How is your hvac performing this summer?

[bazar01]

This is the first year I will drive the TI during the summer in SW GA after my daughter gave it back.
I did replace the ac compressor with a used one and the pressures look great at 35 psi suction and 220 psi discharge at 92F outside temp.
However, it feels like when the car is in stop and go traffic, the supply vent temp is not as cold as when the car is going above 55 mph. I will put a thermometer on the vent and post back the temp.

I think the condensing capacity is reduced while idling. It seems like the radiator fan is not enough to cool the condenser or could there be air bypassing the condenser? Do I need a condenser fan between the grill and the condenser coil?

What is your ac supply vent temp when it is above 90F outside?

[teetime4one]

Can't answer your questions...but, my AC is working great! I only use it on the HWY and turn it off upon exit. I noticed years ago that these cars don't have the power to run the AC in stop and go conditions. It's windows down at that time.

[bazar01]

Originally Posted by teetime4one

Can't answer your questions...but, my AC is working great! I only use it on the HWY and turn it off upon exit. I noticed years ago that these cars don't have the power to run the AC in stop and go conditions. It's windows down at that time.

I don't know why you would turn the ac off in stop and go traffic just when you need it the most so you can stay cool especially after eating out for lunch and heading back to the office.
SW FL must be in the mid 90s now and much hotter than SW GA.

It feels like the condenser is not able to run efficiently like it is not getting enough airflow across the condenser coil.
I will investigate the seal between the radiator and condenser coil and make sure air is not bypassing the condenser when the radiator fan is running.
If I see some gaps between the condenser and the radiator I will try to fill it up with foam insulation to make sure the air being pulled by the fan runs across the condenser coil.

I do not have any problem when the car is moving over 55 mph which means that the condenser is getting enough airflow across the coil when moving fast. While idling, no airflow, no liquid Freon, no cooling across the evaporator coil.

If sealing up the space between the rad and condenser does not help, I will install a pusher fan in front of the condenser coil to help the radiator fan.

I will keep you posted.

[ricky.91]

hi there, this my first post, i think you might want to check if your electric fan is running. not cooling in stop and go traffic but cools at high speed sounds as if the fan is not working.

[bazar01]

Originally Posted by ricky.91

hi there, this my first post, i think you might want to check if your electric fan is running. not cooling in stop and go traffic but cools at high speed sounds as if the fan is not working.

Thank you Ricky91.
My radiator fan is new and it is running.

I checked the gap between the radiator and the condenser. There is so much gap on the sides and bottom where airflow can bypass the condenser while engine is idling. At high speed, there is no problem with airflow.
So basically, while idling, the radiator fan is pulling air from the space in between the radiator and condenser and bypassing the condenser. So there is minimal air flow thru the condenser.
I went to home depot and got some foam insulation and stuffed them on the edges in between the radiator and condenser coils.
I will test it tomorrow at 2PM when it is the hottest time of the day.

If airflow across the condenser is not enough, I will put an extra pusher fan in front to help the condenser liquefy the Freon.

[jca]

I know that the electric fan is supposed to come on when the A/C is activated regardless of the coolant temp. Your idea for a pusher fan is very interesting...keep us posted. John

[BlackBMWs]

Just a note, when it reaches 105+ here in Sacramento, I usually place the recirculate button on so the A/C is cooling the previous cooled cabin air. In doing so, it will move from kinda cool to nice and cold. All three Ti's operate similarly.

One thing to check is to ensure the plastic air channeling components up front are intact so the airflow is directed efficiently through the condenser and radiator. My 95 active had been in a front end collision at some point and much of that plastic was damaged and never replaced. $8 at the yards for the correct panels off of just about any E36 sedan or coupe (or Compact).

[bazar01]

Originally Posted by BlackBMWs

Just a note, when it reaches 105+ here in Sacramento, I usually place the recirculate button on so the A/C is cooling the previous cooled cabin air. In doing so, it will move from kinda cool to nice and cold. All three Ti's operate similarly.

One thing to check is to ensure the plastic air channeling components up front are intact to the airflow is directed efficiently through the condenser and radiator. My 95 active had been in a front end collision at some point and much of that plastic was damaged and never replaced. $8 at the yards for the correct panels off of just about any E36 sedan or coupe (or Compact).

Good points on the plastic air channeling parts between the radiator and condenser.
I found out I have a lot of gap between the radiator and condenser so I put some foam insulation pieces in between so the radiator fan pulls air across the condenser and not from the gaps in between. It made a big difference. The vent temps are a lot cooler especially in traffic at noon.
I always run in recirculation mode.
I am good now as far as the ac is concerned.

[pdxmotorhead]

I cant find my cheatsheat but when i charged my AC the BMW uses a off pressure reading, and the system doesn't work well with it even a couple lbs off..

[Strawman]

Originally Posted by pdxmotorhead

I cant find my cheatsheat but when i charged my AC the BMW uses a off pressure reading, and the system doesn't work well with it even a couple lbs off..

Can you elaborate on "off pressure reading"? Also, what RPM should the engine be running when taking high-low A/C pressure readings? Thanks!

[bazar01]

these are the pressure readings on mine.

Engine rpm at least 2k rpm.
90F outside temp
High side: 210 psi
Low side: 30-35 psi

[xxxJohnBoyxxx]

You need to do a touch feel test, what I call the test anyways.

Start car drive 2-3 mile with A/C system running fan on high do not recirculate cabin air you want fresh outside air. After the warm up drive, idle for one minute. After the idle open the hood and ensure all fans are working. touch feel the cold side condenser line or return line right on the condenser, it should be warm to very warm. You should be able to hold your finger on it without removing it due to heat. If that is ok or not too hot then look at the dryer for a nice sweat at the line going back to the compressor. Make sure you touch the cold line or suction line right at the compressor and ensure it is cold. This needs to be cold since that cools the compressor and will extend it's life.



Condenser too hot and all fans working it might need a clean with acid. Condenser good but no sweat lines on suction return is low 134a or clogged screen before evaporator. I have included a link to charge psi for 134a gas. On the chart check all your temp and use the numbers it tells you to charge the unit. Also if the car had no gas at anytime or the system was open to atmosphere you need to pull a 30hg vacuum for 30 minutes before charging the system. Air or water vapor will cause all kinds of cooling issues..

Pressure chart: http://www.pacificseabreeze.com/tech...a-PT-Chart.htm

Bottom line is I think you have a charge issue, too much in the system

Best of luck, John S

[bazar01]

My AC is fine now. I don't think I have to add a pusher fan in front of the condenser.
I can idle in traffic and still get cold air at the supply vents just by blocking the space between the condenser and the radiator to prevent airflow from bypassing the condenser.

[bazar01]

We are in the mid 90F over here and my ac has been cooling really well even when idling.
All it needed was airflow thru the front condenser from the radiator cooling fan and sealing up the spaces between the radiator and condenser.

[andbham]

I am in Birmingham, AL which should be very similar in climate. I have found that my a/c starts running warm at times. If I turn it off for a minute or so and then turn it back on, I get cold air. I am guessing that due to the almost ever-present high humidity, the coil is freezing up and needs a minute to thaw out.
Just a thought.

Do any of the 318ti family come with an auxiliary fan in front of the a/c coil? My repair manual says all models of the 318/320 have one, but my ti is often different from what is described.