I invite backroomers to post the automotive design faults which have caused them the most misery and probably expense. One old and one new might make interesting reading, if only to see if the automotive industry have learnt any lessons.
Here are my two for starters - they're both electrical:
Old: - The wonderful SU electric petrol pump.
New: - The seemingly random elecrtical failures which are caused by solder fatigue. These range from the famous VAG "Relay 109" to the failures of instrument panels (usually in parts), switch panels and some ECUs. The German manufacturers seem to have more than their fair share of these.
Solder has no strength in fatigue - 6 bends and a stick of it is broken. Badly designed electronic assemblies suffer from fatigue as they are thermally cycled - the stress reversals ensure premature unit failure due to broken (not dry) joints.
659.
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It'll take some time for a considered reply but I remember my old Moggie thousand. The electric pumps ticking provided a surefire diagnostic code a couple of ticks at start up was ok, rapid ticking at start up indicated that a software update was required, this was usually installed by opening the bonnet and slapping the thing with a screwdriver until the "correct" codes were restored and it started up as it should (unless a 1001 other reasons not to start were present of course)
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It'll take some time for a considered reply but I remember my old Moggie thousand. The electric pumps ticking provided a surefire diagnostic code a couple of ticks at start up was ok rapid ticking at start up indicated that a software update was required ...
What about no ticks at all?
I've a few examples of SU pump failure so I'll dust this one down for you.
After I ineptly skated Mum's Moggy GWR 597C into a wall one Christmas Eve, she decided she would have a brand new unrepaired one. HWR 44J duly arrived with an often-silent SU pump. There were no spares to be had, apparently (what we had to put up with in them days!) so I rigged a length of stout wire between the pump on the bulkhead and the heater valve control on top of the engine block. When the pump fell silent and the engine hiccoughed the driver would tug on the heater control. The shaking of the fuel-starved engine always rattled the pump into life. This was a summer-only solution you understand ...
Hawkeye
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Stranger in a strange land
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There you exactly what I said - early diagnostics, the difference being you could actually fix it. I could actually smell my old Moggie when I was reading that.....strange thing memory. Taught me all I know about RWD though !
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Old:
The standing oil filters on later BL 'B' series engines (they had the opening facing down). A joy to change, if you could convince whoever you were buying one from that their application lists were wrong, and that you DID need one with a non-return valve.
New:
Early Focii rear seats. Mine had a one-piece squab that couldn't be lifted with the front seats fully back (I'm over six foot), and a split backrest.
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659
You're right about solder fatigue - that's now probably the cause of the greatest number of premature failures of any single fault.
I'm not so sure that the SU electric pump had a design fault - 'though the mechanical one certainly did.
Although it was many decades ago; I don't remember changing many premature failures. Hundreds of breakdowns - yes; but mainly after a long service life. Are our memories being slanted by the fact that these now appear most on very old British classics?
Maybe if the VMs had specified the service life of a set of contacts, [as I believe Rolls did?] then even those incidents would have been seen as simply lack of required maintenance?
I can also forgive some temperamentality of components if the "fix" is merely percussive stimulation. Even a new set of contacts was a roadside job - not so easy with a potted ECU.
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VAG group brake light switches. How can you design one to fail "on" when that its not its natural state?
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TourVanMan TM < Ex RF >
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TVM
Good one; I can't think of another component where it's SOP to order at least two....
...As the first one will break as you install it if you don't!
Designed by a moron.
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Ford rear light surrounds circa early 80's.
They would become porous and eventually when you used two lights at once e.g. brake light and indicator... they'd all short and try to work at once, but with somewhat reduced voltage.
had a double glazing fitter mate do mine with silicone sealant which worked a treat...would often see other cars with the same problem
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TVM: >> VAG group brake light switches. How can you design one to fail "on" when that its not its natural state?
Unless I've misunderstood, surely a brake light switch that shows the lights on failure is the right way around? Then any following traffic can see they're on constantly and it's clear that either you're really braking or the lights aren't working properly. Plus you may spot the extra light at the back (at night) looks odd. Otherwise, if it failed to off, brake sharply and somone may crash into the back of you.
