Dashboard lights, eh? Who'd 'ave 'em.

I'd far rather have one for the alternator, one for the indicators and one for high beam, like the way it used to be.

I'm not likely to have the Aero Cauldron light come up on Mrs Audi because she doesn't have a particulate filter to clog, but she makes up for it in different ways.

Halfway to Suffolk, on our most recent trip in early September, the old girl decided to throw an engine management light. On steady; no urgently flashing 'if you don't stop now I'll put a rod through the block, Buster'.

Thankfully.

Since an EML can be the result of at least 1,943 different faults, some intermittent, some permanent and one or two depressingly terminal, we pulled off to investigate. Since I didn't have my diagnostic scanner with me, investigating involved opening the bonnet and checking that the engine was still there.

It was.

The next thing was to call Green Flag. Mrs Le Pew and I filled the next 60 minutes with a little impromptu how's-your-father in the caravan, and opened a packet of post-coital Jelly Babies.

Actually, only one part of that is true.

After a couple of mobile calls to the by now en route recovery operative to explain in the most minute detail where we were located, I saw him hurtle past the end of the lane we were parked in.

Forty-five seconds later he reappeared. A youngish bloke; bright, cheery and very helpful.

He plugged in his perpetual combobulator and after going through the menus for engine ECU, airbags, appetisers, entrées, suspension settings, desserts (including a tempting cheeseboard selection featuring some of the very best English cheeses), traction control, ABS and ESC he proudly showed me that the fault was a 00575 intake manifold pressure limit exceeded (intermittent) one.

Once we discussed the potential causes and possible ramifications of this (and the fact that the EML hadn't been flashing in its Extreme Peril mode), we decided that the optimum course of action was to clear the code and continue our journey.

This we did, but not until we'd thanked him and patted ourselves on the back for remembering to renew the breakdown cover in the first place.

The fault didn't reappear.

Until the other day.

My daughter and I were on the way to Grandma's house for an overdue visit last week when I noticed a distinct flat spot in the car's acceleration as we approached the transition to supersonic. If it had been a forty year-old petrol-engined car, the first thing I'd have done would be to assume it was a bit of crap on its way through the carburettor jets or a whiskery plug and made a mental note to clean and re-gap the plugs when we got home.

This car isn't one of those cars. We continued on with my passenger unaware but with me being just a little apprehensive as Mrs Audi had never done this before.

Half an uneventful hour later, somewhere on the A42 in the vicinity of the exquisitely-named Ashby de la Zouch, the mighty six-cylinder plant suddenly lost all boost and the power disappeared. Changing down to get the engine back in its power band had no effect.

We pulled into the Co-op car park in Ashby a few nervous minutes later, about halfway between home and our ultimate destination of Tadcaster, North Yorkshire.

I opened the bonnet again, checked the security of as many of the many vacuum hoses as I could without removing any ancillary components while Jo (my daughter) took the dogs for a wee on the car park regulations sign. And several other places too.

Decision time. The car started and idled without so much as the tiniest hiccup. There were no warning lights on the dash.

Do we press on towards the grim Northlands and risk breaking down completely on the artic-swept hard shoulder of the M1or M18, or do we turn back, hoping that if we did grind ignominiously to a halt it would be rather nearer the safety of home?

We chose the latter. I drove gingerly, half hoping that she'd throw another warning light which would at least mean that a fault would be logged in the ECU, and one which would enable a diagnosis of the problem.

And about ten minutes later, she did just that. The same steady EML, but with no other symptoms.

The other day was diagnosis day. A new scan at the local independent I use revealed the same 00575 code as before, but the revised pudding menu now included banoffee pie, which was an unexpected bonus.

The garage owner, an ex-VAG technician and all round top geezer checked everything he could check; all the hoses, the play - or lack of - in the turbocharger bearings, the turbo boost control actuator linkage and how well the induction system was holding its all-important vacuum.

We discussed his findings at some length.

There weren't any.

There were several things it could have been - and might still be, but nothing concrete. One possible culprit stood out, something which was later backed up by me performing an assiduous Google search of that fault code.

That part was the turbo boost control solenoid, more colloquially known as the N75 valve.

