2002 Nissan Patrol A/C Problem

[OTEP]

Recently my a/c doesn't seem to be as cold as before. I dropped by the local a/c shop and they saw one of the big rubber a/c hoses (the one passing over the air intake) having oily residue on it. So they say there might be a leak.

I was in a hurry and needed to use the car so I just ask them to top it off. They did. However, only the rear a/c blew cold. The fronts were not blowing as cold.

The shop tells me it could be an expansion valve problem. They prescribed, replacing the leaky hose, a new drier, a/c cleaning, and 2 new x-valves. The total bill rounds up to around Php5k (includes labor and materials) but will take a whole day to do so I just set an appointment.

This evening, I was using the rig and the front a/c seems to blow cold again. It only loses efficiency in hot weather, maybe? Or did the R134 top off work?

Do you think the shop's diagnosis is correct? Anybody had a similar problem with their rigs before?

[Horsepower]

hmm. how is it possible that the rear can blow cold air and the front can't?

Maybe something is just a bit loose.

[yapoy86]

the shop is correct with their diagnosis.. have your hose replaced and your expansion valves.. expansion valve is very critical in airconditioning system.. it makes sure to release the high pressure freon gas to the evaporator so it will not starve and maintain cooling efficiency..

in your case, the expansion valves are not able to efficiently react to the high pressure especially during a hot day where the compressor can build too much pressure.. your expansion valve got stuck close (front AC) starving your front evaporator.. your rear AC expansion valve is working properly that is why it got all the high pressure freon making your rear colder than the front AC

[gabo2000]

pareplace mo yung aircon hose. kaya nawawala o humihina ang lamig kulang lng karga.

[bambino]

if your temp mode setting is steady at max cold and or the mode door actuator if it's electronic controls is not malfunctioning ,then that must be the expansion valve causing it.

[afrasay]

Doc Otep,
Nangari na sa akin yan dati. yun hose na yun madalas masira due to vibration of the engine. yun front and back difference eh dahil sa expansion valve. there are two in our patrol, one for each front and back evaporator. so if the front goes kaput you are left with only the rear cooling the cabin and vice versa. medyo nagbabara na yan siguro pero pagnatuluyan yan di na lalamig yan. yun aircon shop near our place tried to blow compressed air and even soak the valve in gasoline pero pag clogged siya talagang throw away na. may times din din na maganda buga ng mist ng expansion valve parang injectors ng diesel engine pag di na tama spray pattern di na siya efficient. HTH

[s_quilicot]

Ilan po ang condenser ng patrol?

TIA

[miked]

usually isa lang ang Automotive A/C condenser...nagkaiba lang sa size..sa evaporator 2 kagaya ng patrol ni sir otep..funny thing, may nabasa ako sa inquirer a few months ago wrt nissan's A/C systems written by a columnist (i forgot the name)....notorious daw sa pagkasira.

[gincammapala]

Mga kapatid, makikiride lang sana ako dito kung OK lang...
nagpalinis po ako ng AC. Palit drier worth 150 at expansion valve worth 350 at oil daw na worth 50 pesos na nilagay sa bote ng mineral water na maliit...mga walang tatak po. yung mga pinalitan ko pong piyesa ay may mga tatak po. after po magpalinis, mejo di na gano kalamig yung AC ko.. malamig pero di na gaya talaga nung dati na malamig talaga! di tulad dati na masakit sa balat yung lamig.
tapos pag nakatodo yung temp,di sa nagootomatic. naka taas lang yung menor.parang di niya mareach yung lamig siguro. ewan ko po. binuhus-buhusan pa ng taga shop yung condenser para mag automatic.
bago po yung freon and my compressor is 507 daw. sanden ata yun.. help naman po kung tingin niyong dahil sa mumurahing expansion valve ang prob. yung pinaitan kong expansion valve is "eaton" or "eyton" ata... im not sure...
pinacheck ko sa ibang shop,sabi nag hhigh pressure daw.
ilagay ko lang daw muna dapat sa gitna yung temp at obserbahan at dapat daw maganda yung expansion valve na binili ko at mejo kulang din daw ng karga ng freon...
sabi dun sa shop dapat mga nasa 750 yung expansion valve.
yung drier ok lng daw kahit yung umurahin.
backyard tropa lang po ang naglinis ng AC ko. ayaw ko na ibalik sa kanya.
my ride is 1191 corolla small body.
thanks guys!

[OTEP]

Update lang po. Ginawa na ni Mang Mario yung a/c (medyo matagal na pala ito). Palit lang ng expansion valve and drier, AFAIK.

Then recently, changed the front evaporator kasi may leak na.

The thing blows cold now.