Coolant temp sensor & air con ?

[Jonion]

Had the air-con recharged, worked fine at first then noticed that it's gone a bit crappy again already (only 2 wks at most).

Also noticed that the temp gauge is intermittently reading very low .. just slightly above the 60 degree mark.
Then sometimes it will read correctly.

Are the two possibly connected? As in does the temp sender also signal the air con as one of it's temp inputs?

Or any other suggestions .

 

[stoop44rio]

on my 1.8t with climate, the temp with sit mostly at 65ish and rise occassionly to 90 with the c/control switched on. with it switched off the temp sits squarely at 90 and doesnt move.

 

[aragorn]

sounds like either a duff thermostat or a duff Coolant sensor.

It should stay at 90c all the time. Wether its related, i'm not sure.

 

[Jonion]

Well I might jus treplace the temp sensor anyway unless I can fidn the data for testing it.

I got a new thermostat for it.... and have just see nthat you are meant to remove the bumper and half the front of the car to replace it!
Is that right or is there an easier way?

I'm not used to having to work on cars built so inconsiderately to the mechanic!

 

[aragorn]

if its a 1.8T you can do it from underneath pretty easily, without removing anything other than the undertray.

Perhaps your AC system has a leak?

 

[Jonion]

I'm going to look into the possibilty of a leak. Kwik-fit said they checked it prior to recharging though.
Might go in to my local one and get them to re-check it.

No it's the 2.8 V6.
So looks like I may as well do the timing belt, water pump etc while I'm doing it.
What a ridiculous amount of work to replace a thermostat though.

 

[AndyMac]

Replace the temp sender first, as it's cheap and an easy 10 minute job, chances are that's the culprit. Buy a genuine Audi one not ebay junk.
Kwik fit generate more business for A/C specialists than anyone else, take it somewhere that know what they're doing!

 

[Jonion]

I got the timing belt and service done.
Changed thermostat and coolant temp sensor at the same time.
This had no effect on the air con which has got worse over time.

Had it checked and re-gassed today at my local Kwik-Fit.
So once again it is working correctly .. but for how long?
It did not detect any leaks but there was almost no pressure in the system.
So what's the possibility they filled it up to the wrong car spec the first time? There are 3 options and the other two have less gas than mine. So if they under-filled the system would that have caused it to get worse?

If there is a problem and it again gets worse is there a likely problem to look for ?

 

[AndyMac]

STOP GOING TO KWIK FIT! Did you not read the post above?
Take it to a proper A/C specialist, they will drain the system and regas to the correct level. KW just push more gas in which will damage the system - they are a total joke!

 

[Jonion]

YES I CAN READ thanks.
But as Kwik-Fit will do it for free and I happen to know the guy doing it, as well as actually being there while he operates the equipment, I don't see the point in paying someone else to do it until that becomes absolutely necessary. Particularly as this was actually a very good garage that was recently taken over by the KF franchise.
They do not just put more gas in it is drained, flushed, checked and re-gassed/oiled to the proper spec if done by a competent.
I'm not in the habit of tarring everyone with the same brush, not all KF empolyees are bad at their job, like not all main dealers are robbing useless gits either. And some specialists don't live up to that tag.


So can anyone actually answer the questions I posed ?
Cheers.

 

[AndyMac]

Think you've answered all your own questions there. You ask for advice, ignore it then get arsey when reminded that the reason you still have a problem is that you keep making the same mistake. Anyone working at KF that is any good is not going to be working at KF, it really is that simple and dealers are all robbing gits, not all useless granted, but charging £100+ per hour, what would you call it?

 

[staggspeed]

If you had gone to a specialist in the 1st place like andymac has said you would not be having to ask this question because a specialist would have found any fault,leave kwikfit to fitting tyres and exhausts.

I got the timing belt and service done.
Changed thermostat and coolant temp sensor at the same time.
This had no effect on the air con which has got worse over time.

Had it checked and re-gassed today at my local Kwik-Fit.
So once again it is working correctly .. but for how long?
It did not detect any leaks but there was almost no pressure in the system.
So what's the possibility they filled it up to the wrong car spec the first time? There are 3 options and the other two have less gas than mine. So if they under-filled the system would that have caused it to get worse?

If there is a problem and it again gets worse is there a likely problem to look for ?

 

[Jonion]

Well I never asked for the patronising manner nor advice on where to take it.. I asked particular questions about this system that no-one has bothered answering in their rush to slag off KF and their employees..

I never ignored anything, it wasn't relevant.. and get arsey on an internet forum .. yeah that'll be the day..

Odd that KF use the same equipment as most aircon specialists though... lol
I'll just wait until I'm fit to go back to work and od it myself then...


For anyone else that fancies replying to the actual questions be my guest ...


So if they under-filled the system would that have caused it to get worse?

If there is a problem and it again gets worse is there a likely problem to look for ?

 

[AndyMac]

That's what we're trying to convey here. KF will recharge the system, that's all they can do. If the system is working perfectly then you should be alright as long as they have done it properly, however if there is a leak then they do not have the expertise to fix it so you have to take it somewhere else anyway. You say they checked for leaks before regassing? How did they do this exactly? To check for leaks you have to regas the system first with a dye in the gas so you can then see where it is leaking. There is no other way. A proper A/C service is around £80, but if there is a leak then it starts to get expensive as the components aren't cheap and are all located in very inaccessible places. I can only speak from experience and my 2.8Q had very similar issues, I took it to Audi initially (big mistake) then to KF (bigger mistake) before finally going to a specialist who actually diagnosed the real problem and fixed it. Last time I went to KF was after I replaced the front suspension and just needed a wheel alignment (it was Sunday and they were the only place open). They said they weren't allowed to do alignments on Audi's! These are people who "specialise" in wheels & tyres - unbelievable.

 

[Jonion]

Thanks for that Andy.
More like it

They checked it by pressurising the system and then giving it time to then checking system pressure again. they did use dye.
No leaks were detected, I know my way around cars anyway , just don't deal with Aircon so that's why I'd rather ask those that may have experience of it rather than pretend I know it all.
That's not to say there definitely isn't a leak .. the gas had to go somewhere unless they didn't fully recharge it the first time. There are 3 options on their equipment, two are quite a bit less gas than mine takes.

And don't worry, I'd never ask KF to repair my car ( maybe you thought that was my plan?).. thats' my job, I only expect them to find the fault/leak so I can do it myself.
Then get them to recharge it after the fix if needed.
The problem so far is not being sure if there is a problem.

Today I went out and when I got back the two pipes that go into the bulkhead by the battery were wet.. is this normal and simply condensation? Or is that a possible problem area?

 

[Broken Byzan]

yep normal, one should be noticably cooler than the other too

 

[Jonion]

OK cheers, I'll check that later then.

 

[AndyMac]

A/C is a specialist job, it's only because most cars have it now that everywhere is jumping on the band wagon & offering top-ups and A/C servicing as an easy revenue stream. You said it yourself that you know what you're doing in the engine department, but not anything to do with A/C, so why would a tyre monkey have the necessary skills and experience to diagnose an A/C problem? It's like asking your GP to perform brain surgery. I wouldn't let a high street franchise check my tyre pressures let alone fiddle with the A/C.