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Volvo v70 poor performance at idle Pages: 12

echerbst on Mon July 08, 2013 12:12 PM User is offline

Year: 2000
Make: volvo
Model: v70
Engine Size: 2.4
Refrigerant Type: 134
Ambient Temp: 85
Pressure Low: 50
Pressure High: 175

I have a 2000 Volvo v70 that is driving me nuts. I replace the evap, compressor, and condenser all for leaks. Replaced orifice tube and accumulator. I believe it an issue with the aftermarket condenser not being efficient as the oem unit. When driving down the road ac works well. At idle temps climb and outlet temp is 60 at best. If raise engine rpm will cool slightly better but high side temps climb to 275 and low side will still never get down below 50. System had correct charge and amount of oil. I vacuumed and charged several times to be sure all air and moisture was not an issues. With a water mist test on condenser at idle cools to 45 degrees and pressures drop right where they should be 25/140. The fan is working fine. Before changing the parts system worked fine at idle.
Any other suggestions apprectiated before I put an OEM condenser in it.

fireguywtc on Mon July 08, 2013 2:50 PM User is offline

Yeah, is the fan operating properly? I believe on your model of car the electric fan should be on when the AC is on. You may be getting good air flow over the condenser when driving but not parked without a working fan.

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1970 Ford F250 4x4
2007 Ford F350

Edited: Mon July 08, 2013 at 2:52 PM by fireguywtc

echerbst on Mon July 08, 2013 5:49 PM User is offline

Yes cooling fan is running on high with the A/C on.

iceman2555 on Mon July 08, 2013 9:38 PM User is offlineView users profile

Could be a condenser problem....what type unit was used, who produced it and what is the construction material?

That being said....the pressures stated are a bit off for the ambient temp. How was the system recharged...by hand or the use of a R/R machine or a method to weight refrigerant? A buck 75 is a bit low for 85 degrees and if the evap is not cool the outlet temps/pressures will be a bit higher. Where did the "should be pressures of 25/140" originate? These do sound a bit far fetched at the posted ambient temps.

Adding water drastically enhances heat transfer and will result in a drastic temp/pressure drop. However, the first inclination would be the charge rate.

Check the condenser for temp drop. At idle with a properly charged system/properly cooling engine system the temp drop would be app 22-26 degrees. Unless this is a PF Sub cooling unit and then one could add about 10 + degrees for the extra cooling of the secondary condenser.

Post a bit more info.


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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

AutoCool on Wed July 10, 2013 2:50 AM User is offline

Does your car have manual AC or automatic? It sounds like you have a problem with your stepper motor Look at the one on the passenger side that has an actuator arm, check and see if the arm popped loose from the flap on the evap box. Also if you have ACC, you really need to check trouble codes, if your outside temperature digital display is wrong then the system will NOT work properly, if your sunlight sensor on the dashboard isn't working properly then the systemn will not work properly. Take a flashlight and look at your cabin temp sensor beside the radio. If the fan inside isn't running or if there's lots of dust on the sensor then it won't work properly either.

Trouble codes will tell you if there's a bad "lying" sensor.

When a V70 with ACC is working right, (and set on recirc and low temp) your center outlet temp should swing back and forth between 40.6F and 47.6F that's your evap temp sensor kicking on and off. Even at idle. If your high side pressure is running that high as you wrote, it may be improperly charged, air in the system, or somebody sold you the wrong orifice tube. . I believe you have a sticker on the passenger side fender that shows refrigerant capacity and it lists for several models. Maybe you filled it with the wrong charge.

Only problem I've seen with aftermarket V70 condensors are corrosion issues here in the land of salty winter roads.

There was a design change in 05/2000, what is your chassis number?

That must have been a fun job replacing the evaporator. Have it read for trouble codes, big risk that a wire snapped somewhere and you're mixing outside air and air off the evaporator or even air running across the heater core. It's a Swedish car, the heater capacity is enormous.

echerbst on Fri July 12, 2013 4:54 PM User is offline

It was charged with correct amount off sticker with a robinair a/c machine. It has no trouble codes already checked that. I will check the condenser temp drop to see if that is the issue. I replaced the complete line with the orifice tube with OEM Volvo part. It cools fine when driving down to 45 degrees so I don't think I have a blend door or air mix in the HVAC box that is the issue. The evap on these is not a fun job but I have done enough. At 8 hours very easy to make money on, but this is my car that the nanny uses to cart the kids around in so that was a freebie. Only two parts that are not oem are the condenser and compressor. Thanks for the ideas Ill check the condenser and only other thought was the compressor was not working good a idle speeds but the pressures were close to what should be at 50/175.

