5 Liter Eater

If it's 95 out it should be 237# technically. That sounds a little high though. I would want to see you at least in the 200's though, with the engine @ ~1500. But it's blowing cool when it has enough airflow. What you described doesn't sound abnormal (vent temps warmer at idle) given the IC in front. But the fact that it wasn't doing that before is odd. I've always had the best luck vacuuming it and filling it to factory spec.

a/c man

AJ. tell me about the ABS mine is acting stupid now, where to get one rebuit and how much? thanks scotty

ajrothm

I was getting the 1216 code which indicates a bad relay in the ABS module. Mine would intermittenly work, most of the time I was getting the ABS/TC light on and nothing would work on the ABS/TC...

I sent it to ABS Fixer and he fixed it and had it back to me in like 3 days... Around $165 shipped... So far, so good...But I've only put a 30-40 miles on it so...We'll see how it does.


Thanks Bill,
Ill get the gauges on it this weekend and take better notes of the pressures vs vent temps.. I have a half can left I can throw in it.

In my first attempt to charge it, I got it very close to the factory spec of 1.75 lbs, which would be around 28 oz..... I put 25 oz in it and it wouldnt go below 70* vent temps, 25 psi low side/155 psi high side.... I added another half can or so and it got the pressures up and vent temps down but...It wasnt consistent...Nor did it hold there...Acting like it was undercharged...

a/c man

seems like mine took 3 cans,

BLOWNBLUEZ06

2 cans. That's it. You'll be a couple OZ short, but it cools great.

Great work AJ!
Speaking with a AC tech I respect years ago, I was advised to not add oil unless either it's a brand new system or you saw it all come out. When the refrigerant leaks out, most of the time that's all that comes out. Maybe a little oil, but not enough to justify adding much, if any at all. Adding too much oil can cause problems with heat exchange.
HTH.

neutron82

http://forums.corvetteforum.com/c5-t...r-fleabay.html ... pretty easy fix if you're getting a 1214 code... mine came on one day while driving and I found that thread and took my ebcm out and resoldered the relay and everything works perfect

5 Liter Eater

Yea I didn't mention it but I don't like that you added oil either. It's possible that too much oil is creating not enough room for the refrigerant is keeping it from cooling right. But put some more in it first and see how it acts.

ajrothm

Yeah I only added a 3oz can which had 1oz oil, 1oz freon, 1oz Perfomance additive. I know it had to have leaked a bunch of oil because the lower half of the engine compartment was covered in the crap from when the compressor o rings were leaking. I had added 1 can of freon each month for 3 months in a row just to keep the AC going until I had time to fix it.. I had not added any oil back in the system at this point so I am sure I easily lost 1-2 oz over the 3 month usage with the leak...

But yes I agree, something isn't right. I'm gonna work on it Sunday and report back.

a/c man

If you were closer I would help you with the A/C I have a really good vacuum pump and new Orifices I'm sure with a good vac and 2 cans like Brett said you will be good

I think your oil is good

ajrothm

Ok, round 2 with the AC work. Drove it to work and back home today, the system was ran for about 45 mins at the time of this test..

*Ambient Temp was 95*
*Humidity was 67%
*Idling @ 900 rpm
*Coolant temp was 234* (hot as crap)

AC/blower settings:



Getting these temps


With these pressures:


Lower for some reason, maybe the system cycled off? Compressor stays engaged the whole time...(non cycling compressor)



Sweat on the suction line


Going down the road at 70 mph, coolant temps at 212*, I was getting 41-45* out of the center vents, but as soon as I start idling, the vent temps start jumping into the 50s.... It never used to do this before. It sure acts like its low on Freon... Probably has atleast 2.5 cans in it at this point.

FYI... Cruising at 2000 rpms at 65 mph, blower speed on MAX, I was seeing 58* vent temps, which is about what the GM chart calls for at 97* and 67% humidity.. However this system used to stay at 40-42* so I KNOW its capable of better temps and more consistent.

So whats next? Too much Freon? Not enough?

Evacuate it and start over?

BLOWNBLUEZ06

What has always worked really well for me is to stop the engine and look at the temperature on the R134a scale and make it match the ambient temperature outside. If it's 100 degrees outside, I make sure the pressure reads 100 degrees on the R134 scale on both gauges. 100 degrees ambient is about 125psi on the gauge. Then Start the engine and at 100 degrees outside, I expect the pressure to be around 45-55 on the low side and at least 250 on the high side. If those pressures don't have a big spread, you could have something wrong, such as a dirty orifice tube.

