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2006 Saturn Vue Not Blowing Cold

mmgargol on Fri May 25, 2012 12:53 AM User is offline

Year: 2005
Make: Saturn
Model: Vue
Engine Size: 3.5L V6
Refrigerant Type: R1348
Ambient Temp: 100deg F
Pressure Low: 80
Pressure High: 195

Hello all,

I am having a cooling issue with my 2005 Saturn Vue. The car has the Honda 3.5L V6, and we are right about 115K miles on the car. The cooling capacity seems to be quite diminished from previous years. I am not the primary driver of this vehicle, my wife is, but I have noticed a lack of cooling capacity.

I put my gauges on the car, and with an ambient temp of approximately 95-100 deg F, the car at idle, and the AC on the Low and high side pressures were 80psi and 195psi respectively. The duct discharge temperature was right around 80 deg F.

With the engine reved to 2000 RPM the pressures would go to approximately 50psi on the low side and 250psi on the high side. The duct discharge temperature was measuring 55 deg F. When the AC is on one cooling fan is running continuously, the secondary fan will come on based on the engine temp. They both feel to be moving a lot of air across the condensor. I also inspected the condensor, and it is clean and in good condition. I also at one point directed my swamp cooler with the fan operating only into the grill of the car, there were no major changes in the high side pressure.

I have been driving the car lately, as my wife's commute is much longer and the AC in my car works better. I have the temperature sensor in the duct, and while driving, constant speed on the freeway the discharge temperature will remain pretty steady at around 55-60 deg F, but the moment I come up to a red light the discharge temperature will move rapidly up to 75-80 deg F.

My initial inclination is the compressor may be on it's way out and not moving refrigerant efficiently, but it will drive the pressure up at higher RPMs, it has gone over 300-320psi at around 2500-3000 rpm, but the low side still did not drop much below 50psi. This got me wondering if the Expansion valve may be malfunctioning. With this particular model valve, I do not see a sensing tube on the outside, so I am not sure how to test it.

Any thoughts or assistance is much appreciated.

Thank you,

GM Tech on Fri May 25, 2012 7:10 AM User is offline

I had a 2005 Saturn Vue a month ago- same issues but not as bad as yours- it ran at 50 psi suction at idle (you need about 25-35 suction to cool worth a darn.. it did cool better at higher rpm as yours does-- but those scroll compressors need rpm and lots of it..I ended up replacing the cheapest item- the TXV. and got about 10 psi lower suction- now 40 psi suction at idle- still not good-- I told owner next option is a new compressor- but he opted to keep his money in the bank, not in making scroll compressor makers rich..

I advise anyone who needs cool air, not to buy a Saturn Vue..

Good Luck

The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

mmgargol on Fri May 25, 2012 9:57 AM User is offline

We have had the car going on 4 years now, and it actually has been a great AC system. It is just recently we are having the issues with it not working well. It used to blow cold the moment you turned the AC on. The compressor and TXV are my two prime suspects, but i just wanted to make sure I wasn't missing anything.

I took it to a shop for an AC check up the other day, the only thing they said they could do was evacuate and recharge the system with the correct refrigerant weight, and that isn't guaranteed to fix it, but it was guaranteed to cost me about $200. For that price I could almost pick up a recovery machine off craigslist and a cylinder to weigh out what is in there and put in the correct charge myself.

bohica2xo on Fri May 25, 2012 11:15 AM User is offline

I have an 07 Vue with the same engine. The cooling is great here in the desert. Search the board, I am not fond of scroll compressors, but this one is doing it's job well.

I clean the condensor every 30k miles. With 62k on it now it will get cold enough in the summer to make the wife bring a sweater. I have never added refrigerant.

Your pressures indicate an aging scroll compressor. 100k miles? Well performance is obviously heading downhill. The TXV can't control evaporator pressure all that well, but it seems to be working well enough.

When you do get to the point of replacing the compressor, spend the extra 180 bucks (with the site sponsor) and buy a new condensor. That scroll has been shedding metal, that is where the performance has gone. The condensor in newer systems is the primary filter. Buy a new compressor too.


