Old cars & Emissions ?

avstar

Hi All

My faithful old renault clio (M reg 1995) has failed its MOT.

The main thing is it has failed quite considerable on its gas emissions. The chap who runs the garage (who is a family friend) says he can try to get the emissions to pass but he might not be able to. I was getting the impression that since the laws became so strict that old cars might not ever be able get through the emissions test no matter how much you tweak them. Is this right ? There's no point in trying if this is the case. The car's hardly worth anything (except to me!), but I can't afford to get another one.

What to do ? I don't really understand the whole emissions thing.

Cheers for any info /advice
avstar

Throbbe

I'm struggling to remember the year that catalytic converters became compulsary, but I think yours will have one. To work at full efficiency they need to be hot, so if he didn't take it for a bit of a run first, this might be worth trying. Most testers (in my limited experience) will leave the car idling to warm things up, but it really needs a good thrash to get it nice and hot.

I'd be suprised if your friend didn't know this, so it's probably the basis of his offer to try and get it through. Presumably he wont charge you just for checking emissions before booking a test slot.

avstar

Thanks Throbbe
I got the sheet showing the gas measurements and he took two readings - the first one was out a little bit and then the second reading later was out by a lot !

It was as if the emissions were getting worse the longer the car was on. There's possibly something blowing in the exhaust which the mechanic is going to check out so that might be affecting it. I really hope it will pass cos I need my little car !

mr_accountant

ave you got your sheet of paper witht the readings? this will help.

"cats" came in around 1993, so yours will have one, but it could also be a faulty oxygen sensor, or posiblly a hole in the exhaust.

robnye

my 'M' reg fiesta failed its mot last week, on emissions.......
possible cause was blown gasket along with either catalytic converter or the lambda........ either way without fixing/fitting the mechanic could not gaurantee the car would pass the emissions test

i had the lambda changed 4 years ago and the whole of the exhaust inclduing cat changed 2 years ago..... the cost to repair/re mot was too exhorbitant considering there was no definate gaurantee that it would pass - so i got rid

some one else told me that 1997 was when cats where not installed any more - although i may have miss heard them

avstar

I haven't got the test note with me at the moment as I'm at work - will post it later thanks !

I think there might be a hole in the exhaust somewhere - I've heard a faint blowing noise for a couple of weeks but nothing bad. Also there was mention of the Lamda sensor on the MOT fail sheet but I had no idea what this meant - what is it ? !

moonrakerz

I read the other day that the "emissions" produced by building a new car are far more than would ever be produced if you keep your old banger going for years and years !

anewman

moonrakerz wrote: »

I read the other day that the "emissions" produced by building a new car are far more than would ever be produced if you keep your old banger going for years and years !

Yes, there's a big "I want a new car every year" attitude that everyone seems to have with no regard for anything but the fact they have a new car with a new reg every year to show off to the neighbours.

My Skoda Favorit 94 (cat converter, 1.3i) failed the emissions test but it was just because the centre exhaust was blowing. Repaired exhaust and emissions were all sorted.

The lambda sensor is part of the fuel injection system on your car. I'm no expert but as I understand tt monitors the oxygen content in the engine, changing the petrol flow to get this to the optimal level. If this does not function correctly it will usually lead to fuel being pumped as much as possible to the engine which can lead to emissions failure. A blowing exhaust can also lead to this happening with the lambda sensor as the system isn't sealed and more oxygen gets into it or something, and the system will pump more fuel in to compensate.

From what you say avstar it sounds like your exhaust needs sorting. Don't bother with the Lambda sensor yet unless it fails the re-test as it will cost you about £100. Also if your oil has not been changed for a year, get that and the filter changed before re-test, preferably have the engine flushed using a flushing oil too before having the new oil and filter put in. Also spark plugs and air filter may help slightly if these haven't been changed in a while.

Just before the re-test let the car idle to let the temp rise as high as possible.

vaio

I think emissions (and the rest of the test) test the car against how it was when it was new, so a 2007 audi must squirt mountain fresh air out of the exhaust to pass whereas a 1937 Austin 7 will pass as long as it’s not actually laying a smokescreen.

Lambdas sensors and cats only work when hot so a good hard run is a good idea before a test, unfortunately they don’t last for ever and cats particularly can be expensive.

nickj_2

my nieghbour has just returned from working in denmark , he told me that all new cars are so heavily taxed that people take great care of their old cars which are 20 yrs old

avstar

Thanks for all the advice - I'm going to ask the garage to check out the exhaust as there's the blowing noise (only slight) that might afffect the reading. I had a full service and oil change about 2 months ago so that should all be OK. I've also put some engine flush type stuff in the petrol tank so that can clean me pipes so to speak.

Hopefully I don't have to bother with the lambda sensor (sorry I keep wanting to say lambada which makes me look like a right dopey girl at the garage !).

I really want to keep my car going, I'm not bothered about having the oldest car in my street (its def keep up with the Jones's where I live and I like lowering the tone). My car runs fine (touch wood) and has quite low milage for its age so I'd rather keep it going than get into debt with a car loan.

By the way - I was mortified the other day when my neighbour asked me how had I got away with driving without a licence all this time.....I was gobsmacked and said I passed my test first time over 10 years ago thank you very much! He said he assumed I was unlicenced cos I drove an old car...eh ? ! The assumptions people make because you chose to drive an old car and not get into debt !

Hey ho rant over and thanks for the advice - I'll let you know how I get on at the garage tomorrow.
avstar