Here's a little troubleshooting guide that may help. They don't mention too much oil in the system as a possible cause, but I've experienced that situation personally. Also, some refrigerant cans include oil, making the problem even worse. If it's got too much oil in it, you'll have to evacuate it, flush everything out, I would replace the dryer and orifice tube while in there, remove compressor and drain it and then add the proper amount of PAG oil to the system.

a/c man

I agree with Brett. Good info. At this point I would start over new orifice or clean it, Pull a really good vac. with a good pump, recharge with factory # of oz. make sure you purge you hose before charging making sure you don't get any air in the system.

5 Liter Eater

Those pressures seem too high. I know it was hot out today but it damn sure wasn't 106. So lets say 95. That would be 240, 250 max. Approaching 300 is overcharged. I'd let some out first, down to ~250, and try again. If it doesn't get better than open it up and check the orifice tube. If it's clogged you can just clean it out or replace it if you like.
Oil level is a tough thing to gauge. But typically the majority of it stays in the compressor, but yours was leaking down by the compressor so its possible it leaked some oil. I don't think that's the problem though.


But really it's not acting different than I would expect for a 1000 HP car. Mine behaves pretty much like yours does and I've never been able to get it any better. It's just that the condenser is not getting enough airflow at a stop, mostly because of the intercooler but it generates more heat than stock as well.

BLOWNBLUEZ06@RKT Performance

Temps coming off the hot pavement and these cars vacuuming air off of it, 106 doesn't surprise me.

ajrothm

Hmmm..

Looks like its pretty close to the GM specs:

A/C Performance Table Ambient Air Temperature
Relative Humidity
Service Port Pressure
Maximum Left Center Discharge Air Temperature

Low Side
High Side

13-18°C (55-65°F)---Ambient Temp
0-100%--- Humidity
211-241 kPa (31-35 psi)--Low Side
500-740 kPa (73-107 psi)---High Side
8°C (46°F)--- Maxium Center vent temp


36-40°C (96-105°F)
Below 20%
226-256 kPa (33-37 psi)
1280-1650 kPa (186-240 psi)
12°C (54°F)
20-40%
218-248 kPa (32-36 psi)
1360-1870 kPa (197-271 psi)
12°C (54°F)
Above 40%
211-241 kPa (31-35 psi)
1520-2100 kPa (221-305 psi)
12°C (54°F)

41-46°C (106-115°F)
Below 20%
238-268 kPa (35-39 psi)
1460-1830 kPa (212-267 psi)
13°C (55°F)
Above 20%
226-256 kPa (33-37 psi)
1570-2100 kPa (228-306 psi)
13°C (55°F)
47-49°C (116-120°F)
Below 30%
238-268 kPa (35-39 psi)
1750-2090 kPa (254-303 psi)
14°C (57°F)



I'm gonna go out and take some static readings with it not running. I can't see the orifice being plugged up, the system was working great before I took it apart to change o rings....It just leaked a can of Freon out every 2-3 weeks.. I did have a pic on my phone from when I was adding Freon back before summer and the gauges showed 20 psi on the low side, 155 psi on the high side, that yielded 40* temps, but it was not nearly as hot outside and the car/system was not heat soaked.

Thanks for the tips guys, I'll report back soon. I may try letting a bit of Freon out of the system and see if it helps but....I honestly think its going to get worse with less Freon.

ajrothm

Todays tests...

Static test cold, engine off.. ambient temps on thermometers.


Cold start, AC on Max/Blower on MAX, running for 5 mins:



At 2000 rpms





10 mins of run time.... System seems to have cycled off..




Out on the highway


Out of curiousity, I stuck the thermometers in the right side vent... WAY colder...Im sure the right side should be colder due to evap location but damn....That's a bunch..





Shut off for a quick gas stop, restarted and a short drive home(5 mins) and I couldn't get temps below this...


So I'm at a loss now... It almost seems like the system is charged correctly... Maybe a blend door issue? No codes or anything... I recently flashed a tune to the ecu and the blend doors cycled/reset so... Should be good.... Now I know why my wife freezes on the pass side while I'm burning up.. Too bad the left side is not the cold side..

5 Liter Eater

Could be that the recirculation motor needs to be re-indexed. Pretty common on the C5's. That would definitely explain the behavior.

5 Liter Eater

Super old and long thread on HVAC actuator reindexing:

http://forums.corvetteforum.com/c5-t...actuators.html

ajrothm

Thanks Bill! I'll check it out now.

danieloneil01

Headers look sweet in the bay.