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Escort boot lock. When I used to own one, everytime I leant into the boot I would hit my head on about 2 inches of catch hanging down from the hatch.
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Underslung spare wheels on Citroens and Peugeots. If you lived outside of a gated estate with resident security gaurds the spare was unlikely to survive the attentions of the local chavs, who could spring the cage in about two seconds. It also meant that when you got a puncture the spare was covered muck which rapidly transferred to yourself and your clothes.
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The wheel bearings on minis. Ball bearings should never have been used on these, used to change mine just before every MOT.
More recently, the power steering pump and waterpump on my mondeo tdci, leaking water from one to the other.
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I read often, only post occasionally
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Those awful Solex carbs on some MkII Golfs that would ice up at the drop of a hat, and that seemed to suffere clogged injectors with alarming frequency too. Absolute pig to get set up properly, especially as they seemed to change with the weather..
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Generations of brand new British motorcycles used to sit in showrooms with drip trays under the engine because the factories could not bolt them together and make them oil tight. Even a decade after the Japanese showed them how to do it properly, Norton, Triumph and BSA carried on with the age old tradition of total loss lubrication.
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The cooling system and head gasket of the Rover K-series engine.
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04 Grand Scenic 1.9 dCi Dynamique
00 Mondeo 1.8TD LX
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Old:- FIAT body work (1983 Uno)
'New.:-The plastic impellor in the water pump of the 1.8 20V Audi engine (as fitted to the A4 and others)
S6 1SW
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Folding driver/ front passenger seats forward to let passengers into the back seats of 2-door cars- and the seats do not go back to the same place either requiring a giant or midget to fit! Especially true of previous grand vitara 3 doors/soft tops.
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I should think this one will run and run. It seems extraordinary that so many designers omit the simple precaution of asking a few customers what they want. For example -
Rear visibility (Honda Civic and Renault Megane, to name but two) - I still think that it would be very easy to run over a small child while reversing in one of these - all for the sake of looking 'cool'.
Handbrakes - there really is no problem with a pull-up handbrake between the front seats with a button on the end. The Mercedes foot-operated parking brake (C-class and above) and various electronic brakes are answers to a non-existent problem. Just this week SWMBO was completely put off a Saab 9-3 by the handbrake button being underneath the handle - simply so that the silly stylist could have a straight edge to the centre console. That may seem petty - but it isn't if you only drive such a car occasionally (as SWMBO does with mine).
Starter buttons - fine if you have keyless entry but (for example) the Honda Civic and the BMW 320 require you to insert a key and then press a button. Why?
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Head restraints that only come up far enough for average drivers - fully extended they're just at the height to cause fatal brain stem injuries for above average drivers in a tail end shunt. This is both an old and new problem as manufacturers (excluding GM) just don't learn.
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current Vauxhall indicators......i find them infuriating. Why change an accepted industry standard set-up for something that you now have to do differently? I've forgotten how many times i'll indicate and then realise half way through the manouever they've turned themselves off. Then at other times i'll drive down a road with the left ones one, then the right ones, then the left ones, desperately trying to centre them again...Idiots.
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i'm having an anti- Vauxhall 5 minutes.....
current Vx Astra opaque inicators.........you can hardly see them in sunlight......ridiculous...why?
and the awful stitching on the plastic seats, that fool no one that they're not really leather
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The brake light bulb failure warning system on some Vauxhalls which operates on the basis of the brake light switch being activated so if one bulb fails it tells you though if the switch fails, as opposed to the bulbs, the brake lights do not work at all. The driver is unaware because the system simply "thinks" that the brakes have not been applied and the switch not activated so offer no warning so also giving the driver a false sense of security.
These systems shoud be fail-safe!
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Cheddar,
SWMBO had a GTE that did this, all the warning indicators went out after a self-test apart from the brake light failure light, that went out on first application of the brakes, I never understood it either, she said it promoted her into doing a brake test before driving off properly, she still does this even now...
