I have a 98 honda civic ex and the air conditioning is stuggling. I put guages on the high/low pressures and got 225 psi on the high side and 8 psi on the low side. What would cause this big pressure difference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scoobyghost &raquo;</TD></TR><TR><TD CLASS="quote">I have a 98 honda civic ex and the air conditioning is stuggling. I put guages on the high/low pressures and got 225 psi on the high side and 8 psi on the low side. What would cause this big pressure difference.</TD></TR></TABLE>
Is the low side line warm or cold?

 

Its not cold but its definatly not hot. I can hold the low side but i can't even touch the high side.

 

Run a dye through it man.

 

I don't think there is a leak I think theres something else wrong. Its cold at night and when the car is on the highway but when ever its hot outside or the car isn't moving it doesn't cool at all.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scoobyghost &raquo;</TD></TR><TR><TD CLASS="quote">Its not cold but its definatly not hot. I can hold the low side but i can't even touch the high side. </TD></TR></TABLE>

EDIT&gt; Make sure your condensor fan is working before doing any of this.


The low side line should be cold. Try reving it up to about 2k. Does the low side drop to vacuum. That would indicate a restriction in the system. Check the entire high side of the system for cold spots (hoses, lines, condensor, rec/dry) which would indicate the restriction. If no cold areas are found you probably have a defective expansion valve.

 

Where is that located on a 98 honda civic?


Modified by scoobyghost at 6:54 PM 6/13/2005

 

if it had a leak it would be low on the high side as well as the low side. check for a clogged low side line you will see the line freezing up) or a malfuctioning txv.

 

I also had a audi mechanic also tell me about the txv. He said that it might be broken. Is the txv the same thing as the expansion valve? Where is it located on a 98 civic ex?


Modified by scoobyghost at 11:39 PM 6/13/2005

 

Well I found where it is located(behind the glove box) but when I change it and evacuate the system do I need to replace anything else? I've heard you should replace the drier but is it necessary. Thanks to everyone for the help.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scoobyghost &raquo;</TD></TR><TR><TD CLASS="quote">Well I found where it is located(behind the glove box) but when I change it and evacuate the system do I need to replace anything else? I've heard you should replace the drier but is it necessary. Thanks to everyone for the help.</TD></TR></TABLE>

It's always a good idea to replace the filter/dryer whenever you service the system, it'll save you hassle down the line if it's almost toast. Does the condensor fan work? Make sure the fan works before you do any work, it sounds like that could be the problem... make sure the condensor air path is not blocked either, and that the fan is pulling the air the right way.

 

A bad condenser fan won't cause 8 psi suction pressure. You would see higher than normal suction/discharge pressures because heat isn't being rejected from the system.

Feel the lines at the drier. They should both be warm. Feel the liquid line at the firewall (small pipe that passes through firewall and feeds the evaporator). Should be warm. If that's good then look at the txv. The powerhead element on your txv could have lost it's charge (the capillary tube leaving the top of the txv with cork tape around the bulb). When the txv loses it's charge it thinks the evap coil temp is -10 degrees. The txv doesn't open because it thinks the coil is satisfied and doesn't need more refrigerant. That explains the low suction pressure.

Any time the system is opened the drier should be replaced and the non-condensables should be removed. Driers remove moisture from liquid refrigerant and prevent acids from forming in your system.

 

I didn't think the fan would cause a pressure difference like that. Thanks for the help eda6. I will let you know what happens.