2009 Pontiac G3 AC Probs (DIY diagnosed and repaired! With pics)

[xintersecty]

I'm gonna spend the rest of the day researching and then I think I'll have a crack at it.

Watch this space...

Take pictures and share on the forum. And don't forget to check your fan inside the car

[The_Limey]

Yep. I'll do that when I replace the cabin air filter. One quick question: if I'm removing moisture from the system via vacuum is it still crucial I replace the dryer?

Thanks ever so much for your help, xintersecty (or should that be Origin?). Sometimes it helps just to have a gentle shove in the right direction.

[xintersecty]

Yep. I'll do that when I replace the cabin air filter. One quick question: if I'm removing moisture from the system via vacuum is it still crucial I replace the dryer?.

You have to replace the dyer. It's contaminated. They need to be replace ever so often as moisture get's into the system. Or trap the moister that got introduced in the first place. Here is a short read:
Air Conditioning Dryer

A longer read and much better:
Auto Air Conditioning - Replacing your auto A/C compressor

I took my name as it's mathy and kinda cool. I will admit I suck at math. I got to differential calculus and my f'ng head exploded.

[The_Limey]

So today was a long old day and I'm left feeling like I didn't really get anywhere. Two things really held me up: removing the serpentine belt and the radiator. Despite using all the magic words at them, I still had to go and make a cup of tea before I managed to get anywhere with them. I took a shedload of pictures, mostly to remind myself where stuff went, so I won't bore you with them all. The short version is, I now have a car that looks like this:




and a pile of bits that looks like this:



I'm still not convince whether the compressor works or not. There's no signs of leaks anywhere having visually inspected everything I've pulled out so far. I went to empty the PAG oil out of the compressor, turning it by hand over a bucket, and there was nothing in there. Not a drop. Which worries me. I'm gonna flush everything out tomorrow and look for metal particles in the solvent. The expansion valve looks clean to me, but I'm not really sure what I'm looking for other than obvious metal particles:



I drained the coolant and had a moment of panic when it came out an orange colour. I thought it was rust before a bit of research revealed these cars come with Dex-Cool which is orange.



On a slight positive note, when I removed the cabin filter it was filthy, so there's at least room for improvement there. I've read a lack of air flow across the evaporator can hinder cooling performance, which makes sense.



Tune in for part 2 tomorrow...

[xintersecty]

Very good. Sometimes the expansion valve is just a orifice, a fixed sized hole. That allows the liquid to expand as a gas and works as a throttle.

No oil in compressor is bad, very bad. Plan on getting a new one.

You are doing great.

[The_Limey]

Well, here's the thing. I have a new one and a new condenser. Should I just fit them and be done with it?

[xintersecty]

Well, here's the thing. I have a new one and a new condenser. Should I just fit them and be done with it?

I would. Granted it's more money, but having a happy Air Condition Wife is priceless. Considering the condenser fins are beat up, replacing it is not a bad idea. Make sure you replace as many of the O-rings as you can on the different hoses too. I remember just buying a box of random sized o-rings, and I swapped them around the last time I did an AC job.

[The_Limey]

I'll probably go this route. I'm gonna hook the compressor up to a 12V source to engage the clutch and see if I can get any discernible suction/compression from it. Guess I should probably change the expansion valve to be on the safe side, too. I've got a 4 Seasons (I think) o-ring kit so I'll change everything when I reassemble it.

EDIT:

So the evaporator/cabin fan works.



The compressor also seems to work:



although when I turn it by hand there's a bit of scraping (probably due to it being devoid of any oil) and comparing compression to the new part I have, it's no where near as strong. With the ports plugged, the new one is significantly harder to turn by hand.

I'm just going to bite the bullet and change the compressor and the condenser. I'm off to buy a new expansion valve, too. More updates later tonight, hopefully.

[The_Limey]

Sorry for the lack of an update recently. Things haven't gone exactly according to plan. So, after stripping everything out and fannying about with the compressor, I decided to just play it safe and replace it along with the condenser/dryer and expansion valve.



And all the radiator plumbing back in place with new coolant added:



Next, I hooked this bad boy up to some shop air



and set about flushing all the pipework through



which left me with a bucket of solvent that looked a bit like this:



Having discovered that removing the evaporator would entail the entire dis-assembly of the cockpit, I got a little creative and flushed it out in situ.



Next up was fitting the new compressor with a fresh dose of PAG46 oil:



All bolted back in and time to tackle the idler pulley. I employed a bit more leverage this time round and it slipped on much easier.



So, with all the nice shiney new AC parts installed, it was time to pull a vacuum. And this was where things stopped working out for me. It turns out my father-in-law's shop compressor was 20 years old and had probably never seen a service and, as a result, was a bit leaky.



This leak got progressively worse until the motor on it was starting to smell like burning oil and it could barely sustain 70psi.



I decided to put it out of its misery and unplugged everything with a vacuum barely below 22inHg.



Feeling a little dejected that I'd come so far and couldn't finish the job, I popped down to the local garage to see how much they'd charge me to finish the job. They quoted me $99 which coincidentally was the same price Harbor Freight were charging for this single stage vacuum pump:

Electric Vacuum Pump - 2.5 CFM

I put the car aside after spending three full days on it, and contemplated my next move. Whilst weighing up the options, my father-in-law makes a call to a friend of his who has a machine shop built on the side of his house that would put most commercial garages to shame. Turns out he has a shop compressor with more than enough oomph to drive this crappy venturi type pump I have, and says if I drop round tonight with the car he'll give me a hand finishing the job.

Fingers crossed!

[PoisonIvy]

Good luck! I hope it works out tonight.