Ac Problems

[~ E30 ~ Pimp ~]

hi guys, just wondering why my air only gets reall cold when im on the high way or going past 40mph. In stop and go traffic, or just sitting at a stop light, the air doesnt come out that cold, like 78degree air coming out. when im past 40 it comes out freezing. I already replaced the r-12 with r134a also, can't seem to understand the problem ghead . Any help would be great, thanks!

[PBEM]

Originally posted by ~ E30 ~ Pimp ~@Aug 25 2005, 09:42 PM
hi guys, just wondering why my air only gets reall cold when im on the high way or going past 40mph. In stop and go traffic, or just sitting at a stop light, the air doesnt come out that cold, like 78degree air coming out. when im past 40 it comes out freezing. I already replaced the r-12 with r134a also, can't seem to understand the problem ghead . Any help would be great, thanks!

[snapback]372510[/snapback]

Tell us some more about the history of your ac trouble. Who told you to take out the R12 ? The symptom you describe could be a number of different things. are your fans working ?

[yammahamma]

I'm having this same problem....and I don't have a solution.

Mine is still the original AC unit that she's had since birth and it's only cold on the highway.....

I would love a solution to this as well....does it just need more freon?

[~ E30 ~ Pimp ~]

well when i got the car, the ac did not work at all. So i replaced the r-12 with a 134a kit i got at autozone,, and it worked fine. Then i noticed that while i was at a stand still it wasnt as near as cold as when she is moving down the road. The fans are working great, blow air out real good. Most of my time is on the high way anyways but i would like to find what the problem is so it is at its best on the street as well. thanks for any info.

[325eXTATIC]

Originally posted by ~ E30 ~ Pimp ~@Aug 26 2005, 12:37 AM
well when i got the car, the ac did not work at all. So i replaced the r-12 with a 134a kit i got at autozone,, and it worked fine. Then i noticed that while i was at a stand still it wasnt as near as cold as when she is moving down the road. The fans are working great, blow air out real good. Most of my time is on the high way anyways but i would like to find what the problem is so it is at its best on the street as well. thanks for any info.

[snapback]372542[/snapback]

Generally speaking, the reason that your AC doesn't pump well when the egnine is at idle is because the compressor is driven by engine speed, and if the engine is at or near idle, it isn't being spun in it's efficiency range. If you ask most anyone here in Georgia, where the heat is INSANE, when their NEW car is stopped at a light, they will get warmer because the compressor isn't pumping fully. My girlfriends new Trailblazer (not a great vehicle I admit!) doesn't keep the car cool for SCHNIT when we stop at a light, but at freeway speed, it can cause ice on the bottom of the windshield.

Bottom Line... It sucks, but there isn't much you can do about it, unless you are as inventive as these kids (http://www.sltrib.com/utah/ci_2841984) and can adapt a peltier cooling system to your car, there isn't much that will change.

Just my observations since I live Atlanta, also known as Satan's ASSHOLE!

Josh W.

[ldsbeaker]

At lease your AC works. I still have to fix mine...

[325eXTATIC]

Originally posted by ldsbeaker@Aug 26 2005, 09:21 AM
At lease your AC works. I still have to fix mine...

[snapback]372609[/snapback]

I should have mentioned that part... I have to rebuild my system as well! I have fans, but that doesn't help when the mercury hits 100 Degrees, and 85+% humidity! YeeEESH!!!

Josh W.

[Bear]

Hmmm, I had a 1988 750 until this past May and I converted her to 134a about four years ago (I did vacumn her down and replace the reciever /dryer) and in heat indices of +105 to +110 even at idle I could pull +45 degree air at center vent (original compressor). I would first put some dye in the system to see if you have any leaks an after that vacumn here down and refill. Quite often the receiver/dryer dessicant disintergrates and this tends to degrade the system. I live in SE Virigina and it gets hot and humid, do not know about Hot Lanta, but do know about Stockbridge and Henry county and I have survived there in the summer with the 750.

[325eXTATIC]

Originally posted by Bear@Aug 26 2005, 09:54 AM
Hmmm, I had a 1988 750 until this past May and I converted her to 134a about four years ago (I did vacumn her down and replace the reciever /dryer) and in heat indices of +105 to +110 even at idle I could pull +45 degree air at center vent (original compressor). I would first put some dye in the system to see if you have any leaks an after that vacumn here down and refill. Quite often the receiver/dryer dessicant disintergrates and this tends to degrade the system. I live in SE Virigina and it gets hot and humid, do not know about Hot Lanta, but do know about Stockbridge and Henry county and I have survived there in the summer with the 750.

[snapback]372621[/snapback]

Wow, Stankbridge! That is actually exactly where I live! LOL! And before that I lived in McDonough (heart of Henry County) but I work in North Atlanta.
It is my experience that bigger cars have more efficient compressors at lower speeds, because generally speaking, larger cars have larger, lower revving engines, but you are right, that is an EXCELLENT idea. Get an AC leak kit (usually a dye and glasses to see the dye with) and check your entire system. And if no leaks are found, I say replace the receiver/dryer with an R-12 version, since everyone that has put that combo together says that with the R-12 receiver/dryer, their at vent temps were 5-10 degrees cooler than with the R-134 version. That could help with the lower low speed high vent temp issue a bit.

All I can say is AT LEAST YOU HAVE A/C!!! LOL

[nukeduster]

switching to 134 will produce worse results, not better

r12 has much better cooling capacity then r134a could ever hope for



also if you didnt do a complete vaccuum ont he system before you did it its going to be contaminated and wont work well and will quickly kill itself(compressor)


check to make sure your a/c fan works properly (the outside fan infront of the condensor, not the interior cabin fan)


if it doesnt blow at a VERY high speed when the a/c is on and its very hot outside @ idle then the fan isnt kicking into its highest setting and the resistor is probably bad on the fan.

check that the fan evne works first and foremost.

check to see if you have the correct ammount of cooling charge in the system by revving the engine to 2k rpms and check the peep glass for streeks or bubbles.. if you see streeks youre good, if you see bubbles you need more.

when you refilled the system(assuming you vaccuumed it), what kind of oil did you use?

a/c is fun to work on if you cant already tell...

[~ E30 ~ Pimp ~]

awsome reply's, thanks guys, looks like i have work to do this weekend... if it doesn't get that hot . Thanks again.