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high pressure on High when over 200 RPM Pages: 12

goth on Wed April 01, 2009 12:34 AM User is offline

Year: 97
Make: chrysler
Model: sebring convertible
Engine Size: 2.5
Refrigerant Type: r134a
Ambient Temp: 95
Pressure Low: 20
Pressure High: 300
Country of Origin: U.S.Minor Outlying Islands

Ac works fine at Idle speed but if RPM Increase above 2000 RPM pressure on high side starts climbing fast to above 300 psi and then high pressure switch cut compressor off. I checked refrigerant charge and its OK it is not overchraged. Any Suggestions what else to check?

GM Tech on Wed April 01, 2009 9:11 AM User is offline

Is the primary cooling fan running? The one behind the radiator? Is there a pusher fan that is not kicking in? Typical "not enough air across condenser scenario" when head pressure spikes enough to experience HPCOs (high pressure cut-offs)

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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......

NickD on Wed April 01, 2009 10:03 AM User is offline

Another and a consistent problem is a condenser/radiator loaded with bugs. Also can find tons of debris between the condenser and the radiator. Can't have AIR conditioning without AIR flow.

goth on Wed April 01, 2009 12:07 PM User is offline

Thanks for the Help !!!!!! Awesome forum!!!!!! Regarding the fan, It only has one Fan that runs at two different speed, I can see how the second speed kicks out, but even when this happes the pressure on the high keeps rising until it cuts, The only way I can bring it down is throwing some water at the condenser it will lower it right away, Other thing I have noticed is that when the weather is cold it will work with no problem. I am wondering If the pressure rises because of the condenser not being able to cool it down, or becuse there is a problem with the expansion valve or because of the compresor genretaing more pressure when RPM increase?

Sorry for the First Reply I new to this forum.

GM Tech on Wed April 01, 2009 1:29 PM User is offline

The test for poor condensing due to poor airflow is to spray water on condenser- you have done that--- said it helped-- soooooo...look for shrouds missing, bugs, dirt, blockages,-- is fan turning the right direction?-- sucking air into engine compartment?

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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......

goth on Wed April 01, 2009 1:35 PM User is offline

The fan is rotating the right direction, I already looked for dirt or bugs but looks clean, It looks like I will have to take the condeser apart and flush it. Do you know hos does the compresor regulates Pressure or flow when RPM increase?

TRB on Wed April 01, 2009 2:27 PM User is offlineView users profile

Any cold sections on the condenser? Any sealer added to the system that you know about?

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Contact: ACKits.com

goth on Wed April 01, 2009 3:24 PM User is offline

TRB..-Do you mean Cold sections in the hoses? It was cold on the On the Low side right after theH block Expansion valve and evap. R3egarding the sealant I have not added any , But this problem starte after a replacement of the compresor, expansion vlave and drier/filter, The first Thing I tought was that it was overcharged so I tried to pull some gas out and I could notice oil coming out as orange foam So I am wondering if whomever replace this put more oil than what it should and if excess of oil will cause pressure to rise?

TRB on Wed April 01, 2009 3:33 PM User is offlineView users profile

No cold sections on the condenser, IE blocked passages. This style condenser could be plugged with debris if not flushed correctly from a compressor failure. Little more information on how thew repair was done may help us determine what areas to look into.



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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

goth on Wed April 01, 2009 4:21 PM User is offline

I see what you mean, I need to check for cold areas to identify where is plug? Regarding how the repair was done, This is my brother car he took it to an AC repair shop las month and the guy replace the compressor the drier and the expansion valve, my brother saw when they vacuum it and he told me after they vacuum they added compressor oil by the low side port (I dont think this is right), IT didnt work my brother took it back and the guy told him that there was aproblem with the compressor so he took it out sent it to warranty, and after a couple of days pu it back on, they vacum charge oil the same way (trhu the low side port), and it barely cooled at night, so next morning my bother took it back and the guy told him that it didn´t had enough refrigerant so he added more, it worked for about a week but beacuse the weather was below 80, last week we reached 100F and the compressor started to cut, so my brother took it back and the guy told him that the problem was the engine cooling system, He did not believe it since the gage on the cluster doesnt show it that way and the car works perfect, so he came to me, I do have experice with industrial AC, so I hook my gages and realize that the pressure on the high has climmbing when he goes over 1500 RPM, the system work fine when IDLE (20 psi on low and 200 on high), but as soon as he increases RPM pressure on the high climbs and cuts the compressor, first thing I tought it was that the system was overcharged so let some gas out and noticed oil coming out As well, It didnt help at all, so now I am wondering is there too much oil in the system and if so is this causing the pressure to rise? Other thing I am wondering is how is the pressure and flow regulated when the RPMs increase?

TRB on Wed April 01, 2009 4:53 PM User is offlineView users profile

Do a search on scroll compressors. Lot's of info here and the web in general on the operation of a scroll.

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Chick on Wed April 01, 2009 5:42 PM User is offlineView users profile

Adding some, letting some out, none of which is good. You do need the correct charge in there. Have the system evacuated and recharged Properly after checking what the others advise. But you have to know that the right amount is in the system, or it will drive you nuts!..Hope this helps..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

TRB on Wed April 01, 2009 5:58 PM User is offlineView users profile

It also sounds like debris and oil have been left in the system from the original repair. No telling how much oil is in the system or if debris is causing this issue. Only one way to get back on track in my opinion, flush, new drier, evacuate and recharge. Was the compressor a new unit or a re-manufactured model?

