Right new forum so lets give this a try ! Car : E39 523i auto built June '98 (note pre 09/98 DD42) Recently had the a/c re-gassed on my 523i & all was going well with nice cold air, until a couple of days ago when the air output turned to warm. My local garage (who did the RG) has checked the pressure, that the compressor is engaging/disengaging & all the air outlets buttons are functioning correctly. Employing the recirculate facility makes no difference to the output temp. One theory is that the aux. fan doesn't run (all fuses checked) when the a/c is on, but then it never has over the 7 years I've owned the car & the a/c has always been efficient, though it needs a RG each summer (all 1250grams) My garage is very fair & won't keep blindly searching for a fault & running up an excessive labour bill as a result, hence my plea for any input that might throw up answers. Thanks for reading guys.
That smacks of one of two things - either the temp sensors in the HVAC panel which can get clogged up with dust and dirt, or the coolant system heater valves (left and right) under the bonnet. FWIW, because this BMWLand forum doesn’t have individual sub-forums for each series of 5 series it would be worth the formality of having the series (E12, E28 etc) as part of the title for every thread - perhaps even the start of each title so that readers can easily filter through to the cars they know about. Traditionally forums without sub-forums for each vehicle type get loads less traffic as people are reluctant/haven’t got the time to read each and every ‘5 Series’ thread to see if it’s to do with the cars they know about and can help with. Sorry if that sounds like a mini-rant, it isnt, it’s just an observation based on almost 30 years of reading, learning and trying to help on various car forums.
I appreciate your reply, I will vacuum the vent & pass your suggestion about the valves to the garage owner. You are quite right about prefixing tech. advice posts with the E code in the absence of a sub forum, I'll oblige in the future.
When you say they’ve checked the pressure, is that pressure at system off (maybe 5-6 bar) or also when the compressor is activated to then give the pressure difference (around 2 bar low side and 10 high) to see if the compressor is actually working? Also from those pressures they should be able to see if there’s a blockage etc.
Many thanks for your reply, the answer is I don't know but I will certainly pass on your comments to them when the car goes back in next week for further investigation.
They will need to weigh the gas to see if you lost any, hooking up a pressure gauge isn't a great deal of use unless it's totally empty, and you can find that out without a gauge. Assuming it is leaking, they should have put tracer dye in regardless, but a nitrogen sniff test is the better way of finding invisible leaks.
Thank you, I'm pretty sure they will have employed tracer dye but I will pass on your comments/advice.
First port of call would be a vacuum test there is a leak as u say it needs a regas each summer i would put ,money on it being the condenser though a small leak is very hard to show up but as the car is 28yrs old things do wear out also the seals may have become dry at the pipe joints if the system is empty and they can leak a very cheap repair
Appreciate your reply, I'm calling in to the garage tomorrow, so your comments/suggestions will be passed on. You're probably correct about the compressor, when the 'screen-wash pump was replaced recently they were pretty sure it was original .. so the compressor could well be the same vintage.
Not the compressor but the condenser its the radiator thats at the front of the car very common fail on many cars
'Ah yes sorry, now I've re-read your post & my comment about the compressor could well be the case with the condenser? Thanks again.
I disagree with the pressure not being any use based on my first post. If it’s lost enough gas to drastically affect operation, the running pressures should show it but will also give a good picture of other conditions if the gas level is good.
You can still get a decent pressure reading on gauges with 1/4 of the gas left, but the AC will be terrible
I've just had a thought (dangerous in my case) regarding something which may or may not be a clue to the issue, so please indulge me? It concerns the operation of the climate control. Start the car from cold, select the coldest setting & the auto button on the climate, the face vents to the 3 blue dots & I will get cool air to my face for the entire journey, regardless of the distance or time. Park the car & return to it after varying periods. Drive away & the vents (settings unchanged) will blow air that varies between warm & hot, dependent on the ambient temperature & even driving some miles with the fan at high speed will not cool it down unless the AC is used for a while, after which I can switch back to the fresh air/climate setting. nb. when selecting the mode buttons on the climate I can hear the motors operating & the air output direction changing. My garage guy is now on holiday until the 25th this month, so investigations are on hold until then, meantime I appreciate all your help guys.
If its being re gassed each year that does sound an issue - think i only gassed mine once in 10 years.
Same, it's designed to be left on. I had to have this chat with the old farts next door who are off to my AC guy tomorrow to see why it's empty
I do in fact regularly run the AC for periods outside of summer so I doubt lack of us is the cause of my issue, but thank you both for the advice. nb. you are communicating with an old fart, but no offence taken
I'm currently investigating the AC on my Alfa 33. Seems its a genuine Alfa install - i suspect dealer fit but I've found the factory install manual. Going to visit my AC guy and get his thoughts - everything accessible and seemingly available, would make the car even cooler that it is already (pun fully intended!)
