about the pajero gen2 airconditioning mysteries and Q's

**j_carlop** · May 12th, 2006 11:06 PM

hi guys! about my import pajero 2.5, we are the 2nd owner of this vehicle and we don't have any problems regarding the conversion from right to left etc. well, the problem is that the aircon when switched "on", and were at cruising speed (i.e, expressway or an open stretch of road) the aircondition cools the cabin so well even when the sun is at it's peek.

But why when I encounter traffic jams, or when the vehicle was kept idling in a couple of minutes with the aircon "on", the blowing air will become warmer untill it doesnt have any more coldness left in it, so how I wish I avoid traffic jams especially during afternoons when the sun is at its peek, the heat really breaks up my head. but the coldness returns when I pour running water to the condenser and the radiator,

How could this happen? It seems that the onboard temperature gauge on the dash seems to follow, is it malfunctioning? sometimes it reads 41c even to 60c! when the reading is at 30c to 40c, the aircon performs so well, but during long traffic jams, it reads 50c to 60c! by this time the aircon is useless unless i pour water to the radiator and condenser. As far as I know, the monitor was supposed to monitor the outside air not engine temp.

Our vehicle was serviced regularly and we follow intervals of having serviced/cleaned the airconditioning system, the aircon shop adviced us that we can transfer the condenser away from the radiator underneat the vehicle so it will run cooler. Do u think guys this is a good solution? pls help me!

Tnx!

godspeed!

**HIFI** · May 12th, 2006 11:14 PM

Check the auxillary fans. AFAIK, there are 3.

Also, the evaporator may need to be overhauled...(in my case...it was replaced)

BTW, the on-board thermometer has nothing to do with the aircon.

**j_carlop** · May 12th, 2006 11:33 PM

tnx for the quick reply! u mentioned 3 aux. fans? I thought there's only one in big fan front of the radiator? were's the other 2 located? so its evaporator not condenser... tnx for correcting, I will try your suggestion. tnx!

**OTEP** · May 12th, 2006 11:45 PM

First thing you check are the auxillary fans. Yes there are three. But only two are for the a/c. The large one behind the grille and a smaller fan behind the front bumper. The third fan is the intercooler fan mounted underneath the intercooler. It is not related to the a/c system. Fan repair at Mang Mario costs Php 400.00/fan SRP (so you have an idea of the cost). A replacement fan motor (surplus) costs around Php 1,800.00 SRP. Malfunctioning aux fans will cause rise in cabin temp since there will be no airflow over the a/c condenser.

The next thing would be the compressor. When the compressor is not making enough pressure (therefore it is not 'compressing' enough), you will also experience the same symptoms (cool when driving, hot when idling).

In my case, the compressor was shot (very low pressure reading even on the HIGH pressure side of the system). I had Mang Mario put in a new one. Cost of the compressor and installation was Php 4,900.00 SRP. He was also the one that sourced the compressor for me (maybe I'm just too lazy to find my own). 6 months warranty. I think its a good deal.

Since there is a/c cooling at speed, I don't think your evaporator (the cooling coils behind the glovebox) has any problems.

External temp gauge only reads correctly at highways speeds when there is sufficient airflow over the sensor. Otherwise, it also reads radiant engine heat and exhaust heat from other vehicles.

Transferring the condenser (from in front of the radiator to a lower level) does not sound like a real solution. The system is designed to work perfectly in its present location. There are thousands of Pajeros on the roads with cool a/c's with the condenser in the stock positon. Find the real problem. Not do a ghetto fix you might regret later on. Besides, lowering the condenser will make it more prone to picking up road debris and it could get damaged should you decide to venture off-road.

Hope that helped.

**j_carlop** · May 13th, 2006 04:29 PM

Tnx for the info sir Otep... Of all the things you mentioned, A/C compressor and aux fans, I had my aircon mechanic checked it and they all work so well, I also had my compressor replaced a year ago, but I will have the compressor checked to another aircon shop just to be sure.

