Air Conditioning

[M100 TWO]

MAC. fitted a new receiver/dryer for me the onley differance is the switch is in a different position size was the same see my earler post for tel and address

[LXADO63]

More progress has been made on my AC system. I replaced the receiver dryer and trinary switch, evacuated the system and had it recharged. However- the AC specialist would only add 1.5 lbs of refrigerant (they have no specifications for Lotus to refer to) whereas my local lotus dealer thought it should be closer to 2-2.25 lbs. The ac system is not cooling down the interior of the car very effectively and I suspect it is due to under-charging the system- can anyone verify what the correct amount of refrigerant should be for an elan se turbo?

[Doc Fizzix]

hey guys,<br><br>i need some help & advice on the a/c compressor. my compressor is producing a ringing sound like a pinking engine sound. i think it may just be the clutch tho cos it seems to be causing this noise whenever i rev it up a little. i can actually see something vibrating loose on the inside of the compressor pulley. would it come as a seperate replacable part or would i need to replace the entire a/c compressor (ouch!) ? the compressor seems to be cooling still but it keeps blowing the fuse. any part no and/or model of compressor would be useful.<br><br>thanks, in advance .... Rudz

For what it is worth, I had a ringing noise comming from my compressor about three months back. The bearing on the compressor was going out and I really did not feel like pulling the compressor off the car so I consulted with a local AC shop and together, we made a tool to pull the compressor pulley off the vehicle without removing the compressor and there for I would not loose my freon. Worked GREAT! Got the pulley off with the bearing and took the pulley back to the same AC shop, they pressed the old bearing out, put in a new one, I re-assembled the pulley and now it is as good as new.

I have some pics I was going to do a write-up, I will try to get to it soon so you can see the pulley puller I made.

[Ashaman]

Original R-12 spec is 26-30Oz. During conversion, you generally should charge 70-75% percent of the rated R-12 capacity...

Due to differences in systems, however, it is much better to charge by pressure rather than weight. What were the high & low side readings when he was finished? That is much more accurate indicator of a proper charge.

[rob]

As Asha said the refrigerant charge should be 28oz's. 1.5lbs is 24oz's (i think, to young to remember the imperial thing), so you really need another quarter of a lb adding to the system.

The 70-75% of capacity thing is already taken into acount with the 28oz's.

[LXADO63]

thank you for the information. If I recall correctly- I believe he told me that the pressure was between 35 on the low end and 150 on the high end. I will be charging the system to the original R12 spec as I was lucky enough to find a service shop that still had R12 available. I will take the elan back in tomorrow and have them add a little more refrigerant.

[Ashaman]

Heheh, yeah...that should be about correct; thanks Rob. The pressure looks a little low on the high side, but then it also depends on ambient.

You should not exceed 40 psi on the low side though, personally I think I would add a little more and closely monitor perfomance & pressure.

[rob]

as a quick rule of thumb, the liquid going into and out of the reciever should be luke warm to the touch, not hot (over charged) not cold (under charged (or very over charged)).

I would charge the system by doing this rarther than by weighing in the gas or looking at the pressures, but thats just me (old habits die hard).

[Doug]

and what is it you do for a living, Rob

[Sy V]

Well his profile says he's a dog's body but those of us that know him have been told he's an air conditioning and refrigeration engineer...of sorts!

[rob]

'of sorts' is about right.

My old tools are getting a bit rusty now

[nitroman]

I did 2 things today which greatly improved the performance of my A/C system. First I topped it up 3PSI to 35PSI, which is the maximum recommended for a GM system. The thing blows VERY noticeably colder now, like it was cooling a meat-locker. Good thing I'm made out of meat!

2nd I replaced the vacuum line to the vacuum-reservoir, which is located under the plastic fender-liner on the left-side of the car. It is the silicone silver line you see in both pictures. I would have replaced the other black vacuum line coming off the manifold right next to it but I've no idea where it goes; does anyone? In any case the car now blows through the dash vents far longer under heavy throttle before switching the output to the floor-vents now.

