The Lotus Cars Community banner

1 - 20 of 31 Posts

·
Registered
Joined
·
256 Posts
Discussion Starter #1
So this weekend I take the Lotus to Sector 111s open house. It was kinda hot on the way home so I turn on the ac.. I knew it was weak but man, we were sweating and it seemed like it was barely working.

I looked at Sir Lotus's thread and thought, there is no way this will fix my ac.. sure enough I grab my thermometer and the AC is barely dropping a few degs. So I bet I'm low on R134a. I see these commercials for AC pro, do it yourself and read the reviews.. super easy. But I thought you need two gauges, one for low and one for high.. and maybe a scale to see how much R134a you're pumping in.. what ever, I'll bite.

I buy it, read the directions and watch the video.. Set the dial to ambient temp, plug it to the low side.. start car, full AC and get squeeze the trigger in 15 secs blast till it goes into the pressure range shown on the gauge.

I was low.. super low. I squeeze about half the can in and the gauge goes to the middle. But according to the dial, I need more cause its hot. AC is working good.. getting like 30 degs cooler air at idle. (~55-60 deg f). So I shoot more in. Gauge isn't moving. So I do more.

20 oz can is empty. Label says it has 17oz of R134a and 3oz of what ever. Lotus manual says I need .55Kg of R135a, which is around 19oz.. Hmmm, that's weird. So I go and buy another can, which is only 12oz.

So I start squeezing in more. Then my check engine light comes on and my AC clutch starts going in and out. Whoa... That's not good.. Gauge still says I'm low but now I've squeezed in over 20oz of r134a.

I start leaking out some of the R134a and the compressor stopped cycling (it would cycle like every 5 seconds or so). AC is blowing cold, so I take it for a drive. Then I hear this surging or dragging noise coming from the passenger side rail. It doesn't do it at idle or with revs but right off idle. Sounded like a tire rubbing a fender liner. It goes away when I turn off the AC.

I drive back and leak out more r134a, a lot more. The weird noise stops and the AC is blowing cold. Check engine light is still on (may need time to clear, but I'll check it this weekend) but everything seems fine.

So be careful with these DIY AC recharge kit. I've seen the gauge swing a lot depending on how long the car has been running, and I didn't add or subtract any R134a. I think you do need two gauges to properly fill the car.


Ken 06 Exige

P.s. Man its nice having AC again. I took her for a ride and when I turned off the AC, I had to turn it back on within a few mins. I just hope I didn't damage the AC compressor..
 

·
Registered
Joined
·
2,339 Posts
If lotus spec 19oz I would have stopped right there regardless what the guage says. I think they are notorious for being off.
 

·
Registered
Joined
·
256 Posts
Discussion Starter #4
The refrigerant pressure must be within range. Too little or too much activates the "trinary" switch that turns off the compressor to prevent damage.
Michael
SirLotus, I noticed that my radiator fans are on, what seems like, "High" all the time now when I run my Ac. I saw that you had posted that if there is too much pressure that the fans will run "half speed", could this be whats causing my fans to run so hard?

Thanks
Ken
 

·
Registered
Joined
·
6,943 Posts
SirLotus, I noticed that my radiator fans are on, what seems like, "High" all the time now when I run my Ac. I saw that you had posted that if there is too much pressure that the fans will run "half speed", could this be whats causing my fans to run so hard?

Thanks
Ken
Ken,
From the service manual;

KH.5 - RADIATOR FAN & RE-CIRC. PUMP CONTROL
The two cooling fans are fitted beneath the radiator or (with a.c.) condenser/radiator package, and the coolant re-circulation pump is mounted below the header tank. Both the fans and pump are controlled by the engine management ECU using data provided by the engine coolant temperature sensor mounted in the back of the cylinder head.
The cooling fans are switched as a pair, and will operate at half speed (connected in series) when coolant temperature reaches 208°f on rise, and switch off at 201°f on fall.
The fans will also operate at half speed irrespective of coolant temperature if the a.c. is switched on and the compressor is running.
If coolant temperature rises to 217°f, the fans will switch to full speed (connected in parallel), reverting to half speed at 208°f.
The fans will also run at half speed, unless high coolant temperature dictates otherwise, when the a.c. is switched on and the compressor is running, or if the engine management system detects a fault with the inlet air temperature or coolant temperature circuits.
At road speeds in excess of 85 mph (135 km/h), equating to the fan stall speed, all fan functions are switched off.

A trinary switch fitted into the top of the receiver-drier senses the pressure of refrigerant and allows system operation only within a pressure range of 2 to 32 bar (29 – 464 psi) in order to prevent system damage from too high
a pressure, or from compressor oil starvation damage caused by too low a pressure. A third switching point is used to engage the two condenser fans at half speed at pressures over 17.5 bar (see also sub-section KH.5).
An additional safeguard is provided in the form of a high pressure relief valve in the condenser inlet pipe, which
opens at 38 - 41 bar.

Michael
 

·
Registered
Joined
·
256 Posts
Discussion Starter #6
Thanks.. Blew out some more R134a and the fans went back to half speed. Still have my check engine light on, I gotta get my OBD2 reader back from my pops and see whats going on. AC is still blowing cold.. I guess I really over did it.

Ken
 

·
Registered
Joined
·
2,376 Posts
Wouldn't the fans run at about quarter power?
 

·
Registered
Joined
·
433 Posts
Thanks.. Blew out some more R134a and the fans went back to half speed. Still have my check engine light on, I gotta get my OBD2 reader back from my pops and see whats going on. AC is still blowing cold.. I guess I really over did it.

Ken
For those who do not know, releasing (blowing out) this refrigerant contributes to global warming. While it would be illegal for me as an automotive professional, the very substantial EPA fines do not apply to private parties. This is both ironic and a source of anger in the professional air conditioning repair community.
 

