Timing Belt and Air-Con

[fitshase]

I've just had the timing belt changed on my 03 Megane 1.6 16v as one of the pulleys had disintegrated and caused the belt to slip therefore bending 3 valves.

Anyway, had it all done and picked the car up today (very hot day!). However, the air-con is not coming through as cold as it used to. In fact it is not coming through cold at all.

Could this be connected with the timing belt issue or have I been unlucky enough to have something else go wrong?!

[markren2004]

they will have had to remove the AUX belt that drives the aircon compressor, but unlikely anything to do with this, if the aircon is working ok, and it continues to work, but just not very cool, probably just a hotter day, so you notice it more ?
you can get a Aircon service from the likes of kwikfit, which will also test the system for leaks (although if you had a leak it would stop working altogether), top up the gas and the compressor oil for £45

[fitshase]

The air-con used to be very cold before it went in for the timing belt. I've tried running it without the air-con on and then switching it on and I can't hear the compressor kicking in so I think the air-con is not functioning.

What is the AUX belt? Is it something they could have missed when putting the engine back together?

[markren2004]

i thin the belt drives other things like teh alternator, so can't have forgot to refit it.
They may have knocked some pipework and caused a leak (the pipework / compressor is in the same area where they would be working to change cambelt) , which would stop the compressor from engaging.
you'll need to take it up with the garage that did the work.

[fitshase]

Cheers for your help. I've contacted the garage and took it in for a quick look. The couldn't find anything obvious but they have said to take it back in on Monday as they have an auto-electrician coming in who will check the electrical side of it.

[terry_mccann]

can you please keep us informed about the happenings?

I had my timing belt changed and have nearly the same problem....since then the AC does no longer kick off when it is very hot....works ok if temps are a bit lower....

[fitshase]

can you please keep us informed about the happenings?

I had my timing belt changed and have nearly the same problem....since then the AC does no longer kick off when it is very hot....works ok if temps are a bit lower....

Will do. My air-con doesn't start at all (even with lower temperatures - just tried it today). Hopefully it's something simple.

[AlexB]

See the algorithm of aircon control is in the manual (Links section). It is too complex to describe in a few words.

can you please keep us informed about the happenings?

I had my timing belt changed and have nearly the same problem....since then the AC does no longer kick off when it is very hot....works ok if temps are a bit lower....

[terry_mccann]

will check there, cheers.....

what section under links?

[AlexB]

the second link here:
viewtopic.php?f=6&t=5167

In particular, p.347 in this file
https://meganedoksi.uw.hu/MEGANE_II/MR364MEGANE1.PDF

[terry_mccann]

great, thanks a lot, mate.....

[terry_mccann]

ah, ok, know these documents. if anybody can speak better german than french I have the complete set in german....just PM me for a download link.....but very interesting, this information on the connection between injection and aircondition systems....havent read that....

[cactusbob]

It's pretty simple, you turn the aircon on and about 10 seconds later the compressor clutch engages (which you should be able to hear if you listen carefully). If it doesnt then it could well be the refrigerant pressure sensor - when low it prevents the compressor engaging. As others have said it is unlikely they have forgotten the auxilliary belt, unless of course they have put an Aux belt on and not hooked the compressor up to it (like in a non-aircon car).

Obviously check all the fuses you can get access to as well...

[terry_mccann]

@bob

dont think it is a pressue issue at all....it was newly filled up last week and when it runs it cools very strongly and normal.
I guess it is more a case of the magnetic coupling not connecting the compressor mechanically or some electric fault with a connection of some kind.....at first I thought that it was only on very high temeperatures but now today I also had the effect on a clouded day....

[cactusbob]

Yes but if the pressure sensor is reporting low gas (whether thats true or not) it will no engage compressor. Its a common fault. You can get to it through the wheel arch I think. Get the wheel off and the arch liner and have a look. It could be an unplugged connector perhaps