Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: grifter on 24 May 2018, 22:22:37

Title: Air con low pressure pipe hot
Post by: grifter on 24 May 2018, 22:22:37
Hi, i've got a good pressure in my AC now and compressor kicked in but 1) no cool air and 2) the low pressure pipe is quite warm to touch, the HP pipe is burning, I know the HP gets hot but I don't think it should be burning hot and the LP should be cold. Any thoughts?

Title: Re: Air con low pressure pipe hot
Post by: DrAndyB on 27 May 2018, 18:30:42
Take it to be re-gassed.  Note how much comes out, as I think from memory there is should a 950g of R134a !!

Worth getting a new HP valve and LP core and get them to pop them on before filling  :y

At least you will know what is in there is what it should be.

Also, is the compressor spinning ? Should be easy to eyeball it  ;)
Title: Re: Air con low pressure pipe hot
Post by: biggriffin on 27 May 2018, 19:33:15
Take it to be re-gassed.  Note how much comes out, as I think from memory there is should a 950g of R134a !!

Worth getting a new HP valve and LP core and get them to pop them on before filling  :y

At least you will know what is in there is what it should be.

Also, is the compressor spinning ? Should be easy to eyeball it  ;)


Compressor only spins if enough gas,is present, if it detects either to much or to little, won't engage.
Title: Re: Air con low pressure pipe hot
Post by: DrAndyB on 27 May 2018, 20:15:05
Take it to be re-gassed.  Note how much comes out, as I think from memory there is should a 950g of R134a !!

Worth getting a new HP valve and LP core and get them to pop them on before filling  :y

At least you will know what is in there is what it should be.

Also, is the compressor spinning ? Should be easy to eyeball it  ;)


Compressor only spins if enough gas,is present, if it detects either to much or to little, won't engage.
:y
Title: Re: Air con low pressure pipe hot
Post by: grifter on 27 May 2018, 22:01:38
Take it to be re-gassed.  Note how much comes out, as I think from memory there is should a 950g of R134a !!

Worth getting a new HP valve and LP core and get them to pop them on before filling  :y

At least you will know what is in there is what it should be.

Also, is the compressor spinning ? Should be easy to eyeball it  ;)

Yep was spinning. What do you mean LP core?
Title: Re: Air con low pressure pipe hot
Post by: biggriffin on 27 May 2018, 22:18:24
Take it to be re-gassed.  Note how much comes out, as I think from memory there is should a 950g of R134a !!

Worth getting a new HP valve and LP core and get them to pop them on before filling  :y

At least you will know what is in there is what it should be.

Also, is the compressor spinning ? Should be easy to eyeball it  ;)

Yep was spinning. What do you mean LP core?

Looking into bonnet from front of car, LP valve is the one near bulkhead,(std tyre core),, HP is just the one at front above fan. (GMpart)
Title: Re: Air con low pressure pipe hot
Post by: abokayed on 27 May 2018, 23:26:45
Hey Sir! , from what you have mentioned i can tell that you have a problem in the AC System , not sure where it comes from but i tell you from what i know , because i had an experience with this matter before , so the thing is as follows , the HP Line should be hot , i mean like real hot that is a normal thing , but the low pressure pipe should be significantly COLD to touch , when everything works as it should be make sure of the following as a checklist

- make sure the condenser fins are not clogged with Dust , particles and insects , make sure to clean it
- Make sure that the condenser fan kicks in at the right speed when you turn the AC system usually at the high speed but it could run in low speed
  depending on the weather and traffic ....etc
- the amount of R-134 (Refrigerant Gas) is the right amount as mentioned from the car manufacturer which i think is (950 gram)
- there is no water moisture in the system - this can be solved by taking it to AC specialist to suck all the moisture out and vacuuming the system and refilling it with the right amount of R-134 (Refrigerant Gas)
- the compressor is not working efficiently (could be a bad compressor) - it is recommended to change the Receiver Dryer when you change the compressor
- Faulty Expansion Valve
- Clogged condenser or evaporator
Title: Re: Air con low pressure pipe hot
Post by: grifter on 28 May 2018, 07:30:37
Hey Sir! , from what you have mentioned i can tell that you have a problem in the AC System , not sure where it comes from but i tell you from what i know , because i had an experience with this matter before , so the thing is as follows , the HP Line should be hot , i mean like real hot that is a normal thing , but the low pressure pipe should be significantly COLD to touch , when everything works as it should be make sure of the following as a checklist