echerbst on Sat July 13, 2013 12:37 AM User is offline

Checked the temp. drop across the condenser and it was 25 degrees, 160-135. Evap inlet and outlet temps were 54 degrees with outside temp of 78 degrees which is low. If I bring the rpm up it will begin to drop temp to 40's. So I have a feeling that the compressor output at idle speeds is the issue. At speed when cruising the temp is also in the 40's. The spray test on the evaporator just makes the temp drop because the added cooling makes it more efficient.

iceman2555 on Sat July 13, 2013 5:16 PM User is offlineView users profile

The posted info for the condenser appears to be within an acceptable range. The inlet temp appears to be a bit high...but this could be contributed to under hood conditions and heat levels. It was stated that when the condenser was flooded with water the temps dropped drastically. Try a mist of water over a period of time. If pressures and temps appear to be more in line with cooling performance, this could be an indication of a possible electric fan motor issue. Perform a amp draw test on the fan.
The evap temps are in line with the stated vent temps, so it does not appear to be an internal air flow/heat problem. Where the evap inlet and outlet test performed with the doors open or closed? These temps would be more inline with an 80-85 degree ambient temp and doors open, with doors closed this temp should be much lower after a short operational time. Evap outlet temps would indicate the evaporator temp and can be compared to vent temps. Normally a difference of 5-7 degrees dependent upon vehicle model.
Typically a compressor that is capable of producing 275 psi of operational pressures is not a concern. Heat loads increase drastically during idle/non movement conditions and vent temps are expected to rise. Proper condenser cooling during this phase is essential to maintain temps.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

echerbst on Sun July 14, 2013 10:57 AM User is offline

Just did some more testing today.
Outside temp is 85
At idle low side is 45 / high side is 198
Evap temp is 58 degrees, vent temp 60 degrees.

If I raise rpm to 2k low side comes down to about 42 high side climbs to 300psi with minimal temp change in he vents. I put a huge fan in front of the condenser to see if that would change anything and it does not. Water mist will drop temps a few degrees but large amount of water will make temps drop 10 degrees with rpm up.

I am at about wits end here it used to be an ice box like 45 degrees vent temp at idle.

Iceman I appreciate all of your input. Do u think there is a high side restriction before the condenser that is not moving enough refrigerant into the condenser that was about my only idea I have left. Unless the fucked up the condenser when they built it and it not flowing though all the cores.

Dougflas on Sun July 14, 2013 6:00 PM User is offline

If you have a restriction before the condenser, you will have a drop in temperature before the condenser. Measure your discharge temp at the compressor and then at the condenser. What about the possibility your replacement condenser is not as efficient as the original? Does a water mist drop the vent temps?

Edited: Sun July 14, 2013 at 6:02 PM by Dougflas

iceman2555 on Sun July 14, 2013 6:38 PM User is offlineView users profile

What type condenser is this. Is it a parallel flow or a 6mm pic? Is it constructed of aluminum or brass/copper?
Are you capable of adjusting the charge rate or do you require a tech for this service. Some condenser mfger's will suggest a additional charge rate for their condensers. This is normally app. 2 oz. How old was the service machine for this repair? Was this charged with virgin refrigerant or with recovered....asking because of the remote chance your system could be contaminated with 'bogus' refrigerant.

If you have the ability to service the system...try adding a couple oz to the system and retest.

Good luck.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

echerbst on Mon July 15, 2013 3:56 PM User is offline

I have a robinair machine. Only few years one 37400 machine. Use it all the time on customer cars. Machine has new filters and fresh tank of 134 on it. I did put a 1.2 pounds in the system instead of 1.63 and it seemed to cool a little better. Ill check all the discharge temps. Aftermarket parallel flow condenser painted black aluminum. Ill put a little more refrigerant in and see if that makes a difference. After I had running a while the temp drops across the condenser were not 25 degree as they were prior dropped to around 10 degrees so I have a felling it's a condenser issue. I put a huge fan in front of it too and that did not change anything. Water makes temps at evap drop to 45 like they should be.