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Space saver tyres....a waste of space
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Not at all. However bottles of goo and an electric pump are.
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TourVanMan TM < Ex RF >
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Sorry TVM, I agree with Galad here.
What the hell do you do with the full-size wheel you've just taken off when your boot's full?
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Sorry TVM I agree with Galad here. What the hell do you do with the full-size wheel you've just taken off when your boot's full?
I would love that dilema. My current (not for much longer) has no spare of any kind. What do you do when the goo and pump fails to fix your tyre with a hole in it?
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TourVanMan TM < Ex RF >
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Ford Anglia 100E and series, Pneumatic windscreen wipers that stopped wiping when you accelerated and needed them most. Fixed with the 105E Series as witnessed by Harry Potter.
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Land Rover - most of the cab design faults that the 1955 version has were still present and correct in 2005 ! The new one still had a couple as well, at least they made you feel at home !
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I love my old MBs, but it has to be said that it is a rare M103 or M104 straight-six engine (1980s-1990s) that has not seen a failed head gasket and leaking from the timing-chain cover (both usually 70k onwards, although some have failed earlier). That was surely a design fault and it seems sadly ironic that it should feature in engines representing the last in the line of a design originating several decades earlier. However, these failures seem generally to be undramatic and plenty of those engines go on for tens of thousands of miles with the driver ignorant of the problem, or in denial, or consciously choosing to ignore it.
You can add to that the failure of the wiring harness that has hit early 1990s MBs (not just the W124 E-class). That appears to have been because of a switch to eco-friendly insulation material that proved not up to the job.
Not much newer, but I was disappointed when the rear-axle bushes on my 1996 Mk III Golf VR6 needed replacing at 43k. My mechanic reckons it is a Golf weakness that has survived in the Mk IV and possibly beyond.
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Remember when Ford finally entered the late 20th century by fitting an engine with an overhead camshaft but forgot to give it a proper oil supply? That was one of the memorable sounds of the 1980s - the thump-thump-thump of another knackered Pinto.
Of course that was when it was running after you'd managed to get it started thanks to the Ford version of automatic choke technology...
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and while we are on Fords, the DMF on my '01 Transit. Especially the idea of putting the clutch slave cylinder inside the bell housing! Brilliant. all the garages I spoke to said only a silly person would do a clutch job without replacing the slave cylinder. I guess thousands of perfectly good slave cylinders are flung into the bin because of this?
Papho
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"Current Vauxhall indicators......I find them infuriating"
Not only Vauxhalls - BMWs have them too, at least on the 3-series (I can't vouch for the other).
Poor old Vauxhall often gets a knocking, usually from people (including me, I admit) who drive Vauxhalls only occasionally. People who own them usually seem well satisfied.
To criticise a BMW is almost like lese-majeste, but I'll do it all the same. As well as the indicators, the 3-series has that stupid seat height adjuster where you have to heave yourself up bodily to lift the seat. There are many far cheaper cars with an easy ratchet handle. And the 5 and 7 series have windscreen wipers set up for LHD.
I'm sure this all seems petty, but if you do a highish mileage as I do you have to live with these things every day. Or if you drive the car occasionally, as SWMBO does with mine, you have to remember the quirks instead of concentrating on the driving. If a car feels right as soon as you get in for the first time, it'll probably stay that way.
In terms of design faults, VAG and Toyota are out in front as being the least quirky of all that we've tried in a number of recent test drives.
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Lets go back 50 years to the Morris Minor.....
It may have been a design icon, but who engineered the fixing of the brake master cylinder inside a box section and then fitted bolts which strictly needed the the whole OS front suspension dismantling before you could remove the bolts! OK that was the official method of removal. Most people learnt that with a little persuasion you bend the torsion bar sufficiently to remove the bolts and reverse using half nuts and reducing the length of the bolts with an angle grinder. But it could leave you with a Front suspension knock. I never heard of a torsion bar failure after this abuse, but I guess it may have happened.
and move forward 20 years to the Hillman Imp....
the only car I have owned where it was quicker to take the whole engine and gearbox out than change the no 4 spark plug. You had to change it regularly unless you used a different grade of plug in that position because that cylinder ran colder?? by design! Nobody sold plugs on a set of 3+1 basis!
