To Hot to drive car now (AC Issues)1994 24V 164 super

alfettaparts · #1 (**permalink**) 11-21-2006, 02:56 AM

I know many of you are heading into winter however in oz atm its going to be a stinking hot summer and I cant even drive my 164. Its a black car with black interior and its just to hot as the air conditioning is not putting out alot of cold air. I have gone over many things and fixed a few bugs but the system still pushes out warmish air so I just wanted a few ideas on where to go next. Heres whats happened so far.

Air con cold on average day.
Air con not cold enough on hot day.
Filter out for testing and max air flow.
Air flow exceptional ie:very strong blower motor.
No low speed fan when air con turned on - fixed faulty resistor and dodgy wireing by auto elec now fan turns on when AC is turned on.
Inside out/side air flap stepper motor not working - fixed so vent opens and closes with switch and placed seal around flap so that it seals when closed.
Inspected components - all seem ok and are 134 compliant and there is no air in system through sight glass.

That about sums it up.

So im curious will re-gassing the system help if the gas in the system at the moment is 'dirty' or 'old'? Should i replace the device with the thin copper pipes that are said to block up?
I believe the compressor and condensor to be all good as when the system was operating without the fan running there was a large and universal heat build up over the condensor so much so that i couldnt hold my hand against it after only a few minutes running. This was also true of the reciever dryer. Now the fan is running all this heat is drawn away even from the reciever dryer at the rear of the bulk head yet the air is still not cold enough.

Its got me stumped where to go next really so any suggestions would help especially any order of elimination that i could use rather than chasing my tail.

Cheers
Dean

**Alfisto Steve** · #2 (**permalink**) 11-21-2006, 06:59 AM

Have you put a set of gauges on system to check low and high pressures? I would suspect if compressor working that Freon level is low. You can add freon to get low pressure down so cooling will increase and high pressure should come down to if radiator cooling fan working correctly.

You can also disconnect low speed cooling fan resistor wires and jump it's brown and blue wires together to have high speed radiator fan for summer weather that helps cool condensor better.

jeffb99tx · #3 (**permalink**) 11-21-2006, 07:39 AM

My 1994 164 also has a difficult time keeping up with the Texas heat. In addition to regularly checking the condition of the AC system, I have done the following modifications. They are fairly simple and have a modest effect.

1) Installed a heater core shut off valve in the engine bay. During the warm months, I turn off the radiator fluid to the heater core. Since the seals around the flaps inside the car are fairly old and do not seal all that well, this helps keeps engine heat out of the AC hot/cold mixer area.

2) Had the windows tinted as dark as legally permissible. This helps keep some of the solar energy out of the cabin area. I used the basic 3M brand window tinting and it cost about US$110 for the tinting service. I have heard from others that upgrading to a very high quality window tinting film has a very good effect of keeping the interior cooler. Some of the high quality films keep out something like 90% of the solar energy. When I looked at the higher cost films, the tinting job was going to cost something like US$425. I skipped on the upgrade as I was being hit with other 164 repair bills at that time.

Overall, having the AC system pressure tested about 3 times a year helps make sure that it is operating at maximum efficiency. However, sitting in highway traffic in 100 degree summer heat really takes its toll on the AC system. Although moving at highway speeds, the AC system is adequate during the peak summer months. I hope this helps you out some and good luck with the system.

Cheers,

Jeff
Dallas, Texas
1994 164 LS

ChazzyD · #4 (**permalink**) 11-21-2006, 07:43 AM

H/C shut off valve: Murray #84707 Shut-Off Valve for 3/4" heater hose, found at local auto parts store.
Charles

alfettaparts · #5 (**permalink**) 11-21-2006, 01:29 PM

Thanks guys. I saw that heater shut of valve on the digest.
I am curious about one other thing and that is, should the AC core inside the airbox, where the dust filter sits, get cold when the AC is running. Im imagining this should be ice cold to touch if the system is working correctly. That is Im assuming where the heat is drawn from the air as the air passes through.
Cheers
Dean

**Alfisto Steve** · #6 (**permalink**) 11-21-2006, 01:44 PM

Yes it should be cool as that is evapaorator which takes the cabin heat and transfers it to the freon for a run through the condensor to cool car down.

Put those gages on system to see what it is doing.

**goats** · #7 (**permalink**) 11-21-2006, 03:21 PM

Hi Friends

The performance of the 24v AC is OK IF and ONLY IF it is working properly. It is very sensitive to exact oil and 134a charge levels, cleanliness of the condensor and evaporator, high and low pressures, and air flow from the fan and at speed over the condensor.

Are you sure the compressor is engaging? You should hear it click and then hear the engine groan a little as the increased load is put upon it. If all you hear is a click, check freon level and trinary switch. As Steve says, get a set of guages and hook em up and get some hig/low side pressure readings. Make sure your bulb seal on the false firewall is not leaking and drawing hot engine air into the system. Always a good idea to replace the drier as once it plugs up flow is reduced and cooling suffers

It can sometimes help to instrument the air temp at the vents and spray a fine mist of water onto the condensor whilst the fan is on. If the vent temps drop a lot, that MIGHT tell you that the condensor is plugged or internally dirty.

If you wanna learn about car AC go to www.ackits.com and look on the information forum.

alfettaparts · #8 (**permalink**) 11-22-2006, 02:57 AM

Thanks guys very helpfull. Im going to have the system regassed next week and see if that sorts things out. I have owned the car for five years and it has never been done. It is still charged but to what extent i have no idea. I wont replace any of the compents yet as the car has only done 140 000 kms approx 90 000 miles so they might be ok. Benica motors havnt got any gas atm so i have to find someone else to do it which i always hate as non alfa people seem to be able to break, burn or butcher what ever part of the car they decide to look at. Ill see how it goes.
Thanks again
Dean