- make sure the condenser fins are not clogged with Dust , particles and insects , make sure to clean it
- Make sure that the condenser fan kicks in at the right speed when you turn the AC system usually at the high speed but it could run in low speed
  depending on the weather and traffic ....etc
- the amount of R-134 (Refrigerant Gas) is the right amount as mentioned from the car manufacturer which i think is (950 gram)
- there is no water moisture in the system - this can be solved by taking it to AC specialist to suck all the moisture out and vacuuming the system and refilling it with the right amount of R-134 (Refrigerant Gas)
- the compressor is not working efficiently (could be a bad compressor) - it is recommended to change the Receiver Dryer when you change the compressor
- Faulty Expansion Valve
- Clogged condenser or evaporator

Thanks i will get these checked, i know from experience hp pipe should be warm, think it was too hot almost to touch, which led me to believe one of the things or a combination were at fault, a blockage, poor circulation etc.
Title: Re: Air con low pressure pipe hot
Post by: Andy A on 28 May 2018, 09:27:40
Take it to be re-gassed.  Note how much comes out, as I think from memory there is should a 950g of R134a !!

Worth getting a new HP valve and LP core and get them to pop them on before filling  :y

At least you will know what is in there is what it should be.

Also, is the compressor spinning ? Should be easy to eyeball it  ;)

Your memory is correct. The label on mine says 950g.  :y
Title: Re: Air con low pressure pipe hot
Post by: Andy A on 28 May 2018, 10:27:36
A couple photos and a part number for the HP valve.  :y This is from my 2.2 so your layout might be slightly different but the HP valve is identical.

(https://s6.postimg.cc/9m3miy85t/P1040177.jpg)

Low pressure Valve (LP). Standard AC valve core or tyre valve core.
(https://s6.postimg.cc/qzdwxtiwh/P1040191.jpg)

High Pressure valve (HP). P/N 13277003
(https://s6.postimg.cc/rowpa6bq9/P1040194.jpg)



Title: Re: Air con low pressure pipe hot
Post by: abokayed on 28 May 2018, 12:38:19
Hey Sir! , from what you have mentioned i can tell that you have a problem in the AC System , not sure where it comes from but i tell you from what i know , because i had an experience with this matter before , so the thing is as follows , the HP Line should be hot , i mean like real hot that is a normal thing , but the low pressure pipe should be significantly COLD to touch , when everything works as it should be make sure of the following as a checklist

- make sure the condenser fins are not clogged with Dust , particles and insects , make sure to clean it
- Make sure that the condenser fan kicks in at the right speed when you turn the AC system usually at the high speed but it could run in low speed
  depending on the weather and traffic ....etc
- the amount of R-134 (Refrigerant Gas) is the right amount as mentioned from the car manufacturer which i think is (950 gram)
- there is no water moisture in the system - this can be solved by taking it to AC specialist to suck all the moisture out and vacuuming the system and refilling it with the right amount of R-134 (Refrigerant Gas)
- the compressor is not working efficiently (could be a bad compressor) - it is recommended to change the Receiver Dryer when you change the compressor
- Faulty Expansion Valve
- Clogged condenser or evaporator

Thanks i will get these checked, i know from experience hp pipe should be warm, think it was too hot almost to touch, which led me to believe one of the things or a combination were at fault, a blockage, poor circulation etc.

