Couple more questions - Exhaust and Air Con

[adentonmiller]

Sorry, but this will be a bit long and rambling.....

So I successfully got my son's Polo (2005 1.2 9N) through the MOT last month after fixing various bits and pieces.

On the first MOT test, it failed emissions due to a leak in the centre section of the exhaust. I took it to a local garage and they fixed it for £20. It then passed the emissions and the MOT.

Now he's back from Uni and has been driving it around for a a weeks and the exhaust has started blowing yesterday.

Anyway - I also bought him the Groupon air con recharge deal and so he went over to ATS this morning to get that done. I told him to have them look at the exhaust while he was there and see what the problem was and get a price to fix it.

So he comes back and tells me (he's not the best listener or communicator) the following;

On the exhaust, "it's basically all f****d apart from the cat. The front section is the worst. Something to do with 2 plates which might be missing, but the cat is good. It's been "buttered all over". It will cost £400 to replace the exhaust system"

(My thoughts - isn't the cat part of the front exhaust section? I see you can buy a full 3 piece exhaust system online for £60. I have asked him to take it to the local garage that fixed it before so they can have a look and determine if it was their "fix" that is causing the problem now. I have also shown him how the exhaust comes in three parts so he can have a more intelligent conversation with them about what the actual problem is....

On the air con: "They filled the canister with nitrogen, but said it still won't blow cold air into the car because there is a problem with the compressor. But it could just be a switch, but we don't deal with compressors here so can't help you"

(My thoughts - what switch could this be? Pressure sensor perhaps? I'll have to get the manual out and read up on the AC system - any thoughts?)

SO - as I said long and rambling - but if anyone with knowledge of these cars exhaust and air con systems could throw their tuppence worth in it would be appreciated!

[RUM4MO]

Exhaust, maybe currently all in one piece if still the factory fitted one, the manucat is the cat and exhaust manifold in one assembly, then you have a short bend then a flexi section, after that the middle box or resonator, section of exhaust then a rear box. The middle box might even be a second cat, I've forgotten, but the flexi section which is welded to the first section does tend to fail.

AC, sometimes, the control wiring fails where it passes from the gearbox engine joint towards the compressor, that would stop the AC chilling, I'm guessing that they recovered the fridge gas charge, and vac'd it out to dry it and check for leaks, then recharged it with R134A and not Nitrogen, Nitrogen would only ever be used to pressure check the system if they had found it could not achieve and hold a vacuum.

[adentonmiller]

Thanks for the tips - will have a look and see tomorrow.,

I wish I had easy access to a proper hydraulic lift rather than a couple of axle stands and a trolley jack.

[RUM4MO]

So do most of us DIYers!

I remember when my wife's September 2002 Polo 1.4 16V at just over 5 years old, needed to get its exhaust sorted, the flexi section had started to pull away from the exhaust - my only option at that time was a VW sourced exhaust section that included that flexi section and the second cat, so that meant over £300! No aftermarket parts available at that point in time! That was enough for me to search out a proper exhaust fabricator and get them to remove the short flexi and fit an identical flexi which includes welding it into the exhaust - they messed up and the exhaust touched/hit the under side of the car under certain conditions and resonated badly, now being an exhaust specialist and one that regularly got cars left with them to design and build new SS exhausts, meant that they denied everything and questioned me questioning them!!! Not a good outcome, so now that the original flexi section had been cut out, I needed to get a fellow forum member, on the Skoda Fabia forum, to measure up their original flexi on a car with that same engine, with that info I could see that my specialist had sourced and fitted a flexi that was too short and too big a diameter, so I sourced one the correct dimensions and got them to replace it, problem solved, so you need to watch out for specialists as they can and do get it wrong at times, and some don't care about that!