I have a 95 GS-R with about 130K miles on the clock. On Sunday I took the car out for a drive and the A/C starting blowing hot. When I would slow down or pull up to a traffic light it would blow cooler (coolest at dead stop). When on the freeway it would feel like the heater was on.

I checked the temperature gauge and it was at about halfway. I parked the car outside and notice that in my garage there was a small puddle of coolant on the mat around where the front of the car would have been.

After a while I restarted the car and it was blowing cool again, until I started driving, then it warmed up. Does anyone have any idea what could be causing this?

 

go check if you have a leak on coolant.. ??134..
or did you remove the heat shield of header?
also check the A/C belt
It also have a chance of the A/C radiator start getting stuck..
Could go to a shop and have your compressor check..

It takes 2 weeks for me to figular out its my A/C rad having problems and blowing hot air..

 

it sounds like you are low on freon, go to a shop and have them check it out. then come back and let us know, as far as antifreeze causing your AC to get hot, ive never heard of that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LSVTECJay &raquo;</TD></TR><TR><TD CLASS="quote">it sounds like you are low on freon, go to a shop and have them check it out. then come back and let us know, as far as antifreeze causing your AC to get hot, ive never heard of that.</TD></TR></TABLE>

yeah I mean freon.. the "H whatever 134" thingy
when you run out of that, the header is extremely close to the A/C radiator, with 800 degrees C. you know..

 

I had the same problem this weekend. Was cool at idle but got warm all of a sudden. When I got home I checked my freon and the pressure was were it was supposed to be. It did however shoot up to 60 psi when raised the rpms a little bit. But, after that, whenever I revved it, it would drop to 40 psi. Can a shop check you a/c rad, to see if it is ok?

 

it is not an AC radiator, its ur condensor

 

Is it a way for them to check it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95GS-R &raquo;</TD></TR><TR><TD CLASS="quote">
After a while I restarted the car and it was blowing cool again, until I started driving, then it warmed up. Does anyone have any idea what could be causing this?</TD></TR></TABLE>

my guess is a restriction in the expansion valve or orifice tube, whichever your car is equipt with. the restriction would cause a lower than normal pressure in the evaporator causing temperatures to drop below normal. the drop in temperature causes the surrounding air to freeze, and block the fins of the evaporator, blocking off cool air flow into the cabin. when you let the car sit, and restart the car, the ice would have melted, allowing cool air to flow until the freezing air clogs the evaporator again.

that's my guess... but i haven't figured the warm-on-freeways, cool-at-idle thing yet.

 

how do you find out where the obstruction is at?

 

Took it to a shop and had it looked at.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister6 &raquo;</TD></TR><TR><TD CLASS="quote">go check if you have a leak on coolant.. ??134..
</TD></TR></TABLE>
This is fine actually.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
or did you remove the heat shield of header?
</TD></TR></TABLE>
I actually did a while ago trying to stop a rattle. Is this an issue? Should I put it back on?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
also check the A/C belt
It also have a chance of the A/C radiator start getting stuck..
Could go to a shop and have your compressor check..
</TD></TR></TABLE>

The radiator on the car was toast. Had it replaced at the shop, and air is blowing nice and cold now. I have no idea what the correlation between the radiator going out and the heat changing with speed is, however.

 

well first, you'll have to "see" if there is a restriction in the expansion valve, and the only way to do that short of removing it from the car is to use a pressure gauge. what you want to do is look at the low and high side of the system when the system is operating. the low side pressure gets lower (if i'm remembering correctly) while the high side gets higher. shut off the system, and what you're looking for is how fast both sides return to the same resting pressure.

i.e. the resting pressure could be 70psi depending on where you live. at rest, with the a/c off, both high and low pressures will be at approx 70 psi. when the a/c is activated, the low side drops while the high side rises in pressure. when you shut off the a/c, both sides equalizes to 70 psi, and what you're looking at is how fast they equalize to 70 psi each.

in reality though, i don't think most techs, even at hond will know exactly unless it's printed in a repair manual. the ones with the most experiences working on honda a/c systems will pretty much be the only to know...

BUT, before you even pursue this possible cause, you need to know if the symptoms i described even relates to your situation.

- a clogged expansion valve, or clogged anything in the a/c system will simply cause the a/c to NOT work AT ALL. at any time of day at any weather, etc.

- a restricted expansion valve may cause freezing of the evaporator. the symptom is the a/c working and then the air warms up. when you shut off the a/c for a period of time, the a/c will work again, but warms up again. it does NOT have anything to do with driving on the highway or idling... at least not that i know of or have experienced.

- leaking coolant should have little to no effect on the performance unless it's really low or something.

- any problems you have in the rest of the a/c system (seized compressor, low refrigerant, clogs anywhere, moisture in the system, etc) would cause CONSISTANTLY warm air or not-so-cold air. it wouldn't fluctuate.

i'm sure i'm missing something, but i had a phone call that distracted me a little