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pmh (was peter)
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And the radiator was placed exactly where it would pick up all the clag and encourage overheating - not that it needed much encouragement.
To be fair (just in case l'Escargot sees this) the Imp did push forward the science of automotive troubleshooting by a couple of decades. ;-)
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Passat Pollen Filters!!!!!!!!!!!!
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C4 - key lock only on passenger door, disaster if you drive without the remote key
- dark dashboard function that works great except if the main beam is on, its dash indicator blazes in your face like a 500w halogen lamp
new MX5 - cup holder in the door that fouls your leg if you're > 5'8"
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Cup Holders - What are they for ? (apart form cups, does anyone use cups anymore, let alone drive around in cars with them)
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The American market threw a wobbler at the original cup holder design on the MINI - they couldn't fit their buckets in them, led to a load of debate and a redesign. Was a major thing for them. But then they ask you questions like would you like the 32oz coffee or the large (with acknowledgements to Bill Hicks)
Can't believe the new MX5 has the holder where it is though. Was seriously looking at one but just couldn't get comfortable. Besides anything else not sure if I'd want a cup full of coffee or coke in the door ready to drench/scald me if I was driving enthusiastically. As Alistair Campbell would say, the designers aren't "serious"
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Nissan Micra current and previous model
The terrible Nissan Micra horn press that uses the center of the steering wheel instead of the end of a stalk.
You have to find the right spot to press/thump hard to make it work (not easy). By the time you do manage it, it is too late.
Why they waste money on something so complicated that works so poorly escapes me.
Ditto the black plastic door strips that are an extra that are instructed/designed to be fitted so low down as to be useless at stopping door scuff marks from other car doors.
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How on earth could I have forgotten the celebrated Passat plenum chamber blockage/pollen filter seal debacle. The "beauty" of this design fault is that not only does it wet the car and ruin the carpets, but the designers have by a stroke of pure genius put a huge chunk of expensive electronics on the floor at the lowest point.
Halmer my dear fellow, go to the top of the class!
659.
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As Honest John mentions in one of his latest columns, and a bugbear of mine: Headlight and other bulbs that can't easily be changed without removing the bumper or otherwise disassembling bits of the car. It's not rocket-science - blown bulbs should be easily changeable at the roadside without any tools, even by a novice with no mechanical skills.
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Rear seats that will not fold down if the front seats are pushed back - with the result that anyone over 6' tall would find so little room in the driver's seat as to make driving very difficult.
A problem on various cars - in particular Renaults, in my experience.
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blown bulbs should be easily changeable at the roadside without any tools even by a novice with no mechanical skills.
I could not agree more, and in the Scenic I have one of the worst examples of it. Only one bulb (o/s dipped) is accessible without removing the entire front bumper assembly and even doing that removes most of the skin from one's knuckles.
I would like to see legislation to prevent this kind of appalling design.
Cheers
DP
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04 Grand Scenic 1.9 dCi Dynamique
00 Mondeo 1.8TD LX
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>> blown bulbs should be easily changeable >> at the roadside without any tools even by a novice with no mechanical skills. Scenic
Are you totally sure DP?
There was someone on here moaning about spending hours dismantling the front of a Mondeo however RTFM would have told him that there are two pins that enable each light unit to be removed in two minutes.
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Are you totally sure DP?
Oh the Mondeo's fine, cheddar. Done all front bulbs in that now, and none took more than 5 minutes. As you say, the lights pop out in minutes, and all the offside ones are accessible without even doing that.
The Scenic however is a different kettle of fish altogether. Why they couldn't design a quick release mechanism into the lights is beyond me, especially as they've gone to incredible lengths elsewhere on the car to make it a pleasure to live with.
