Newbie question: Seats and A/C

I have a 3.2 in Houston. The A/C is marginal. I would go with the T if you don't like to sweat (also has power steering)

 

If the A/C is the deal breaker then I would go for another car

 

My 308 QV has A/C that actually works pretty well. The only time it really got hot was after a REALLY long drive (500 miles) which I think was just heat soak from the engine. For around town jaunts it works for me just fine. Maybe mine is the exception though??


PDG

 

My 1983 308 GTBi QV has immediate ice cold a/c (in near 100 degree weather) too. I don't need to "crank it up" and wait, either.

 

I would recommend 'not' converting away from the R-12. The newer systems that run R134 are sized for the reduced chilling capacity of the refrigerant. You can readily purchase R12 and the mineral oils from eBay, if you pass a simple online EPA exam. The vent temperatures on R12 systems are below 38 degrees, and it makes a difference in cooling

 

IMHO, what a 328 needs to provide good ac is too move more air through the system - a larger or more powerful blower. My 328 (w 134 conversion) cools very well BUT, the thermostat, even at the coldest setting, will cycle and shut off the compressor earlier than it should to really cool the cabin. THis is due to the fact that the temp sensor in the plenum gets too cold too quickly and thinks that that car cab is cool enough when it is not. If more air was running through the plenum, the air temp in the plenum wouldn't be a cold and the sensor wouldn't cycle the compressor off as often. Note - I realize that a system which is low/high on coolant can cycle on/off improperly due to high/low pressure. Coolant charge and system pressures are correct on my 328. I have often thought about just bypassing the temp control switch which would put the ac on MAX all the time and eliminate compressor cycling but I haven't bothered with it yet. Another thing that I believe would help would be to relocate the plenum sensor right at the outlet instead of well back in the plenum where the air is colder.

One "improvement", which was posted by someone here a while back, was to orient the dash airvents TOWARD the windshield so that the air leaves the vents and hits the windshield first, travels up the windshield and into the cabin. I was skeptical of this being useful but was surprised at the difference it made.

However, as has been noted, if AC is a critical issue, it might be best NOT to consider the 3x8, at least until you try several of them to see if they will work adequately in the TX heat.

I drove my 328 across country in Aug '08 and the AC was "fair" but no better than that. It was fine in the early part of the day or late afternoon but in the middle of the day, unless it was cloudy, it was better than opening the windows but certainly not "adequate." However, at that time I hadn't heard of rotating the vents to the windshield so it might have performed somewhat better had I done that.

Also note that some folks believe that a "better" compressor will help. This is not really true. The same York compressor that is in the 328 cooled Lincoln Continentals, Chrysler Imperials and Cadillacs at least from the '60s onward. The ac in those cars would run you out of them if set to max so the compressor, as far as capacity is concerned, is not an issue. Yes, newer units are smoother/quieter but replacing the York with one of them will not improve your air conditioning.

One more note - although R12 is a more efficient coolant than R134, the fact that the sensor shuts off the compressor because it thinks the cabin is cold enough, indicates that at least with the 328, R134 works fine. It's the sensor shutting off the compressor that keeps the cabin too warm. So in this case, the coolant is not the limiting factor since it would do exactly the same thing (shut off the compressor) with R12.

 

My 82 Mondial had a charged system, upgraded center vents that actually pointed up, and the A/C was STILL all but useless.

 

FWIW, bypassing the sensor/switch only ends up freezing the condensor. Mine's bypassed because someone cut(!) the tube thingy out of the way

 

I think it would be important to determine which sensor is shutting off the compressor if you havent already checked this out? Low pressure, condenser coil, evaporator coil, cabin temp sensor? Maybe Jump the compresor clutch to just test your theory. You may be on to something, or you may find the Evap coil is icing up due to poor air flow and choking it self out, or the Condensor coil is too hot..?

 

"I think it would be important to determine which sensor is shutting off the compressor if you havent already checked this out"

It appears to me to be the thermostat itself, not any other of the various sensors. So the thermostat sensor "thinks" the car is cool enough so it cycles the compressor off. I suppose the control itself could be faulty. But as you noted, I probably need to do more exhaustive testing to be sure that some other sensor isn't shutting of the compressor. But, as I said, the system was serviced and all pressures were correct so I tend to think it really is a tstat issue.

On similar old systems, the T-stat switch usually had a constant-on position at the full cold limit of the switch rotation. As noted by Tillman, sometimes that would cause the evaporator to ice up if left in that position for a long period but at least you had that option.

 

What you have said is EXACTLY what my A/C guy said. He suggested fitting a manual thermostat which could be adjusted via a screwdriver to the correct setting.

Dumb question but where is this thermostat located? Any pics? Thanks........

Bob.