I think im freezing..!

[elwesso]

I think i have a case of the AC working too good... I think what happens is after a while of highway driving (say 15-20 mins) the evaporator starts to ice up... it seems like something blocks the air flow as it drastically reduces... However, if I put it on econ for like 5 mins or so, the airflow resumes and I can put it back onto AUTO....

Also, when I put the hood up after a longer trip the service valve low side (on the firewall passenger side) is generally covered with ice, and it always leave a nice puddle of water. Today when I checked it, after a couple of mins there was a STEADY stream of water coming from the drain.....

Any ideas???? Could the system be "overcharged?"

[maxnix]

No to overcharged, yes to undercharged, or especially dirty evaporator coils.

[elwesso]

I cleaned the evaporator as best I could earlier this year (took a toothbrush to it, got all the crap out, etc).... I will probably have it checked soon.....

[qship96]

expansion valve

[FarFetched]

I think it is dual presure switch. Icing up evap is caused by. Could be faulty a/c pressure switch. I don't think undercharging would do it. You can check evaporator for bubbling (to little-overcharge -bad, too many undercharge(leak)- bad).Check a/c working pressures. Cheers!

[maxnix]

I don't think undercharging would do it.

You think incorrectly, sir! Near specification charge will be percieved as very efficient and the evaporator coil temp will be sub-freezing, thus allowing icing.

The refrigerant is the heat transfer mechanism. When it is at specification, it will never allow the coils to get cooler than 34° F. And it will actually transfer away the heat is the cabin air more effectively than when undercharged or overcharged (coils always too hot).

It most likely is not the evaporator valve as it is cooling.

Without high and low side pressure data, we are just urinating upwind anyway.
Modified by maxnix at 1:19 AM 5/6/2006

[elwesso]

This is true.. IT works good enough and I dont mind switching to econ for a sec to let it defrost..

Ill print some pages out from the FSM and have them check the pressures.... might consider jusdt investing in a manifold gauge myself

[FarFetched]

Quote »Without high and low side pressure data, we are just urinating upwind anyway[/quote]Any AC work w/o running pressures is wothless. We can speculate till winter when natural AC effect takes place I know import A/C systems designed differently than Big Three. However, my experience with cycling systems that what happens. Q45 system is a constant dudy system so rules might be different. Best bet would be recover, evac, vacuum pull, charge with proper amount and test unless working pressures are correct according to ambient temps!However, it could be expansion valve.
Modified by FarFetched at 2:29 PM 8/28/2005

[elwesso]

I drove home today, roughly 80F with average humidity for the area (>50%<70%) and I didnt experience this problem...

one thing that seemed to make it worse (let me know if this makes sense) is I removed my factory intake... Everyone knows about the little air horn behind the grille, well I removed all that and that may induce more effective cooling at highway speeds to the condensor?

[FarFetched]

It is a possibility that condenser isn't getting good flow. That would diminish overal a/c perfromance when ambient tems are higher. Did you retrofit to R134 or it awas always R134?

[elwesso]

It is a possibility that condenser isn't getting good flow. That would diminish overal a/c perfromance when ambient tems are higher. Did you retrofit to R134 or it awas always R134?

if anything the condensor is getting BETTER flow!

BTW, its R134 from the factory,and lots of new components on there (as per Fred)

[3Q Jay]

might consider jusdt investing in a manifold gauge myself

doit!

or, bring her out to cali. i'm setup for r-134a now! 20 micron pump, mani set, oil injector, pag46, even a 'refrigerant' [really a 1 gram resolution kitchen] scale.

[DAEDALUS]

Costco sells the R-134a now. $200 for 30 lbs. I paid $60 less than 2 years ago for the exact same stuff. Could be a good investment, like R12 was.

[elwesso]

Yeah too bad I didnt buy about 1000lbs of R12 back in 1990.....

R134 is the standard so i dont think we'll see a huge increase in price anytime soon.

[DAEDALUS]

R-134a has been the standard for 10 years. Yet its cost has gone up 233% in 2 years--same brand, same seller. I don't know what forces are driving its price, but I wouldn't presume they suddenly don't apply.

[elwesso]

R-134a has been the standard for 10 years. Yet its cost has gone up 233% in 2 years--same brand, same seller. I don't know what forces are driving its price, but I wouldn't presume they suddenly don't apply.

Good point, however my point was that it wont be jumping up as much as R12 did when it was banned, but then again, i could be wrong.....

[elwesso]

I was thinking about starting another thread, but thought id bump ths one instead if there are any more comments on this problem before I take it in to have it vacuumed and recharged.

[Q45tech]

R-134a will be banned [legal production limited] soon......2009 per EU regulations. US needs to restrict non licensed sales ASAP. it is still officially classified as a global warming gas.

In many ways it turned out to be worse than R12.

R152a and R744

[elwesso]

Thanks for that info, tech..... I may buy some R134a as an investment..... Plus ill definitely need to have some for the Q...

Tech, do you have any thoughts on this [my problem with the AC]?

[Q45tech]

Not without pressure vs temp vs rpm graph.Probably from improper vacuum down too much moisture mixed with R134a.

[Q451990]

R-134a will be banned [legal production limited] soon......

Sounds like I need to make a trip to Wal-Mart for a couple of cases soon!

[Q45tech]

It's you [collective you] that has caused all the warming, I'm giving the Polar Bears your address. Couple of cases?

[qship96]

It's you [collective you] that has caused all the warming, I'm giving the Polar Bears your address. Couple of cases?

LOL- my q has only needed 5-6 OUNCES of r134 added at the 10 year mark,since it left the factory new! what would you do with all that stash?

[elwesso]

Sell it for a lot of money in a few years.

[Jesda]

Polar bears are pretty nice if you take the time to get to know them.

Fewer and fewer places are carrying R12 now. A local shop is now offering Freeze12 to customers as an alternative. Dealer still has R12 for $78 (was $60 back in 03).

[Q451990]

It's you [collective you] that has caused all the warming, I'm giving the Polar Bears your address. Couple of cases?

I'm a pack rat... what can I say It's funny - this stuff was supposed to be environmentally friendly... just like MTBE... maybe we can go back to the more efficient R-12 now?

Heath

[Q45tech]

Dealer still has R12 for $78 (was $60 back in 03).

T3 charges $50 per pound, we need to raise our prices...........you should hear people whine about $120.

[Q451990]

Polar bears are pretty nice if you take the time to get to know them.

You know, you're right! This little fella showed up today with his own can of 134a - wanted to make sure he stays cool during his journey to the south!

[Aussie Q45a]

Th

This is true.. IT works good enough and I dont mind switching to econ for a sec to let it defrost..

Ill print some pages out from the FSM and have them check the pressures.... might consider jusdt investing in a manifold gauge myself

Wes, can you do me a big favour and do a self diag.test and let me know what code/s you get? Thanks Greg

[elwesso]

just went and checked my codes, and i got no malfunctions... MY HVAC system works (according to the computer) normally.