"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

mmgargol on Fri May 25, 2012 2:34 PM User is offline

When we bought the Vue, it had 60K on the clock. We now are at right around 115K. It has worked great for the last few years. But this year is leaving much to be desired. There are no indications of leaks, and my original thought after looking at the pressures was the compressor may be on its way out. Pretty much the moment you pull up to a red light the air starts to blow uncomfortably warm.

What about the evaporator? do those degrade, or catch metal filings the same as the condensor?


mk378 on Fri May 25, 2012 5:05 PM User is offline

It may be a little undercharged. The second fan is probably cycling on pressure, so you can't say that it is full just based on the high side pressure. You could try topping up yourself-- don't add more than one 12 oz can though, and stop if high side starts to climb even with both fans on. If performance is not restored or it gets worse, then you can assume the compressor is tired. The condenser and drier should catch almost all bits of metal, of course having the condenser clogged up will reduce its performance.

mmgargol on Fri May 25, 2012 6:36 PM User is offline

I added a little bit of refrigerant the other night. Around 8-9oz. I'm not sure if the improvement I saw was becasue the refrigerant or because the ambient temp had dropped a little bit.

I don't think the fan was cycling due to high pressure, as the second fanwould come on and off with while the ac was still running and the pressure gauge never rose above about 260psi with the engine at 2000 RPM.

My other car is also GM, a Cadillac, and it's a 2005, much less miles though. I hope I don't run into a double whammy with it starting to go as well. It's older, but less miles.

Looks like I may have to just bite the bullet and redo the HVAC in the car (bangs head against desk)

Thanks guys,

bohica2xo on Sat May 26, 2012 4:29 PM User is offline

It is really not that bad to replace the parts needed to return it to as it was when it left the factory. A/C systems are actually very reliable. Your system has gone over 100k miles with no service and only 8 ounces of oil in it. So if you put $1000 in to a repair that is less than a penny per mile. If you put tires on every 40k miles they probably cost more.

Have you done the 100k service on the engine yet? If not the compressor is easy enough while you are there.

Be glad your other car is not a Pontiac - then you would have two orphans parked in your driveway.


"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

mmgargol on Tue May 29, 2012 12:38 AM User is offline

I'm not too worried about the work. The compressor and condensor seem pretty readily accessible, as well as the TXV. It's just a matter of time right now I actually just did the timing belt, water pump, coolant lines and spark plugs this last weekend, just a little overdue. I will start gathering the parts for this job next. Will I need to flush the system since the compressor didn't fail? If so, I would need a shop to do that, as well as recover the refrigerant. I don't have the tools for that. Although now may be a time to buy some more tools just for the job ha ha.

Thanks for all the help guys, much appreciated. I figure if I get it up and running and it gets me another 115K out of it, I should be on to another car by that time

Edited: Tue May 29, 2012 at 12:49 AM by mmgargol

bohica2xo on Tue May 29, 2012 1:17 AM User is offline

Well if you just did the timing belt, this is a walk in the park.

You will be close to doing a "firewall forward", so the only thing to flush out will be the Evaporator & some lines. The TXV, Receiver / Dryer, Compressor & Condensor will all be new parts.

Flush the remaining parts to bare metal, and then you can put the factory oil charge in it. Some new O rings at the peanut fittings & you are ready to evac & charge.

Gut your old TXV & add a couple of features to it. A large bore hose (1/2" or bigger ID) on the suction side of the evaporator long enough to reach a catch can (5 gallon bucket) on the floor near the car. For the high side of the block, add an air fitting or hose to connect to your compressor. Bolt the old block on & blast the flush through the Evaporator.

When you install the new TXV pay attention to the thermal sensor. Buy some heat sink compound to fill the sensor well with so you get good heat transfer to the thermal sensor. If the well is dry the system will freeze the evaporator.


"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

mmgargol on Tue May 29, 2012 3:07 PM User is offline

Well I don't have an air compressor, so this may be part of the job that a shop will have to do. I may get everything in, take it to have the evaporator flushed, and then finish the rest at home after a flush.

Edited: Tue May 29, 2012 at 3:08 PM by mmgargol

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