He said the best he could hope for was that the car misbehaved somewhere handily close, because there was clearly nothing to be gained by throwing new parts at it.

We discussed it some more. The thing is, he didn't charge me for either the scan or the subsequent investigation, two things which would undoubtedly have cost me the thick end of two hundred quid had I been barmy enough to take it to the closest franchised dealer.

He's that kind of bloke. If he can't fix stuff, he doesn't charge. He's the kind of mechanic who is worth his weight in gold.

In my case that may well be because I take three cars to him for routine servicing, repairs and MOTs, and he knows full well that it won't be long before I'm back in his door, my wallet stretched as wide as the fully-distended cervix of imminent motherhood.

So I reckoned I was in credit to the tune of quite a lot of money, and in light of that decided to get him to replace this pesky N75 valve anyway. I decided this on the basis that there was a better-than-evens chance that it was causing the infuriatingly intermittent fault, that it would need replacing at some point anyway because they just fail, because doing it would at least remove it from the list of things that could have happened, and because a new one was quick to change and not very expensive at all.

He did it yesterday.

Who knows what's going to happen now?

Zitat

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My daughter and I were on the way to Grandma's house for an overdue visit last week

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I trust she was carrying the regulation basket and wearing a red, hooded cloak? Did you have your chopper handy?

You raise a lot of interesting points. Your reference to an older petrol-engined car, for example. Yes, they were easier to understand and easier to fix but, boy, did they need some maintenance to keep them running sweetly. In my youthful years oh so long ago I seemed to be forever cleaning, gapping and changing spark plugs that now need changing every 60,000 miles or so; setting points dwell angle (what?) and strobing the timing marks on the crankshaft pulley. On a Morris Minor Traveller I had, countless grease nipples needed attention every 1,000 miles or the steering would collapse and the prop shaft would seize. I was amazed to discover that Mrs G's Honda Jazz (which has 8 spark plugs incidentally and many garages only ever find the front ones) needs its tappets adjusting every so often. When did any non-classic owner have to do that? And what about decokes?

For the most part, modern cars are incredibly reliable. They are to all intents and purposes maintenance-free with sensors compensating for such things as fuel and air temperature (no more choke controls); fuel octane rating via the anti-knock sensor etc. The problem is that when they do go wrong the diagnosis (as you found) can be a problem and the fix can be expensive. Oxygen sensors can be a real pain and as the technology improves the potential for electronic things to go wrong increases.

My daughter had a top of the range Vauxhall Zafira 2-litre diesel that 99% of the time was a superb car. Occasionally, however, usually when climbing a hill and often when in the fast lane of the motorway, the engine management light would come and the car would lose power and go into 'limp-home' mode. It scared the life out of her. It happened to me once when driving the car in France and It really shook me up. The solution was to stop, turn the ignition off and then restart the car which might then behave faultlessly for another 5,000 miles or so.

The Vauxhall dealer was rubbish. The fault code indicated 'swirl flap' failure. Swirl flaps are pollution control butterfly valve devices fitted in the inlet manifold of some cars that operate at idle speed to mix incoming fuel and diesel so as to give better combustion. In some BMW diesel engines these flaps fail, disintegrate and are ingested into the engine converting it to instant scrap.

She part exchanged the Vauxhall for a petrol Mazda.

Your mechanic sounds great. Let us know how you get on with the new valve.

Had a few problems like that with my Ford Galaxy.
The first was what appeared to be a loss of turbo on the way back through France. It turned out to be the air flow meter. The size of a matchbox, the cost of a vintage Cartier lighter.
Next, we were on our way to a gig in Aberystwyth. Half way there "the throttle cable snapped". Easy thought I. One stout piece of cord coupled up and running through the dashboard. Bonnet open. What throttle cable???? Remedy, shut down the engine, wait for a few minutes and re-start. All clear and OK to go on. When back home the eventual replacement of this piece of kit, this time located under the foot pedal was really cheap.
Next, and next, and next...various relays started to give out. Engine wouldn't start, windows would wind down of their own accord etc. Cheap to purchase but a sod to fit as the fuse box was buried under the dashboard.
Eventually I decided to swap the best car I had ever owned. After all, she had done >150,000 miles for me.
R