You are more than Welcome   :) , about the temperature of the HP line i know that it gets too hot and it is normal that way, i noticed this with 3 different cars , that you cant touch it from its heat. so from my side i think that is a normal thing , i could be wrong but i said this based on my experience with it from different cars

Thanks!
Title: Re: Air con low pressure pipe hot
Post by: grifter on 28 May 2018, 13:45:43
Hey Sir! , from what you have mentioned i can tell that you have a problem in the AC System , not sure where it comes from but i tell you from what i know , because i had an experience with this matter before , so the thing is as follows , the HP Line should be hot , i mean like real hot that is a normal thing , but the low pressure pipe should be significantly COLD to touch , when everything works as it should be make sure of the following as a checklist

- make sure the condenser fins are not clogged with Dust , particles and insects , make sure to clean it
- Make sure that the condenser fan kicks in at the right speed when you turn the AC system usually at the high speed but it could run in low speed
  depending on the weather and traffic ....etc
- the amount of R-134 (Refrigerant Gas) is the right amount as mentioned from the car manufacturer which i think is (950 gram)
- there is no water moisture in the system - this can be solved by taking it to AC specialist to suck all the moisture out and vacuuming the system and refilling it with the right amount of R-134 (Refrigerant Gas)
- the compressor is not working efficiently (could be a bad compressor) - it is recommended to change the Receiver Dryer when you change the compressor
- Faulty Expansion Valve
- Clogged condenser or evaporator

Thanks i will get these checked, i know from experience hp pipe should be warm, think it was too hot almost to touch, which led me to believe one of the things or a combination were at fault, a blockage, poor circulation etc.

You are more than Welcome   :) , about the temperature of the HP line i know that it gets too hot and it is normal that way, i noticed this with 3 different cars , that you cant touch it from its heat. so from my side i think that is a normal thing , i could be wrong but i said this based on my experience with it from different cars

Thanks!

I do know the lp pipe should be cold and gather condensation, and it definitely wasn't, lukewarm to touch.
Title: Re: Air con low pressure pipe hot
Post by: abokayed on 28 May 2018, 14:35:23
Hey Sir! , from what you have mentioned i can tell that you have a problem in the AC System , not sure where it comes from but i tell you from what i know , because i had an experience with this matter before , so the thing is as follows , the HP Line should be hot , i mean like real hot that is a normal thing , but the low pressure pipe should be significantly COLD to touch , when everything works as it should be make sure of the following as a checklist

- make sure the condenser fins are not clogged with Dust , particles and insects , make sure to clean it
- Make sure that the condenser fan kicks in at the right speed when you turn the AC system usually at the high speed but it could run in low speed
  depending on the weather and traffic ....etc
- the amount of R-134 (Refrigerant Gas) is the right amount as mentioned from the car manufacturer which i think is (950 gram)
- there is no water moisture in the system - this can be solved by taking it to AC specialist to suck all the moisture out and vacuuming the system and refilling it with the right amount of R-134 (Refrigerant Gas)
- the compressor is not working efficiently (could be a bad compressor) - it is recommended to change the Receiver Dryer when you change the compressor
- Faulty Expansion Valve
- Clogged condenser or evaporator

Thanks i will get these checked, i know from experience hp pipe should be warm, think it was too hot almost to touch, which led me to believe one of the things or a combination were at fault, a blockage, poor circulation etc.

You are more than Welcome   :) , about the temperature of the HP line i know that it gets too hot and it is normal that way, i noticed this with 3 different cars , that you cant touch it from its heat. so from my side i think that is a normal thing , i could be wrong but i said this based on my experience with it from different cars

Thanks!

I do know the lp pipe should be cold and gather condensation, and it definitely wasn't, lukewarm to touch.

Yup That is Correct , that is the biggest indicator that ur AC System is not working properly
Title: Re: Air con low pressure pipe hot
Post by: grifter on 03 July 2018, 13:48:14
Is it easy enough to access the condenser,  do I need to remove the fans only to get in to check it's clean?
Title: Re: Air con low pressure pipe hot
Post by: Doctor Gollum on 03 July 2018, 13:54:00
You can, but you'll need to remove the radiator and condenser in order to remove the fans...