Cheers
DP
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04 Grand Scenic 1.9 dCi Dynamique
00 Mondeo 1.8TD LX
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Sorry DP, I knew that you were not referring to the Mondeo, just using the previous post pon here as an example, regards.
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Old and new: self-cancelling indicators. Just what is wrong with.... switch appropriate indicator on - complete manoeuvre - switch indicator off?
Reliance on the self-cancelling bit probably explains why so many get left on.
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Old: - The wonderful SU electric petrol pump.
And the scary thing is that this design of pump is still used on small piston aircraft - Cessnas and the like.
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The design of front brake calipers on Peugeot 106/Saxo where the pads are retained by two long (8cm) pins. If the pins were stainless.... but they are not and they corrode and stick and are a real pia to remove. Versus the Ford?BMW designs which use a simple and much easier design.
The multipart hoses used by PSA which inevitably break at the joins/or the weaker bit splits.. and new hoses are>£30... all could be avoided by the use of a bit of steel pipe (which woulrd rust of course...
ALL French electrics/electronics. Especially connections and siting of key connections.. usually in aplace where they WILL corrode.
ALL 5 cyclinder Fiats where the engine has to removed to change the cambelt.
Any Renault. Full stop.
madf
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The wonderful SU electric petrol pump. And the scary thing is that this design of pump is still used on small piston aircraft
Same design needn't mean the same pump though. The components may well be more substantial and of better quality in an aviation application. There might well be some sort of dual or back-up pump too.
Someone with specific aircraft knowledge may correct me of course. But the tendency of certain car components to fail or wear out after a certain period has as much to do with cost-cutting in manufacture as innate design flaws. No mechanism is everlasting and service and replacement schedules for civil aircraft are fairly strict.
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They are the same pumps but now made by companies such as Facet. However you are correct in that they are inspected and replaced more frequently.
Point I was making is that most parts on a 'modern' small aircraft is 40 year old technology. Another example is the use of single grade engine oil. New fangled multigrades (15W50) are only just creeping in on the scene!>> >> The wonderful SU electric petrol pump.
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Two of everything on small aircraft. Magneto (none of this coil ignition rubbish!), plugs, fuel system. Except the thing most likely to go awry. Pilot.
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Renault Clio 2001 with electric windows.
If you wash your windscreen or it's raining and the passenger/driver window open just a fraction, water drips right into the electric window switch both sides.
Maybe it's the odd weather us Roast Beef keep getting!
Like the post!
Chris
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Good to see Audi have continued this tradition. If I open windows to remove rain before setting off then reverse down the drive with the window still open I can guarantee a soaking as rain pours off the roof onto the window switch!
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Windscreen wipers not set up properly for RHD on many foreign cars; BL even fitted them the wrong way round with both RHD and LHD models!
No standardised operation of minor controls (flasher, horn, indicators) until very recently: Alfasud, older Mercs and Peugeots the least intuitive. Remember Ford's foot-operated wash/wipe?
Flat batteries from cars with headlamps and other electrics NOT wired through ignition.
Fiat electrics from the year dot.
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Minis - just the whole car really - !
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old faults? bits or rubber to clean the windshields in cars capable of 40 mph in the 1930"s
new faults? er- bits of rubber to clean the windshields of supercars capable of 242 mph
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Ford/PSA 1.6 Diesel engine (fitted to new Focus/cmax/Volvo S40 Diesel.)
Design fault means that every now and then the starter won't engage properly in the flywheel ringgear when you try to start it. Result = horrible crunching noise and repeated attempts to start. Long term effect is the flywheel teeth become rounded off which means fault happens more and more often until one day car won't start at all.
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Old fault. My first car was a ford 100E popular 1172 side valve engine ,3 speed gearbox. the worst feature was undoubtably the vacuum operated wipers. Slow uphill and manicly fast downhill.Coasting down Harrow hill one day they just flew of completely ,arms and all! The most ridiculous piece of design I have ever encountered though must be on a Saab93?circa 1973.I locked the two front doors by pushing the buttons down(via the back doors)then locked the back doors in the same way,Result you cannot enter the car at all.Keys dont work.
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