Tx Valve For Air/con

[proRB88]

hey guys/girls

I have been told by some of you the reason my air/con is so temperamental is because my "TX valve" is not regulating the pressure or something a long those lines.

i was wondering before i start searching for a air/con specialist to charge me an arm and a leg. Could some one please give me an idea of the amount of work involved in fixing the TX vlave, and what sort of money ill be looking at, to get it done. Also if you have any1 that you would recommend, i live on the Gold Coast.

Cheers,

Vlad

[t_revz]

just re-read your original post. could still be the tx valve but another thing, on the left of the steering wheel there is what looks like a vent in the dash, pretty sure ive heard that tube/sensor being disconnected will make temp increase.just make sure its not loose etc. if someone could chuck some gauges on and have a look while its playing up then they would know if its the tx. not sure on costs as i only do mining work but prob 50-100 for valve 1-2 hours changing valve and another hour or so to vac,charge and test.

maybe just get someone better than the last person to put gauges on and diagnose, preferably when faulting

[Muff]

start by checking your gas.

got gas???

if so does the ac drop in and out??? then eventually stop working????

90% of air con related problems are due to a faulty tx valve. ive even had a compressor shaft snap because the tx was blocked.

as long as it has gas, and the compressor clutches engage it will be a tx related problem. bout an hours work if you havent done it, and about half to vac and regas.

look for someone that will quote for free, there are a couple in slacks creek in brisbane.

[proRB88]

hey guys,

I got gas 3 bars, the pump does switch on, when you press the a/c button, but the problem is as soon as the car start to heat up, or gets rev'd it switches off.

Some1 told me that it could be that house that plugs into the dash has fallen off but when i checked it, it was on. Could it be the actual plug that goes into the resister or whatever it is, is faulty.

I'll start checking around for people that don't look shoncky, and are willing to do my tx valve. where is it located so at least i can point them in the right direction.

Vlad

[t_revz]

most dont talk bar in a/c. but if its 45psi when car isnt running then prob has a leak and could be cutting out when compressor goes faster as it goes into a vacumn. if its 45 psi while running then not a lack of gas and prob tx.

[fib]

I had same problem as yours, with aircon turning off when engine was warm. I had two issues though, one was the thermister it was freezing the pipes at times; the other was tx valve which was replaced and things work fine now.

[Sarumatix]

I've got an A/C system that appears to be working but when the AC signal from the ECU is sent.. nothing happens. Could this be TX related?

[jrm]

hey guys,

I got gas 3 bars, the pump does switch on, when you press the a/c button, but the problem is as soon as the car start to heat up, or gets rev'd it switches off.

Some1 told me that it could be that house that plugs into the dash has fallen off but when i checked it, it was on. Could it be the actual plug that goes into the resister or whatever it is, is faulty.

I'll start checking around for people that don't look shoncky, and are willing to do my tx valve. where is it located so at least i can point them in the right direction.

Vlad

The car will switch the aircon off if you rev it out - that's normal.]

Additionally, in really hot weather (think 35+C), your front aircon fan should kick in and ensure there's some airflow to the condenser - it will still not be as cool as it could be - but will cool down as soon as you get going and gets airflow. Lots of people remove this fan to fit larger intercoolers - it also can become unplugged very easily - I'd definitely check here too.

[proRB88]

The car will switch the aircon off if you rev it out - that's normal.]

Additionally, in really hot weather (think 35+C), your front aircon fan should kick in and ensure there's some airflow to the condenser - it will still not be as cool as it could be - but will cool down as soon as you get going and gets airflow. Lots of people remove this fan to fit larger intercoolers - it also can become unplugged very easily - I'd definitely check here too.

Hey JRM,

I did find out i need a new clutch fan. it works but not to its full extent, the guy who checked my air/con, plugged his Laptop into my car and said that my car doesn't seem to overheat, everything is pretty good he said to change the TX vlave and clutch fan then go from there. NOw my only drama is i need to find a good air/con mechanic who is will to do the TX valve and isn't going to charge me an arm and a leg.

ill keep you all posted as too how everything works out, cost wise as well, just so if any1 else ever runs into this problem at least they know what they are looking at.

Vlad

[BNDAIR]

I know I'm digging  up an old thread, but has anyone removed/replaced their TX Valve on an R34?

I have read that you have to remove the whole dash? Is this true? Or can you just get to it from behind the glovebox?

I have removed my glovebox but can only see the the cabin filters.

Any advice on getting TX valve out?

[t_revz]

Out of curiosity why do you want to change it? What symptoms?

[BNDAIR]

My car has not had any gas in the A/C system since I brought it. I know my condenser and receiver/drier were cactus, so I replaced them. My understanding is that the TX valve can seize when it has been sitting around without gas (and with age), so I decided to replace it as a precaution before I have the system gassed up.

I got it all out last night. Took about 40mins and a trained monkey could do it.

In case anyone is interested, here is how you remove the A/C evaporator and TX valve on an R34:

1. have the gas removed and do not use the A/C system with out gas
2. in engine bay, remove the A/C metal pipes which go to the firewall behind the turbo (one 10mm and one 12mm)
3. remove the passenger kick panel and glove box
4. behind the glove box is the unit with the fan blower, cabin filters and A/C evaporator
5. unplug the electrical plugs shown in green on the attached pic
6. remove the 10mm nuts shown in red on the pic. The top one is hidden and a b!tch to get to, but a stubby ratchet and bit of mucking around will get it out
7. ease it the whole unit down and out

Now you can remove the screws and clips to pull apart the plastic cover and get to the A/C evaporator.

The TX (Thermal Expansion) valve is the metal part on the front of the evaporator which connects to the pipes in the engine bay.

Hope this helps someone out there.