AC problem, not cooling enough

[grave77]

I exchanged the cooling radiator and the valve 2 months ago, I also refilled the ref. Gas 134, AC is fine when the fan is slow, but when I need more cooling by increasing the fan .. it gets warmer, as if the AC is not so efficent at higher fan speeds. what is the problem here?

[winfred]

check that the electric fan is working, it's the same fan as a e34 and subject to the same failing resistor, usually when the resistor dies the fuse dies not long after from the fan trying to start up in high speed

[grave77]

well the fan is running fast already as the low spead is not working so I bypassed the low speed so the car wont heat up in the traffic.

[winfred]

forcing it to start in high may pop the fuse and leave you without a aux fan, the starting draw is pretty high on these motors but they get around it by it starting off in low and if needed switching up to high, your motor may be in above average condition the reason it hasn't popped the fuse, it's hard to measure but they seem to average around 50 amps for a half second, some getting into the 60s, you don't want to weaken the fuse to the point that it looses capacity and heats up cooking the fusebox, seen it happen

on to the ac, sure you got it full of r134 when you converted it, could just be low, when i really want to tweak a ac system i block the throttle to about 1500-1600 rpm with the ac on full, rec on, and when the fan clutch is locked and not cycling on and off, a digital thermometer makes this easier but you can use a analog (just harder to see the changes) when it's as cold as it will get trickle in a little freon and watch for the temp to drop, and when it get as low as it will go give it a little more, you know you are full when it comes up a couple degrees or the compressor starts cycling with the blower on full, the listed capacity it not a set in stone number doing it this way gets you about as close as it can get

[grave77]

I already bypassed the fuse with a wire, cuz it did blow even when it was in 2 speeds. but from the fan tone it seems to run fine now.

8 series lack front ventilation, it traps the hot air in the front engine compartment until the car starts moving again. also on traffic lights it starts to heat up unless I rev the engine a little to 1000RPM.

so I was thinking of a small modification, that I increase the crank pulley to make all the other driven equipments go 5 - 8% faster

it will solve many issues, fan speed, AC, and force the hot air out of the engine compartment.

can you advice me with a cheap digital thermometer?

usually I ask them to fill the freon to the max but they always say its no good for the compressor, and they just cool the condenser with water with a little throttle up.

I would ask them to fill it with the blower on the max this time. might be better.

[632 Regal]

charge the damn AC yourself, it is not rocket science, for what you pay you can get the gages to fill it properly. Win is right on the accesory fan might not be running but you say it does... the only thing left in the equasion is your clutch fan may be weak and not doing its job. These cars run fine in southern USA which is hot there too and dont have problems. not the same indeed but if everything is working than no probs.

[grave77]

I will do that this Friday, just one last question, does the freon quality make a difference? we have 4 types here, China, India, Spain and English made freon types. each one has a different price, sure the Chinese is the cheapest.

as for the over heating issue, if I rev the engine to 800RPM it cools down again, or if I just open the hood it will not heat up too, otherwise if I left it idle it will start heating up after sometime, would this be a bad thermostat? or would it be rated around 90C degrees?

[shogun]

if I left it idle it will start heating up after sometime

Not a bad thermostat, but a bad visco clutch.

MWrench has made a nice write up to test it and he is an E31 expert
http://www.mwrench.com/Whitepapers/FanClutchtest.pdf

[grave77]

visco clutch is working fine, I need to rev the engine just few hundreds (800 RPM) and it will cool down or just to open the hood and leave the hot air go out at idle and it will cool down too. I guess the E32 has better front ventilation than the E31. this happens at 119F +/- 65% humidity

[grave77]

it turned out to be half the amount of Gas in the system, charged it and now its better. I hope it's not another leak !!