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AC is cool, but not "cold".

Discussion in 'Gen 2 Prius Technical Discussion' started by Ohem, Jun 8, 2023.

  1. Ohem

    Ohem Junior Member

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    Hi!

    I'm new to the forums and I'm not entirely sure if the post is in the correct category, if not I'd like to ask for the thread to be moved to the correct one.

    I got hold of a 2nd Gen Prius 2007 on the used market a few months ago, now pretty much everything works as intended but the AC needed to be refilled. I didn't want to spend several thousand Kronor (Swedish currency) so I bought a kit about 2 months ago that made the process easy and relatively cheap (approx $60). After recharging I had immediate results, ice-cold just as I like it. But over time, the "coldness" went from ice-cold to "cool". I got confused as to why it wasn't as cold and deduced it'd be from a leak and had reduced pressure, I had some remaining refrigerant left from the bottle I bought so I attempted to recharge it. To my surprise, the pressure was between 30-40 psi (I know I know we normally use Kpa but psi is so embedded in everything I read so I'm just going with that) and the sightglass next to the "High" pressure port show the current amount of refrigerant, but I'd like to have a second opinion: Do you observe any "bubbles" or anomaly in the sightglass?

    I tried linking a video to demonstrate but the forums won't let me, because I can't be too sure what's counted as bubbles or take notice of anything that'd diminish its job. It's on youtube with vMzpXsZPwio as ID (I had to be vague because of the forums restrictions).

    Do I have to vacuum and recharge it? I was considering replacing the pressure vents if so.

    Cheers!
     
  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    Save some time/money by following, reading posts, and watching videos by @lech auto air conditionin

    FYI : you're moderated until you've posted 5 times.
     
  3. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    A kronor is equal to 9.2 cents USD.

    Did you contact a dealership , say get a quote for AC recharge service?

    I went that route several years back; it cost me roughly $165 CDN, converts to about $125 USD, or $1360 Kronor.

    it’s still nice and chilly. :)
     
  4. Tombukt2

    Tombukt2 Senior Member

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    Is the 30 to 40 PSI you're seeing on the low side consistent in other words once the vehicle starts making cold air that 30 or 40 sits there and stays that way it doesn't pull down to 20 or 10 and then bounce back up to 40 and then pull back down to 20 or 10 it sits in that 30 36 range pretty steadily? This is kind of important in your sight glass if you start the vehicle with the pressure switch like disconnected and the air conditioning switched on But you don't hear the air conditioning compressor running get out of the car walk over to where you unplug the pressure switch now plug it back in while staring at the sight glass now you hear the compressor start but don't look away at the compressor keep looking at the sight glass Do you see the bubbles in the sight glass all of the sudden immediately clear up when the compressor clicks on? At that point the bubble should be pretty much gone and the sight glass is clear looks like you're looking at air almost? The only time you may see a bubble is when the compressor kicks off and then kicks back on when called for which could be very quickly if it's just been started That's what you should be looking for in the sight glass so when the compressor cuts out you may see a few bubbles... And then the system clutches back in or kicks back in and those bubbles immediately get squashed and it's clear You're fat hose should be quite cold. And the skinnier hose should be bringing the heat out of the car so it'll be warmer than the other at initial startup once the system is stabilized the cabin 10 minutes then both of the hoses can be similar in temperature but generally the little one will be hotter these cars are very common to have evaporator leaks that's the coil that's inside the car that the fan is blowing across to bring cold into the car If you have this it's thousands of dollars to tear the whole car apart and fix it It may not be worth it in some of these countries.
     
  5. pasadena_commut

    pasadena_commut Senior Member

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    Is the OP sure that the right sort of recharge was done? The Prius has an unusual AC system and also needs a very specific type of oil. But you don't want too much or too little.

    A/C oil replacement | PriusChat

    Be aware that the evaporators tend to spring leaks and it is a PITA to replace that as the whole dash must come apart. It failed in our 2007, it has failed in a lot of cars.

    Lech is the go to member of this forum for AC questions.
     
  6. edthefox5

    edthefox5 Senior Member

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    Evap Failed in mine too. You got a leak. Stop messing around your going to damage the compressor.

    Right now if you look in the sight glass and turn on the ac it will look like a snowstorm flowing real fast past the glass.
     
  7. PointCounterPt

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    What very specific type of oil? I've had a 2005 for years and have had no issues, but I'm wondering if I've done something wrong? Ironically, I just had my oil changed today.
     
  8. ChapmanF

    ChapmanF Senior Member

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    The oil in the A/C system is unrelated to the engine oil that you routinely change. The engine oil specs are in the owners' manual (and also on the engine oil filler cap).

    The A/C system is sealed, and normally the oil in there is just what they put in at the factory. Nobody messes with it unless the sealed system has to be opened or the stuff has leaked out.

    For the A/C, the important thing is an oil that won't damage the high-voltage electric windings inside the A/C compressor. Most cars don't have electric compressors so they don't have that issue, and the "usual" oil is no good to use in a Prius A/C. The Toyota spec for the Prius is "ND-Oil 11", which is kind of pricey and comes in metal cans and shouldn't be kept around long once unsealed.
     