The other black line leaving the vacuum-reservoir goes through the firewall 2/3-way over to the right-side of the car, and as I had neither enough new vacuum-line left to do the job, and also with the right-side of the car just inches from the garage wall, that will be a project for another day. But it goes into the backside of the A/C selector switch on the dash fascia.

So there ya go. If anyone else has something to add please do.

Just read you other guy's posts. I used good old R-12 to charge mine and did it by pressure as I have for over 20 years now. Good thing I have several A/C hoses/gauges as the regular gauge I had always used for high-side readings had some rubber-deterioration & a slow leak. Just grabbed another one & used it instead. Have plenty of R-12 on hand to last several lifetimes; nearly 60-lbs of the stuff. Planning, it's all about planning really.

[nitroman]

manifold vacuum ports

[desmondsee]

been toying with the idea of custom fitting some late japanese ac system into the elan....eg toyotas, hondas, etc...they run really cold (almost freezing). but i am no engineer and know not what makes it possible or not...anyone done this? where i come from it's really hot.

i recently spend GBP300, didnt know what was changed nor seviced. it did blow slightly colder but after 2 weeks, dead.

if i did own an elise, the Thailand guys did make a custom a/c kit that is colder than the north pole. but as for elan, the demand isnt that great so its hard to locate any off-the shelf case......

glad to hear any thoughts...

[nitroman]

Desmond, the Elan's A/C system is more than up to the challenge of "freezing your ass off." This was ensured by GM's ownership during the car's development. This in no way is a 'dis' to the British. We all develop cars which operate well in the environment which we are in. GM tested the Elan in the Mojave Desert in the SW USA. The A/C system had to keep people cool in 110deg-Fahrenheit weather.

The problem with the Elan's A/C are the maddeningly complicated vacuum controls which will turn off or minimize the A/C system if it senses undue stress upon the engine (thermal loads or high accelerator settings). If there are any vacuum leaks at all it has the same effect of seeing dropping manifold pressure just as if you'd floored the accelerator. These lines are old and cracked from age & heat and need to be replaced, preferably with silicone instead of rubber which is a far more robust & long-lasting material.

Also, if you are in a high-temp environment do not switch to another coolant other than R-12 (aka Freon). Any other chemical is less effective at both absorbing and then releasing heat. It is a simple fact that R134a, which replaced R-12 in the USA, operates only 1/3 as efficiently in the time it takes to absorb & release heat quickly. These properties will be more noticeable when truly put to the test... which is why GM tested in Mojave, an extreme environment. Something which works fine in 90F temperature is woefully inadequate in 105F temperature & high humidity.

Again, replacing all the vacuum lines which can diminish the performance of the Elan's A/C system will allow it to perform to an adequate standard in sub-tropical South Florida, or any environment I know.

Doesn't replacing vacuum line seem cheaper and easier than starting from scratch; "throwing the baby out with the bath water?"

[donsladek]

2nd I replaced the vacuum line to the vacuum-reservoir, which is located under the plastic fender-liner on the left-side of the car. It is the silicone silver line you see in both pictures. I would have replaced the other black vacuum line coming off the manifold right next to it but I've no idea where it goes; does anyone? In any case the car now blows through the dash vents far longer under heavy throttle before switching the output to the floor-vents now.

The other black line leaving the vacuum-reservoir goes through the firewall 2/3-way over to the right-side of the car, and as I had neither enough new vacuum-line left to do the job, and also with the right-side of the car just inches from the garage wall, that will be a project for another day. But it goes into the backside of the A/C selector switch on the dash fascia.

I'm going to replace all the vacuum hoses. From the manual, it looks like there is a tee fitting in the vacuum line that comes from the vacuum reservoir - one leg goes to the microswitch, and the other goes to the A/C selector switch on the dash fascia. I'm wondering where the tee fitting is, and how to access it? Pull the fascia?

Thanks!