to an R134 swap, I'm not too sure of.

So for most of these cars, R134 should be anywhere from 25.5 ounces to 28.5 ounces because original R12 was rated at 1.88 -2.1 lbs and the R134 conversion should be 85% of the R12 rating.

Tinkered around on it today and noticed that the radiator was caved in on the condenser fan. I also confirmed that the condenser fan worked, but sure didn't move much air around.

I went to the junkyard and scored a new radiator (literally new!) and then installed a couple of 12" high-performance Hayden slim fans. One on the outside of the condenser pushing air and one behind the radiator pulling air.

I drove it around a bit to test it. Granted, it was 'only' 86 degrees outside, but driving it around in city stop and go traffic it never got much higher than 60 degrees at the center vent. I got stuck at a train stop at one point, and sitting there for 10 minutes idling it never got above 67 degrees at the center vent (before it was normally 75-80).

Pretty impressed with the fans. Hopefully it'll be HOT tomorrow so I can really put it through it's paces. Here's a few pics. I think you can click on the pics for larger sizes.

http://img4.pictiger.com/469/15862965_th.jpg

http://img4.pictiger.com/930/15862948_th.jpg

http://img4.pictiger.com/29c/15862937_th.jpg

http://img4.pictiger.com/ace/15862919_th.jpg

I'm actually thinking of putting a 6" pusher fan on the right side of the condenser, but need to do some research to see if the pusher fan with a puller fan just a few inches behind it will be overkill. Tempted to try it anyway https://honda-tech.com/forums/images...s/emsmilep.gif

Re: How cold should the A/C be at idle? Feedback appreciated
 

I was wondering, if you're still around on this site, if this solution worked out for you? This thread is the closest I have found in the H-T archives to my problem. Let us know how the new fans held up in the high heat!

Re: How cold should the A/C be at idle? Feedback appreciated
 

bump...update us james

Re: How cold should the A/C be at idle? Feedback appreciated
 

I'm still around here

To be honest, the electric fan didn't really help much, plus it's REALLY loud. It helped a LITTLE bit but but in city driving during Texas 90-100 degree heat it would still blow 80 degrees at the center vent. R134a is just pure and simple absolutely crap-tastic in EF's. To make it even remotely adequate, you would need an r134a-type condenser (among other things), and as far as I know there aren't any available for the EF unless you have one custom made.

Of course, you'll have people on here claiming their r134a conversions work great, but I would say they're either exaggerating out of slight denial or delusion or they don't live in truly hot/humid climates (keep in mind here that Honda Tech is also full of people who claim a/c is unnecessary, so if this is the general mindset of the community then of course completely lackluster a/c performance would be acceptable to them). Otherwise, we must have completely different ideas of "comfort".

I actually got so fed up with it that I took the costly and time-consuming route and reverted back to r12 in late September or so of last year. By then, it wasn't so hot so I couldn't truly "test" it, and then in October my engine developed a massive oil leak, so I put it up in the garage for the winter and completely rebuilt the car (engine, front end, new/rebuilt Si tranny, MPFI swap, etc.)

This spring, when I was done with all the work, I noticed the a/c system has absolutely no charge. It looks to me that the shop who charged the r12 for me put on a wrong cap on one of the Schrader valves and it all leaked out. I was so fed up with it at that point that I've basically parked it for the summer and have only driven it a few times since.

In the meantime, I've joined several a/c automotive forums and picked the brains of ACTUAL a/c experts and the general consensus is that 1) r134a conversions in EF Civics suck because the proper condenser isn't available for it and 2) the a/c system in EF Civics is so rinky-dinky from the factory that even with r12 it was probably borderline adequate at best, and so of course half-assed r134a conversions suck

So, that's where it stands. As of right now, I'm sort of back at square one, although when I finally get back around to it, I will most certainly be staying r12

Re: How cold should the A/C be at idle? Feedback appreciated
 

if it doesnt blow hard on 4 then in probly the resister for the ac controls and did u replace ur orfice tube

Re: How cold should the A/C be at idle? Feedback appreciated
 

Depending on weather outside I get anywhere from 39 degrees to about 46-50 very hot cali days 100+. I just got my ac system serviced few years back and its been holding fine without any big leaks. I have a r12 system. I did some test on my moms corolla 99 r134a and my car. During same day temps on the r12 system were actually colder..

Re: How cold should the A/C be at idle? Feedback appreciated
 

Bingo, that's what I hope to achieve if I can ever get around to getting the thing functioning properly.

I have two '92 Maxima factory r12 cars that'll both get down instantly to about 45 degrees at the center vent. I also have a '93 Maxima project car that's factory r134a, and the condenser and evaporator are different, and every line and component all have big stickers on them saying they're r134a specific.

Now, keep in mind the '92 and the '93 Maxima are the exact same car, so if "converting" to r134a were as simple as running some Pag oil and charging it with r134a, you think Nissan would go through the trouble/cost of manufacturing r134a specific lines and components, etc.?

So, same with the EF. If we could get r134a type condensers and whatnot, then I'm sure the "conversion" would be adequate, but without all that stuff r134a in an EF just flat out sucks donkey balls.

Re: How cold should the A/C be at idle? Feedback appreciated
 

Huh, whoever said it didn't blow hard?

My system blows just as hard as factory, but, for the record, the EF sucks in that regard too. Setting 4 on an EF is like setting 2 on any other car.

So, if I ever get this thing going good, I'm actually going to retrofit in a blower motor from something else