·
Registered
Joined
·
256 Posts
Discussion Starter #10
For those who do not know, releasing (blowing out) this refrigerant contributes to global warming. While it would be illegal for me as an automotive professional, the very substantial EPA fines do not apply to private parties. This is both ironic and a source of anger in the professional air conditioning repair community.
This is a funny subject. I work in the HVAC industry for Siemens Building Technologies and we do commercial HVAC or building automation controls. A long time ago I was in a training class and they were talking about R12 and how its destroying the ozone layer or what not. Then the teacher put the book down and asked, "R12 is much heavier than air and it pours like water, the ozone layer is miles and miles above the earth, how is it getting up there to do damage?"

He said there is a conspiracy theory behind this as why R12 was outlawed. Dupont owned the patent for R12 and it was going to expire in 1995 and that it was and still is one of the best "Freon"s out there and its cheap to make. So about the same time this stuff was outlawed, they found their new Freon R134a is somehow better. DuPont is coming out with a new "Freon" that is even better for the environment and now they are talking about banning R134a. When asked how long it takes R12 to get into the Ozone layer, Dupont admitted that it would take thousands of years.

All of the ac techs that I know are more scared of the fines of getting caught. I've yet to meet one guy that thinks its bad for mother earth and they would all do it if it wasn't for Big brother watching. Driving around with a catalytic converter is far worse, IMHO.. which I'm guilty of too..

Ken
 

·
Premium Member
Joined
·
1,335 Posts
I guess you meen "without" a cat. But chemically speaking your spot on


Sent from AutoGuide.com App
 

·
Registered
Joined
·
572 Posts
I find it interesting that you were able to put the entire 20 oz AC Pro can into your AC system.

A month ago my serpentine belt cut through the high pressure AC line while I was driving. The sound of the AC line blowing gets your attention to say the least, and it filled the cockpit with smoke. Which I still don't understand since the line the blew was in the engine bay.

I purchased another line and replaced the bad one. I also used a 20 oz can of AC Pro. With the engine running and following the instructions I was able to put in 15-16 oz of refrigerant. My Ac system would not take more than that and the air was blowing cold in the cabin. I then topped up my other car and still have 1-2 oz left in the can.

:shrug:
 

·
Registered
Joined
·
433 Posts
This is a funny subject. I work in the HVAC industry for Siemens Building Technologies and we do commercial HVAC or building automation controls. A long time ago I was in a training class and they were talking about R12 and how its destroying the ozone layer or what not. Then the teacher put the book down and asked, "R12 is much heavier than air and it pours like water, the ozone layer is miles and miles above the earth, how is it getting up there to do damage?"

He said there is a conspiracy theory behind this as why R12 was outlawed. Dupont owned the patent for R12 and it was going to expire in 1995 and that it was and still is one of the best "Freon"s out there and its cheap to make. So about the same time this stuff was outlawed, they found their new Freon R134a is somehow better. DuPont is coming out with a new "Freon" that is even better for the environment and now they are talking about banning R134a. When asked how long it takes R12 to get into the Ozone layer, Dupont admitted that it would take thousands of years.

All of the ac techs that I know are more scared of the fines of getting caught. I've yet to meet one guy that thinks its bad for mother earth and they would all do it if it wasn't for Big brother watching. Driving around with a catalytic converter is far worse, IMHO.. which I'm guilty of too..

Ken
You apparently have received training for section 608 of the Clean Air Act that applies to Stationary Refrigeration and AC:
"EPA has issued regulations under Section 608 of the Clean Air Act to minimize the emission of refrigerants by maximizing the recovery and recycling of such substances during the service, repair, or disposal of refrigeration and air-conditioning equipment."
You are employed by Siemens, based in Switzerland. Europe is leading the way in changing over to the R1234yf refrigerant that is apparently replacing R134a. In fact, the European Union forced the issue so that the rest of the developed world (North America and Asia) is following along. Whereas the issue with R12 was destruction of the ozone layer, R134a contributes substantially to Global Warming. These are documented; your hearsay and old wives tales not withstanding. Also, "DuPont" made no such statement as you credit to them.
Basically you did not use equipment that would allow you to measure quantities and pressures or recover the overcharge of refrigerant. You just blew it out into the atmosphere with self serving pseudo justifications.
 

·
Premium Member
Joined
·
6,347 Posts
What is the total volume for the R134a in an Evora. Manual --> nothing
Boot or bonnet posting -->nothing
Doors -->nothing. Which means its probably RIGHT in front of me. So AC folks, do you think the sealant in AC Pro etc is a good thing or bad??
 

·
Arch. Project Manager
Joined
·
1,090 Posts
I believe the "sealant" in those recharge kits is just lubrication to "refresh" the seals(o-rings) and prevent oil starvation.
 

·
Vroom vroom
Joined
·
507 Posts
Then the teacher put the book down and asked, "R12 is much heavier than air and it pours like water, the ozone layer is miles and miles above the earth, how is it getting up there to do damage?"
It's always really tempting to feel like you are privy to some insider knowledge, but it's just not true. Your instructor may have been an excellent AC technician, but a scientist he was not.
 

·
Premium Member
Joined
·
6,347 Posts
Thanks, I looked up AC and didn't find it there. I looked in specs and it must have been right in front of me. .625kg is 22 oz. So if it took two 12 0z cans - the slight bleed one gets when unscrewing the cans , looks like I was probably pretty damn low. Might explain why I was using full AC at 75 degrees without Recirc. It felt like no AC at all on anything but full. I did remove and recheck gauge a few times and it read 30kpa at ambient 70 degrees which is considered good. Once again great forum.
 
1 - 20 of 31 Posts
Top