  9. PointCounterPt

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    Ah, I misread what you were originally saying. I read it as the AC and the oil being 2 separate things. Thanks!
     
  10. edthefox5

    edthefox5 Senior Member

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    A Gen2 Prius is super common these days AC shops see alot of them. Spend the $100 at a good ac shop they will inject dye into the system and check for leaks. This is very very common. Do not go to the dealer for ac work!

    It may just be a loose fitting.

    Its so hot out now its impossible to drive any car with no ac especially the Gen 2 Prius if you roll the windows down the wind buffeting is intense.
     
  11. LEARNER

    LEARNER Junior Member

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    Spend some time watching Youtube channel T-Lech . He's also on here. Master of HVAC and lots of Prius videos. Many detailed insights he covers. Just search Prius there as there is no Prius playlist and many many of them.
     
  12. Tombukt2

    Tombukt2 Senior Member

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    So far on these old generation twos I haven't added any oil I also haven't replaced any components that would hold the oil like the condenser of the compressor yet when those things arise then a little bit of oil will have to be added I think now you can buy that electric compressor oil is pretty common so there's that and the freon is just 134a extremely common and there are substitutes and blends that are no problem for the electric compressor I'm running non-regular gas and two of mine with no problems they'll almost blow snowflakes out the vents no kidding My old 74 Corolla SR5 with the hang on air conditioner made by Denso would do just that.
     
  13. Ohem

    Ohem Junior Member

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    I had the car in repair at the dealership for a head-on collision with a deer, because of course I need the additional trauma and expense *sigh*

    I explained the AC situation to them, it's "cool" enough to be felt but not "cold" enough to be of comfort on hot days (i.e. I can't feel the difference between the setting 16C and Low). After the repairs, they stated they didn't find anything wrong despite me being specific about the 20-30 minute mark (from a cold start) where it's noticeable and the amount of air blown is reduced. So the car is fixed but the AC still leaves more to be desired, since they didn't find anything wrong with the AC I'm looking elsewhere for an AC service. I just hoped to save a few bucks in doing so, which is why I came here in the first place prior to my accident.

    I took a look at T-Lech but I couldn't find a video pertaining to my particular issue, because technically "it works" - just not as well as it did prior.

    It is possible there's a sensor regulating the AC? Some cars have pressure or temp sensors, but I haven't been able to find one in the Haynes manual. Or maybe it could be a bad drier? I guess it's just to suck it up and pay for a proper vacuum and recharge.
     
  14. pasadena_commut

    pasadena_commut Senior Member

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    Refer to the R134a chart here:

    How temperature and humidity affect the car's AC performance

    Use a quick reading kitchen thermometer to measure the vent temperatures. If for the given external temperature and humidity the vent reads less than the maximum value it isn't very likely that the dealer will consider looking for a problem. If the vent temperature is out of range for any observed temperature and humidity then there is definitely a problem and they need to address it. Note that that the vent temperature could be within range but one of the pressures way off, but the only way to know that would be to hook up some gauges.

    Since the car was in a front end collision it would probably be worth the effort to pull off the front bumper cover and inspect the condenser for damage. Maybe it is full of deer hair or deer blood or some other form of debris, which would reduce the system's efficiency. Or it might be bent. One of the refrigerant lines could also be bent or dinged - anything that restricts flow is bad.
     
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  15. Tombukt2

    Tombukt2 Senior Member

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    Do you see any bubbles in the sight glass ??? Get an assistant to sit in the car and from a zero running automobile with nothing on have the person start the car like they're going to drive it ready the car put the air conditioner on full blast low recirculate Don't set 72 put it on LO while he's doing that you need to be staring at the sight glass from the time that the button is pushed to turn on the air conditioner and you hear the air conditioning compressor click and start running Do you see bubbles in the sight glass form and then disappear or what do you see in the sight glass? That's the first thing to be thinking about. If you see bubbles when you hear the compressor click and start and be running and they clear up your pretty close to being decently charged now while that's happening the fat line silver aluminum with the gray or black cap usually marked with an l that's your low side that should be getting cold to the point where you want want to hold on to it very long Is that happening? If so it sounds like you're making cold now you need to go inside the car and the first thing I would do is drop my lower glove box by moving the little shock absorber letting the glove box fall down to my feet I usually hold it up with my foot so everything doesn't fall out of it and with my other two fingers I open the cabin filter door it's white withdraw the cabin filter Do you feel and hear the air blowing from the fan that sits just underneath it It should be moving air quite stoutly and probably is on high?. Is that filter full of doo doo mouse droppings hair stuff that would otherwise impede flow? If so knock it against your rocker panel and try to get all that nonsense out for now put the filter back in or when you pull the filter out did all of a sudden air start coming out the vents cold at a reasonable pace?. If not clean the filter reinstall it It needs to be there. There are damper door issues so you want to take your hand and feel down at the floor up at the defrost the vents that you want mainly to be working blowing straight at you is the air coming out more at the bottom of the top or somewhere else other than where we want it?. If so one of the servos may be bad and that maybe keeping you from putting the air where you want and the volume you want and then if the damper door that opens from recirculate to fresh is not up to snuff your system may be trying to heat fresh outside air constantly it'll be about 9 to 12° warmer when you're doing this fresh that is so those are some things to check really quickly.