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Design faults in major manufacturer car engines

While pondering something else which I don't need to go into I started thinking about all the non trivial design and machining faults that seem to creep into OE car engines despite the amount they spend on R&D. Here's a listing of some which spring to mind.

Ford Crossflow - Uneven machining of the valve spring seat depth from one end of the head to the other (only an issue with modified engines though) Ford Pinto - cam lobe and finger wear Ford CVH - cam lobe and lifter wear Ford CVH - excessive cylinder bore wear Ford 2.0 DOHC - cam chain breakage Ford Zetec - hydraulic lifter pump up and 'valve sticking' Lancia Gamma Flat Four - cambelt breakage and bent valves with steering on full lock (one cam drives the PS pump) Peugeot 205 1.9/1.6 - cylinder head bolt threads in the block stripping when the head bolts are torqued up to OE specs Peugeot 205 1.6 only - cam lobe and lifter bucket wear Rover K series - cylinder head gasket failures Triumph TR6 - excessive crankshaft thrust washer wear Vauxhall XE 2.0 - porous 'lost foam' cylinder head castings leading to oil and water mixing Vauxhall V6 - porous oil/water intercoolers Vauxhall various - cambelt tensioners breaking

No doubt there are many others - by all means list your own.

Seems to me you rarely/never get the OEM to hold their hand up and admit to any of these even though they are well known in the trade. It strikes me that OEM fault claims should be recorded and made publically available and that once a fault exceeded a certain level of claims (maybe 1%) it should be deemed a design fault and be repaired FOC even if the car is outside warranty period. That might keep them a bit more honest. Of course you get recalls on safety related issues like Mercedes A classes falling over, Firestone tyres exploding etc but never on engine/gearbox or similar components.

Reply to
Dave Baker
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Oooh, can I add some?

Renault Megane II 1.6 K4M - coil packs burn out frequently Renault Megane II 1.6 K4M - TDC sensor mounted on cylinder head and above clutch, where it breaks down due to heat levels. BMW V8 (did it affect other BMWs too?) - Nicasil cylinder liner coatings attacked by sulphur in petrol.

Brian.

Reply to
Brian Ruth

In news:8098a4e64c% snipped-for-privacy@avro.anat.ucl.ac.uk, Brian Ruth decided to enlighten our sheltered souls with a rant as follows

well, if we're adding stuff

VW Golf Mk5 - everything Volvo 7**/9** autos radiators leaking water into the auto trans oil cooler VW Golf Mk4 - coil pack failures Rover 2300 / 2600 - camshaft wear due to sticky oil relief valve Peugeot 205 / 309 GTi - clutch release arm pivot breaks Jag AJ6 / AJ16 engines - head gasket failures...

Reply to
Pete M

Most of the failures that are listed above are actually caused by poor or low maintenance, in particular all the cam wear ones are IME caused by insufficient/incorrect oil changes.

Best recent one I know is the land rover diesel engine, the oil pump was improperly bolted in on quite a few engines, after several years it falls off. Land rover refuse to pay out. To check whether yours is ok is several hundred pounds worth, a rebuild is several thousand, you decide. This affects approximately V reg discos.

mrcheerful

Reply to
mrcheerful

Nah .. far too reasonable and fair to their customers .. that would never be permitted.

Reply to
Mike Faithfull

Those aren't really engine faults, though? Sensors seem to fail on every make.

Ally block sixes too - although the V-8s seemed to suffer more. Probably because they run hotter?

Reply to
Dave Plowman (News)

Also,

All VAG 4 and 6 cylinder (especially 20v and turbos) cars coil pack failure, and on selected 4 cylinders, throttle body failure. On TDi's MAF sensor failure, and some petrols now too.

Ford Endura D and DE's- cambelt failure.

Tim..

Reply to
Tim (Remove NOSPAM.

ford focus zetec early tensioner failure, half the cambelt change milage

Reply to
Jon

Which engine?!?!

Reply to
Tim (Remove NOSPAM.

I think it was a 1999 1.6

Reply to
Jon

The problem ???? The word "FORD" springs to mind

JK

Reply to
JK

In news:ch07l7$k7$ snipped-for-privacy@kermit.esat.net, JK decided to enlighten our sheltered souls with a rant as follows

Ahem...

Reply to
Pete M

VAG 3 cylinder petrol too.

Pete.

Reply to
Pete Smith

I thought the 1.6 & 1.9 heads were pretty much the same? Or it that the earlier 1.6 105bhp engines?

The oil pump spocket on the Pug XU9 engines not having a woodruff key, being held in by friction always felt a bit iffy to me.

Tell me about that one! My first coil death killed my cat too, which bumped the price of repairs up a lot.

I'll try and remember that one for future, thanks!

I managed to get that cross-threaded somehow, which required some rethreading. It feels like a too small a bolt for the job.

Reply to
Davemar

The heads are the same. The 1.6 cams have chamfered lobes which reduces the width and increases the contact forces. Maybe there is also a material spec difference but I have no way of telling. I have to assume the narrower lobes are at least partly responsible for the fact that many 1.6s suffer lobe wear and very few 1.9s seem to.

Reply to
Dave Baker

Henry Ford.... The man who made walking a pleasure

Reply to
JK

My addition to the list is the Renault F9Q 1.9 diesel engine which allows the aux belt to get jammed up in the timing belt path if it ever snaps. So a simple belt can take out the whole valve train with it....

Reply to
Ebodsky

Land Rover also cocked up on the 300Tdi engine with the mis-alignment of the cambelt pullys resulting in belts snapping on some engines.

Reply to
Simon Barr

The message from snipped-for-privacy@aol.comNoEmails (Dave Baker) contains these words:

Clio sunroofs leaking. Takes about an hour to fix once you know what you're doing. The original gasket is a joke, and there's no drainage, it just relies on the water overflowing across the roof. It's a thin foam thing about 1/4" across, easily compressed and prone to staying compressed. I took it out and replaced it with silicone mastic and cleaned it off neatly all round. Hasn't leaked since.

Reply to
Guy King

Pug/citroen tu3s engines.....intake manifold bolts directly to head with no gasket as standard. Water ports leak into intake ports causing misfires upon starting. (The twin carb manifold is water heated).

Bmw m20 engines (mid 80's).....prone to head gasket leaking between cylinder 5 and 6 if the gearbox top bolts are overtightened (after clutch replacement or crankshaft seal change).

ZF-4HP gearboxes uses in many bmws/peugoets in the mid 80's .... prone to wearing out in seconds if the engine is reved hard in neutral!!

Reply to
Mr Fix It

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