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[danzigfan]

Thanks

[danzigfan]

I replaced the ac compressor, toom it to regas and more problems showed up...It holds vacuum, ac clutch works as it should, but no cold air from vents....The ac line was freezing cold at the first start, but than remain warm/hot after starting ac again. Anyone had this issue?

[biggriffin]

Are fans switching on when air-con is on.   There's an expansion valve up behind the glove box,, very rare they fail.

[danzigfan]

Yes, fans are switching on

[LC0112G]

Can you control the internal vent temperature by changing the temperature dials with the A/C turned off? I mean, can you get both hot air and cold air? if not it could be that the flaps/actuators in the heater box are jammed.

It's also worth measuring the temperature of the two A/C pipes that go into and out of the engine bay bulkhead. One of them should be cold, and the other warm/hot.

[danzigfan]

A/C pipe was cold only on first start up...then luke warm and later hot. No worky

[LC0112G]

A/C pipe was cold only on first start up...then luke warm and later hot. No worky

This may be illegal to do yourself in your country unless you have the correct ticks in various nonsense training boxes, but....

Your symptoms sound like lack of gas to me. You need someone to put some pressure gauges on it. https://www.ebay.co.uk/itm/403116218375

These allow you to measure the gas pressures in the pipes either side of the compressor. With the engine not running, both pressures should be the same - typically 4 or 5 bar IIRC. With the engine running (well compressor running really) then before the compressor the pressure should be low-ish (2-5 bar IIRC), and the pipe will be cold. After the compressor the pressure will be high (20+ bar IIRC), and the pipe will be warm/hot.

If the system is blocked, then you'll end up with very high pressure in the HP side, and less than atmospheric in the LP side. If the system is low on gas, then the compressor can't generate enough differential across the expansion valve to give the required cooling. If the system is empty of gas, then the LP cutoff switches will stop the compressor clutch from engaging.

[danzigfan]

Thanks for the advice, system isn't blocked for sure, because the pressure isn't high enough, when the compressor is running. It should be around 20 yes, but it doesn't reach that pressure at all. The system took 700g of gas both times, because I went to two diferrent ac refill places

[LC0112G]

Thanks for the advice, system isn't blocked for sure, because the pressure isn't high enough, when the compressor is running. It should be around 20 yes, but it doesn't reach that pressure at all. The system took 700g of gas both times, because I went to two diferrent ac refill places

It may have taken 700g of gas when filled, but how sure are you that there still 700g in there now? Personally I don't really like filling the A/C with gas by weight/mass. Much better to do it by running pressures IMO.

Measuring BOTH the LP and HP sides should tell you what is going on. The LP side needs to stay above (about) 2 bar when the system is running, otherwise the LP cutout turns the compressor off to avoid damaging it. The HP side should reach 15-20 bar. There is a HP cutoff there too but I'm not sure what that is on an Omega - probably around 20-25 Bar.

If there isn't enough gas in the system, then you can get the LP/HP running at (say) 2Bar/10bar, which is enough to keep the cutout switches happy, but the HP side isn't high enough to give good cooling. Or if your new compressor is a load of junk similar things happen.

[amba]

Just had my A/C recharged a few weeks ago after last being done approx 3 years ago.

I always remember A/C system when fully vac down to hols a charge of 950 grams so I would say at 700grams your is light and whist enough to engage the compressor not enough to give correct cooling.

[Raeturbo]

I agree, mine took over 950. I think they actually hold 1kg (of course can vary on temp blah blah etc..,,,,

[danzigfan]

Did you ensist on filling the system with 900 grams?
Because they just find the car make and model on the ac machine and it says 700g on display...so the machine does all the work, no brain involved

[Raeturbo]

The machines normally work it out as far as I know and will fill them up.??

[danzigfan]

Well, I'm going to try this on my other Omega...hopefully the mechanic will be willing to fill the system with 200 grams more

[Raeturbo]

Just ask him to fully empty and fully fill. Although I think the automatic AC machines are programmed to fill to maximum anyway