I suspect the condenser maybe is the culprit because when I pour water over it, the coldness returns, the big aux fan is working so it gets sufficient airflow but still, it tends to get hot during traffic jams, do you think condensers can be overhauled rather than replaced?

Also Sir Otep, I also want to ask the small fan you mentioned under the intercooler. I found it and noticed that when I start the engine, the fan does'nt rotate. Is it normal? they told me that it only comes "on' when the engine needs more boost from the turbo, is this true?

Tnx again for your important infos.

**OTEP** · May 13th, 2006 10:05 PM

Check if the compressor still has sufficient compression on the high pressure side. Compressors not working at their peak are still considered working, although they cannot cope up in some situations (e.g. idling).

Have you checked your smaller fan? A malfunction in any of these two fans may cause the system to have excessive line pressure which can destroy the compressor. So even if you replaced the compressor but did not ensure both fans are working, the new compressor has a high chance of destroying itself again.

The condenser is a non-moving part. Refrigerant just goes through it (much like water in a radiator). About the only time these things are replaced is if they have a puncture. Condensers also have to be cleaned with pressurized air from time to time.

Have you checked the expansion valve? Of course, this will entail removal of the evaporator. Expansion valves are usually checked during cleaning. Some 'taga' aircon shops even replace them at every cleaning session (easy money).

The IC fan is operated by a thermo-sensor. It only operates when the engine is hot.

**levi** · May 14th, 2006 11:03 PM

I have the same problem. First thing I did was to change the compressor ( original bnew ) bec the surplus I installed only lasted for a few months and the coldness is not the same. I had a general cleaning also including replacement of expansion valves. It was very cold until my aux fan broke down. It gets hot during traffic but gets cold when Im moving. After fixing tha aux fan (upper and lower) the aircon is back to normal. Its as cold as bnew even at traffic. Even if the aux fans are functioning they may not be 100% working or it might be eratic causing the condenser to have high pressure preventing the freon to freely flow. It could also be the lower fan which is very hard to check and that the high pressure happens at the lower part of the condenser. It will also affect the flow of the freon.

**ruelsdcz** · May 17th, 2006 06:36 AM

sir otep, i hv the same prob with my pregio. this summer lang po nagloko but during nite time or makulimlim superb po ang lamig nya. 8months pa lang po ung compressor ko na 508. i hv 3 aux fan (1 radiator, 1 front condenser,1 rear condenser) and all in good running condition. My AC tech check the H and L pressure. I hv no prob on my HEAT Temp lagi cyang normal. He told me dapat H=40 and L=280, but in my case mataas ang HIGH and normal ang LOW. He sprayed water on my condenser and add some more accelaration, suddenly the H pressure went down. Di daw po kayang hold ng condenser ko ung HIGH kya hindi gaanong makalabs ung heat from my evaporator kya hirap lumamig pag sobrang init ng panahon. MY option will be add one more condenser or fabricate a big one with 2 big aux fan.

Sir, can you give me some idea about this. and sir im from subic saan po ba ung place ni mang mario? do u can he can help me?

ty

**OTEP** · May 17th, 2006 09:48 AM

Mang Mario has a thread in the WORKSHOP forum. Use the search function.

High pressure is usually caused by an inefficient fan (it may be working, but it might be too slow). Pero madami ding ibang possible causes iyan. If everything were within spec, your a/c should work fine with no design changes.

**j_carlop** · May 22nd, 2006 11:42 PM

hi guys! my problem regarding the aircon of my jdm pajero was solve... for a cost of 20 pesos... yup, i had inspected personally the lower aux fan you mentioned and found outthat its electrical wires were cut, I reconected it with the help of an electrical tape, the fan works again.

after almost a year of finding out what is the real problem, it is finally solved, Now the aircon works as cold as bnew even in heavy traffic jams and very hot afternnons!

well guys tnx for the info...

god speed!