 ;D
Title: Re: Air con low pressure pipe hot
Post by: grifter on 03 July 2018, 18:15:41
You can, but you'll need to remove the radiator and condenser in order to remove the fans...

 ;D

Not just the 2 fans behind grill, they have to come out backways towards engine? There is one fan in front of rad, 2 at grill side. I take it air con fans don't come out front ways?
Title: Re: Air con low pressure pipe hot
Post by: Doctor Gollum on 03 July 2018, 22:01:17
Like I said ;)
Title: Re: Air con low pressure pipe hot
Post by: grifter on 04 July 2018, 07:46:05
Had a look through rads with torch and can clearly see right through fins. Not really convinced they are blocked bad enough to cause it not too cool. While my pressure gauge is showing into the green, compressor kicks in and fans running when an on, any other thoughts what it could be. I measured temp of compressor and pipes with infra red temp reader, getting 40 oC on LP pipes, 70  odd on comp and associated pipes. Condenser was about 38 on passenger side, 32 on driver side
Title: Re: Air con low pressure pipe hot
Post by: Doctor Gollum on 04 July 2018, 11:59:49
Get it regassed professionally  ;)
Title: Re: Air con low pressure pipe hot
Post by: LC0112G on 04 July 2018, 16:30:36
The coldest part of the A/C system is the expansion/oriface valve. If the system is left without gas in it for any length of time then it can fill with air. Air contains water vapour.

If any water/water vapour isn't properly purged (vacuumed) from the system before being refilled, then the water/water vapour can freeze in the expansion valve and effectively bung the whole system up. This causes the pump to work hard pressurising the coolant into the HP side, but if there is no flow of gas around the system, then all that happens is the gas gets hotter and hotter. The pump has an overpressure cut out, so it may well deactivate itself if this happens, till the ice in the expansion valve melts again. I think the expansion valve is in the cabin behind the dash on an Omega B?

There is a dryer in the system too - it's part of the A/C rad on an Omega - that bottle shaped canister on the front nearside of it. This contains a sort of silica gel, and it's job is to try and capture any moisture in the system. This should not be left exposed to atmosphere for too long before re-gassing because it will capture moisture from the environment. I assume your new rad came fitted with a new dryer? Mine did.

The pipework down the passenger side of the engine on my car (3.0 24V RHD saloon) is ice cold within 10 seconds of starting the engine - too cold to hold onto for very long.

ETA : Just remembered - I've got a digital thermocouple widget in the boot :y. The LP pipework (where the LP valve is) measured +5 DegC. The HP pipework (out of the compressor near the HP valve) measures 55+ degC.  Ambient here is around 20 DegC today.
Title: Re: Air con low pressure pipe hot
Post by: Kevin Wood on 04 July 2018, 16:54:12
In addition, the expansion valve in an Omega is temperature controlled to prevent the evaporator from icing up and to provide variable cooling to suit the ambient temperature. They have been known to fail.

But: Until you know that the system is dry, gas tight and has the correct mass of refrigerant in it, all bets are off. The only way to achieve this is to get it vacuumed out and refilled.
Title: Re: Air con low pressure pipe hot
Post by: grifter on 05 July 2018, 07:55:31
Found a place in Glasgow who does diagnostics, only 25 bucks for a diagnosis test, most garages round here are saying they can just top gas up.
Title: Re: Air con low pressure pipe hot
Post by: Nick W on 05 July 2018, 10:53:14
Found a place in Glasgow who does diagnostics, only 25 bucks for a diagnosis test, most garages round here are saying they can just top gas up.


They're not going to diagnose anything until the system is gassed and any obvious leaks sorted
Title: Re: Air con low pressure pipe hot
Post by: grifter on 05 July 2018, 11:20:20
Found a place in Glasgow who does diagnostics, only 25 bucks for a diagnosis test, most garages round here are saying they can just top gas up.


They're not going to diagnose anything until the system is gassed and any obvious leaks sorted

That's what I'll be getting them to do. Check for leaks first, vac test.

Also found out what the little button is on centre too of dash, a sun sensor, something to do with climate control as well.