Another Rimmer Rant! I've broken my leg so have plenty of time to kill - sorry!
I am a "garagiste" here & operate a small workshop next to my house. I don't work too hard but am busy enough working on expats' cars & a few local French owned cars. Most car owners are on a tight budget & I am busy enough (& I would like to think honest enough) not to create work. Many cars built over the last ten years rely quite heavily on computer diagnostics to locate faults which sounds a good idea - except it's not!
Older cars tend to be quite simple. If it won't go it is usually because there is no fuel or no spark so a simple series of tests will usually isolate the problem. A replacement part can then be fitted if necessary. Newer cars are far more complicated. The basic functions are the same but in order to better control fuel burn to reduce emmissions the computer needs to analyse engine parameters, such as engine rotation, air flow, fuel mix, fuel pressure, throttle position, air temprature... the list is huge. Each item that needs monitoring requires a sensor to tell the computer what it needs to know. These sensors can be quite delicate and can easily fail in a hot, dirty, vibrating engine bay. Sometimes this will result in a worrying light appearing on the dash with the instruction to visit your dealer & sometimes the car will just stop, then the light will come on.
The dealer will plug in his diagnostic computer to read the faults (50 euros) & the betting is that it will say that a sensor is faulty - which means that your engine is in perfect working order & would power you round the world had the computer allowed everything to work! On some cars a build up of metal dust on the crankshaft motion sensor - yes, the computer needs to be told that - is enough to blind it so if the computer does not think the engine is going round there is no need for the fuel pump to operate. With no fuel getting to the engine you go nowhere! Some of these failures mislead the diagnostic computer. If no fuel is getting to the engine the fuel pressure sensor will tell the computer that it is not registering. Most garages will just replace the offending sensor (at least 300 euros). The faults will then be cleared & you're on your way - until the fault recurs.
I have a 2002 Renault Laguna here which I bought from a Brit. It has a fuel injection problem & now will not start. He was not a customer of mine choosing instead to use the man dealer when the fault first appeared. Over a 2 year period he spent almost 8000 euros with them as they tried to rectify the fault. He has had a new fuel pump (600 euros), various pressure sensors, 2 cam belts ( within a few months!), assorted motion sensors - a long & expensive list! When an expensive component was replaced & found not to be at fault he was not offered a refund. He therefore had to pay to have a perfectly good component taken off his car & thrown away!
Apart from the unfairness of this there is the worry that the diagnostic computer does not diagnose correctly. Any fitter can keep changing parts at random until the car works without the expense of a computer!
There is also the environmental cost of this. The old perfectly good components are disposed of. Whether they are recycled or dumped is immaterial, there is the cost in pollution terms of transporting the unnecessarily produced waste to its final resting place & the same in manufacturing an unneeded component, packing it & transporting it to a garage.
It gets worse! A customer was unlucky enough to buy a peugeot 307 from Belgium through a rogue who offered to register it here for them. He said he would need the car for this (he didn't). Whilst swanning about in it the turbo developed a fault & consumed all its oil, resulting in a siezed engine. The "warranty" apparently did not cover the engine! To cut a long story short I ended up with the job of finding another engine & fitting it. One was obtained from a salvage yard for a reasonable price & duly fitted. When the car was tested ther was a small water leak on the oil filter cooler, an aluminium bit the size of a sardine tin which had probably been damaged in transit. It is held on to the plastic filter housing by 4 screws. A visit to the main dealer revealed that, although the cooler & housing are 2 distinct parts, you have to buy the whole assembly - 280 euros. I had the small leak soldered for 20 euros. Another component that need not have been made. After a road test the car only ran on 3 cylinders - the diagnostics correctly pointed to no 2 injector not working correctly. A new one can cost 350 euros + fitting. These are coded so you cannot fit just any old one but a luck would have it one was found on Ebay. So a set of injectors for this car would be over 1500 euros, enough to make you wonder if it is worth doing especially as the car drops in value. Ford are worse although some engines are shared with Peugeot. On a 2005 Transit each injector nas a unique code which has to be programmed into the vehicle's computer so if one has to be changed it can only be done by a Ford garage with the correct computer. Coding each injector has nothing to do with the vehicle's operation & can only be a money making act. These things are already overly sophisticated & this extra coding adds a potential area for faults. It is not unknown for a computer to forget the code causing a breakdown. Sometimes reentering the code will correct this but I doubt this is often tried. More unnecessary expence!
And worse! Many vehicles with hydraulic clutches now have a sealed system. In the old days if your clutch master cylinder failed to pump you could replace the rubber seals. Then you had to change the whole master cylinder. Now, on such vehicles as a Freelander you have to change the whole system - master cylinder, slave cylinder, resevoir & connecting pipes - as a single part! So now you buy 4 parts to repair just one. 3 perfectly good bits for the landfill, then. Very green - not.
Had a new clutch recently? If you have a fairly modern vehicle you may have a "dual mass" flywheel. For the first 100 years of motoring cars had a flywheel made of a single lump of steel & it worked very well. Then some bright spark came up with the totally silly idea of nailing two flywheels together with little springs, supposedly to take any vibration out. I can never recall vibration being a problem! With the new design the springs stretch & break, allowing the whole thing to wobble & rattle, causing premature wear of the clutch. A replacement flywheel can add 600 euros or more to the cost of a new clutch, which can last as little as 30000 miles. This is such a problem that some manufacturers offer an old style flywheel as an alternative replacement part!
Another recent job was to fix a Peugeot which lacked power & the computer kept coming up with "anti pollution fault". After much investigation I noticed that the air hose would collapse on acceleration. The turbo was blowing, but not enough. Rather than waste time the car was taken to a main dealer, who diagnosed a siezed turbo & quoted 1500 euros to fix it. This turbo was not siezed & was not old so anothe avenue was explored. This Turbo was a variable vane type, the amount of blow being adjusted by a vacuum controlled lever which can ingress water & rust. It can be replaced but involves the removal of the front subframe & the new lever has to be set up on Peugeot's computer. I hired the mechanic & his machine & he set it up. After reassembly the fault was the same. The only thing left was the electronic vacuum valve which activates the lever. 60 euros for the part & 5 minutes to fit & the car was back to normal. So much for diagnostics!
My point is not to boast about how good I am (I've made the odd mistake myself) but how bad manufacturers can be, & how the motorist can unwittingly pay huge prices for a simple job & never know. A Renault Clio which would not start most times but when it did it ran rough could have cost over 1500 euros to repair had the owner left it to his local dealer. The immobiliser was reset & the EGR valve removed & cleaned - 90 euros - & is in every day use.
I could go on giving examples all day.
Cars cause more pollution more when they are built, repaired & scrapped than they do in everyday use. Lots of parts are being made & changed needlessly. I cannot support this with figures because no one is checking this.
Manufacturers are making us buy more than we need - why not replace the faulty bit rather than make us buy a whole assembly?
If a diagnostic computer cannot do its job then don't use them.
A little honesty goes a long way & its no wonder sales are dropping so much.