iceman2555 on Mon July 15, 2013 8:32 PM User is offlineView users profile

Was the AC machine charging hoses equalized after completion of the recharge? If not, this could represent a undercharged system. Also, the temp drop of 10 degrees typically indicates a system undercharge or inadequate condenser cooling. A drop of 20 degrees is considered an acceptable drop for a properly charged system. Different systems may offer additional temp drops and this is a design feature of the OE's system.
The problems encountered tend to point to either or possibly both of these conditions. If possible obtain a good temperature tester with thermo couplers. Check this tool, DT222 @ www.ueitest.com. Requires the purchase of additional probes and clamps, but is a very good temp tester. Sorry Tim, did not see or locate one on your site. This will enable a true temperature test of metal surfaces and present a more definite test procedure. Infra Red/Laser are not comparable for proper AC diagnosis. The temp range maybe be several degrees out of spec or as much as 100 degrees out. We have tested multiple units over the last few years and discovered that there is a vast discrepancy between touch probes and the 'toy' ray guns.
First inclination would be that the system is undercharged? But be sure to test the engine/radiator/condenser cooling system completely.
The stated undercharge is a serious amount of refrigerant. 1.2 = 19/20 oz. 1.63 = 26 oz. The system MUST be charged properly to perform a proper diagnostic procedure.
Good luck,

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

echerbst on Mon July 15, 2013 9:37 PM User is offline

I have some thermocouples I can use with my fluke meter to test. I always equalize the hoses. The Volvo only has a low side service port. High side pressure ready with scanner. Ill play around with the charge. It has the correct amount in now at 1.63 pounds. I just put in 1.2 after I initially filled three times with the correct charge and had pressures a little high to see if it made a difference in performance.

webbch on Thu July 18, 2013 2:56 AM User is offlineView users profile

Really? Only a low side service port? I have a 2002 V70 that I haven't connected up to yet, but I see a cap on the condenser which I assume is for the high side and then a cap on the low side line about midway between the radiator and the firewall on the passenger side (in a rather awkward location to make the connection of course). I'm assuming those caps unscrew to reveal service ports underneath, but admit I haven't removed them to see yet.

echerbst on Sat July 20, 2013 4:27 PM User is offline

Yeah the 2001 and up have a high side port on the condenser through the core support. Need an extender for those. The 2000 only has a low side.

iceman2555 on Sat July 20, 2013 5:04 PM User is offlineView users profile

There is no need for a high side service port. Simply measure the temperature of the discharge line (compressor to condenser) use a press/temp chart and convert to pressure. Measuring the discharge side offers a more exact profile of system operation than liquid pressures.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

webbch on Sun July 21, 2013 2:04 AM User is offlineView users profile

Quote
Originally posted by: echerbst
Yeah the 2001 and up have a high side port on the condenser through the core support. Need an extender for those. The 2000 only has a low side.

An extender? Are you saying it's an R-134a fitting, but too deep to access with a normal coupler? Where to get such an adapter? Didn't notice something like that on sponsor's site.



echerbst on Sun July 21, 2013 3:21 AM User is offline

I have on I got somewhere a while ago. Just a coupler hose and male fitting on top. U can read the high side pressure on the scan tool also

webbch on Sun July 21, 2013 1:00 PM User is offlineView users profile

Sorry for the link, but couldn't find a comparable product on sponsor's site...
#1
#2
Do you think #1 link would work, or heck, just a straight coupler?

webbch on Sun July 21, 2013 11:51 PM User is offlineView users profile

Just for kicks, I went out and put my plain jane high side 134a coupler on the high side port of my 2002 V70 XC. No problemo, no extender needed. My coupler is this one

Edited: Sun July 21, 2013 at 11:52 PM by webbch

webbch on Sun July 21, 2013 11:56 PM User is offlineView users profile

Quote
Originally posted by: iceman2555
There is no need for a high side service port. Simply measure the temperature of the discharge line (compressor to condenser) use a press/temp chart and convert to pressure. Measuring the discharge side offers a more exact profile of system operation than liquid pressures.

Provided you are 100% certain what refrigerant is circulating in the system....But I suppose you have a low side port to connect up a refrigerant identifier. Everyone IS using an identifier, right?? ;-)

Also, it will preclude you from doing a sealant identification on the system, as that hooks into the high side port as I recall.

Edited: Sun July 21, 2013 at 11:58 PM by webbch

webbch on Thu July 25, 2013 2:45 PM User is offlineView users profile

BTW, just picked up the "professional" 134a couplers, which allow me to valve off the flow at the coupler. Very nice feature, but the 90 degree attachment to the hose gives me just slightly less vertical clearance for reaching the recessed high side port on this car. Just barely enough that I needed a taller coupler specifically made for these recessed ports. A straight coupler would work as well.

Hooked up a scanner to the car and it'll display the high side pressure. Gauge set was about 200 psi, sensor read 180, so about 20 psi difference for the record.

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