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MG MGF Technical - Air conditioner problems

Hello everyone,

I am new to this BBS so I apologize if this issue has been dealt with already.

I own a '97 VVC and I have experienced some problems with the air conditioning unit. Right from the start the A/C has been weird:

1. Their is a "click" noise coming from behind the dashboard on the right hand side which is reflected in a little rise in rpm when idling (up to 1400-1500, then immediately but slowly going back down to normal). I know that the compressor is supposed to on and off according to changes in conditions (heat, rpm etc) but here it happens when the cars is just sitting there idling...

When the clicking happens to coincide with me changing gear while driving, the revs get hung up for a moment, like if I hadn't eased off the throtle properly.

This makes progress in trafic very jerky and annoying, leading to me prefering to sweat than to have it on in town.

2. My other A/C problem is that sometimes when idling (at a red light or something) there is a terrible rattle somewhere behind the pedal box, which disappears when reving the engine a bit. This only happens with the A/C on and the rattling seems to coincide with the click mentioned above, but I'm not sure. My dealer says he has tightened the tubes and stuff going under the floor between A/C unit and engine, but the rattling is still there.

I would appreciate any help or advice!

Per
Per Lagergren

I do not know the aircon as fitted in the *F* but to me it sounds as though there is a faulty relay and/or faulty ECU.

I would suggest that you get your dealer to check it for you.

Ted
Ted Newman

Just checked the workshop manual and there is indeed a relay behind the dash, mounted on or close to the the evaporator unit (blower/fan unit) the ECU or ECM as Rover call it is in the boot.

A relay unit that is faulty would certainly give you this 'rattle' that you talk about as it constantly clicks in and out. However the fault could be somewhere else and the relay is just trying constantly to signal the compressor or other unit.

I do feel that it needs to be checked by your dealer or an auto aircon specialist.

Ted
Ted Newman

Actually, the rattle and the clicking are two different things: the rattle seems to come from some loose part (or parts...) around the footwell making a terribly loud continuous racket once in a while, whereas the clicking just clicks once (..."click"...) on an irregular basis (say, every 30 seconds to 2 minutes or something...).

I'm puzzled...

Per
Per Lagergren

With all due respects mate, you will remain puzzled unless you get it checked out by someone who knows what they are doing.

I still go for relay 'chatter' and you say it is around the footwell - that is the area where the relay module is mounted.

Ted
Ted Newman

You are probably right, I'll go and see my dealer.

Thanks!

Per
Per Lagergren

Per,

AirCon is standard for F in Taiwan and I got this exactly same problem before. And now the problem solved.

When idleing in jam city street, my F cried like an ox dying in front wheel...It did sound terrible. When I heard it, I did hate my F for that it make me shame in public...:-(

I sent my F to Rover Taiwan workshop and checked many times. The ox crying couldn't alway be heard in garage. So I idled my F in workshop all morning and make the mechanical hear it. It is not a eazy-found problem. Fortunately they heard and found the problem key.
The key is the pressure of refrigerant is set too high. It will make the compressor works too hard to compress the refrigerant, and then it will CRY. The compressor will shake terribly and shout.:-(( You couldn't adjust the refrigerant to proper setting by youself. The adjustment only the garage mechanical can do for you. Because you couldn't check it without the refrigerant preasure gauge.(This gauge has two clocks)

Beware to release the refrigerant too much. If you do so, you will hear another sound like water fall from the air con vent. Don't worry about the setting data, the mechanical knew the data.

Happy driving with aircon,

Don Liang
http://netcity.hinet.net/donliang
Don Liang

Don,

Thanks a lot for your explanation! The comparison with the dying ox is spot on! That is exactly how it sounds (Not that I have ever seen an ox die though...)! I will go to my dealer and tell him to fix it. At the same time, I will ask him to also look at the relay Ted mentioned; I wouldn't be surprised if the compressor having to work too hard is the reasom why the relay clicks on and off constantly.

Maybe this is something that deserves to be included in the FAQ? Who is to be contacted for that?

Per
Per

Waterfall, yes I know that...occurs when turning, sounds like a bucket load of water running around beneath the dash board. This only occurs after the aircon has been on for a while...

Regarding the rattling when idling, my comes from the engine area, on the left hand side (ECU side)....any suggestions....

Jason
Jason

FAO Per,
do you see the FAQ Link on top of this side :)
http://www.mgcars.org.uk/MGF/mgstart.htm

Remove the NOSPAM if you write to Greg
greg.hilton@NOSPAMcompaq.com

Anyway, wait until your problem is solved and the answer is approved.

FAO Jason,
are all parts good fitted around the engine ?
all pipes in their clamps ?
the purge box in its place ?

BTW Have you a brief description for the kind of noise :)
The ox can only be in the aircon <g> :-/

Dieter
NE-WZ 77
Dieter Koennecke

Dieter,

Oh yes... now I see the link (as I said, I am newcomer on this BBS :-) ).

And Yes, I'll wait until it is fixed... I'll keep you posted.

Per
Per

ref adding to the faq, I try and keep up to date with discussions, but email is always welcomed!

Greg
Greg Hilton

Purge box??
Jason

> 'purge box'
Sorry, Jason, (my german englisch ;_)
A name like this stands on the cylindric black box...

I mean the activ coal filter for fuel 'damp' from the fuel tank. Its fitted in such a clamp /.../
at the rear engine panel (to the boot).
Mine was loose and made rattling noises.

Hope you got it :)
shall I post a picture ?

Cheers
Dieter

Dieter

Hi Per,

I am interested to know who your dealer is.

I purchased my MGF at Grand Garage St. Michel back in July 1996. I had some rather bad experiences with them. Ever since, I have my mgf serviced at the MGF-dealership my brother Dirk relies on (Rover Luxembourg - Luxemburg), and I am *very* pleased with those guys (they have an excellent MGF technician working over there and prices are far more less: approx. 950 BF/h instead of approx. 1400 BF/h as they charge in Brussels).

My MGF currently covered over 90,000 kms.

Luc
GHC216
Luc

This is located to the left of the engine bay?? Is it accessable without removing the Cover Plate?

Picture would be useful though...

jason.taylor@chameleontdb.com

Cheers

Jason
Jason

Hi,

Just came back from my dealer who has checked (or so he says) everything with my air conditioner (quantity of refrigerant, pressure in the system, etc ). He said he found nothing wrong with it and wanted me to come back whenever that "dying ox" sound reappears (yeah right... like it's going to happen again just when I drive past my dealer...). Oh well... at least he didn't charge me anything, but the mystery remains... and the haunting will surely return next summer!

Per
Per

Per,

>
I sent my F to Rover Taiwan workshop and checked many times. The ox crying couldn't alway be heard in garage. So I idled my F in workshop all morning and make the mechanical hear it. It is not a eazy-found problem.
<

Remind you. It is not easy to find the problem when in workshop. The ox will not cry when it is tired! :-))
Don Liang

Don,

Thanks for the advice. I will drive with the aircon on for a while now and see if the noise comes back. If it does, I will try do figure out exactly under what conditions, and then try to reproduce these conditions in the workshop.

We'll see...

Per
Per

A general point with Air Con, if not mentioned elsewherer, is that it is very important to run the system at least once a week to keep the system fully functional. Leaving it dormant for periods of weeks or months will often result in problems arising when it is started again. This is applicable to all Air Con systems whatever badge is on the front of the car.

Rog
Roger Parker

This thread was discussed between 28/10/1999 and 11/11/1999

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