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com


Edited: Wed April 01, 2009 at 5:59 PM by TRB

iceman2555 on Wed April 01, 2009 7:20 PM User is offlineView users profile

Scroll compressor generally produce tremendous debris fields when they fail. The inlet of the condenser becomes a great location for this material to accumulate. At idle the efficiecny of this compressor is lower and as RPM increases the efficiency increases....an increase in discharge pressures....a restricted condenser....an severe elevated discharge pressure....and the PRV releases.
A suggestion would be to address the possible source of the excessive pressure....the condenser. While there, why no insure that the system lubrication specs are up to par. Remove the TXV and flush the evap, clean the a/c hoses...if equipped with mufflers....then the lines need to be replaced.


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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



Edited: Wed April 01, 2009 at 7:33 PM by iceman2555

TRB on Wed April 01, 2009 7:27 PM User is offlineView users profile

Ice that image needed to be larger!!!

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

iceman2555 on Wed April 01, 2009 9:52 PM User is offlineView users profile

Larger...you want larger...should have seen it the first time....another one of those full page...scroll to see it all things......

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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

Matt L on Wed April 01, 2009 10:18 PM User is offline

Good thing you resized it then. One of the scrolls is broken in that image.

TRB on Wed April 01, 2009 11:04 PM User is offlineView users profile

Quote
Originally posted by: iceman2555
Larger...you want larger...should have seen it the first time....another one of those full page...scroll to see it all things......

I was being sarcastic as I fixed the image for you! I don;t mind and will add it to your next bill. Rate will be the only amount I know which is what my IT guru charges, sorry pal union says I have to charge it!

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

iceman2555 on Wed April 01, 2009 11:39 PM User is offlineView users profile

I got the sacasim....but still should have seen the first 'resize'.....quite large. But then still learning.
What size best fits?

MattL you are truly correct....the movable scoll is 'broken'...and this happens with the replacment when the system is not properly prepared for the replacement.

Spoke with a 'tech' in 'Arnoldland' this PM.....has replaced three scrolls on a late model Honda CRV.....two condensers.....two TXV's, numerous flush procedures...and the systems are still failing. when A suggestion was offered to aid in facilating this repair....his response.....why...never had to do this before.....never mind that the systems have changed so completely that it is impossible to adequately clean the debris from this type failure. He responded that since neither 'identafix nor IATN' recommended the procedure....that my suggestion had not merit.
Sure hope he is successful with his next attempt....and sincerly hope he takes the advice of 'identafix (spelling ?) or IATN to use only the 'second generation' OE Honda compressor for this repair......that should be great......love their warranty.....
"Bring a new check....get a replacement part"!!!!

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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

TRB on Wed April 01, 2009 11:55 PM User is offlineView users profile

800 x 600

The one I edited was like 3200 x 2200.

Responding to your last comments ICE, if it's not clean, it really matters little if it is OE parts or aftermarket in my opinion.

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

bohica2xo on Thu April 02, 2009 2:57 AM User is offline

1) Oil coming out of service port as "Orange Foam". I wonder what is in the system for oil?

2) Repaired. Replacment compressor, add oil > replace again, add oil again.... Must be about a litre of oil in it by now...


Time to go back to square one. Tear the system down, and flush the evaporator & plumbing to bare metal. Obviously the current compressor is in decent shape, still able to push 300psi.

The condensor? hard to say, without knowing exactly what happened to the original compressor. That condensor is not simple to flush either. I would replace it rather than fool with it. If you decide to flush it, you will need a LOT of compressed air to get all of the flush back out.

B.

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"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.

NickD on Thu April 02, 2009 6:44 AM User is offline

Started off with either fan or bug problems, now looks like a major overhaul is required, not only tons of oil, but more likely, tons of air in the system as well, plus debris. OP did say the compressor was replaced, guess GMtech and me assumed it was done right, always a second time.

mk378 on Thu April 02, 2009 11:40 AM User is offline

Yes, too much oil will cause excessive pressure and general poor performance. Almost certainly there is too much oil. Scroll compressor systems don't require much oil; also when you buy a new compressor it will often come with some oil in it. (This oil should be removed and replaced with fresh oil).

If the first compressor suffered internal failure (it wasn't merely leaky or had a clutch problem), the condenser is going to be blocked with debris like the others pointed out.

goth on Thu April 02, 2009 12:06 PM User is offline

Thanks For all the Help!!!! Great forum!great people! After all of the sugestion I am going to flush the complete system to get rid of oil and debris and and get back replace the drier, I saw a label under the hood with refrigerant load .875 KG, and amount and type of oil, I believe is PAG 10 8 oz, My only question is how to get rid of oil and debris inside the compresor????

TRB on Thu April 02, 2009 12:21 PM User is offlineView users profile

Compressor" Drain the oil from the compressor. Buy extra oil and use it to wash out the oil and debris on a work bench. No way to really flush a compressor so all you can do is add some clean oil turn the hub of the compressor by hand and hopefully wash out as much old oil and debris as possible.

Compressor Type
2.5L (SOHC) Sanden MSC105-CVS Scroll

Compressor Belt Deflection
2.5L (SOHC)
New 9/32-5/16" (7.0-8.0 mm)
Used 5/16-11/32" (8.0-9.0 mm)

System Oil Capacity
2.5L (SOHC) (3) 5.7-6.4 ozs.
Refrigerant (R-134a) Capacity 24.7-26.1 ozs.
Use ND-8 PAG Refrigerant Oil = PAG 46 which I suggest using a DEC PAG if possible!!!

System Operating Pressures
2.5L (SOHC)
High Side 129 psi (9.1 kg/cm2 )
Low Side 27 psi (1.9 kg/cm2 )
With ambient temperature at 77°F (25°C).


-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

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