Car faults that were difficult or have never been solved.

[PoleDriver]

My MG ZT-T 260 developed a random intermitent mis-fire. After guidance from the 260 forum and a couple of 'experts' I changed:-
The spark plugs (although they were nearly new)
The MAF sensor
The Fuel filter
The fuel pump
The COPs
Excahnged the EGR
Put it into 2 different garages for diagnostic checks
Exchanged traction control ECU
Echanged main engine ECU

Cost? About £900-£1k in total

I ended up selling it (at a low price) with the mis-fire!

Edited by PoleDriver on Wednesday 29th December 19:12

[eldar]

Newish Vauxhall Astra. Perfect, except the mileometer read KM not miles. Dealer said its just an ECU setting... it wasn't. New ECU, instrument cluster.

Vauxhall called in, another ECU, a gearbox ECU and still no fix. Eventually, a new steering column fixed it. Best guess in the end was a faulty cruise control module. Probably. Good job it was warranty...

[poing]

inkiboo said:

Actually, I have remembered another. Our Range Rover would not start properly in one space in the car park at our flat in Val d'Isere.

All other spaces fine, but park in this one and it would cough and splutter.

Not a temperature issued as it starts in -20 with no issue and the garage is only -2.

Never found the reason and just swapped spaces.

I know someone who experienced something very similar with a Mazda. He was parked up, car wouldn't start so called AA.
Guy that was coming out to sort the problem called him and said:
"let me guess, you have a Mazda or a Volvo?"
"Yeah, how did you know that?"
"I'll be there in 10 and explain"
10 minutes later guy arrives, pushes the car about 5 meters away, tells driver to get out and lock the car then unlock it. Now get in and the car will start fine, which it did!

Turns out there was some kind of transmitter and the frequency was just spot on to interfere with a particular immobiliser in just 1 side of the car park and only in a small range of spaces. Solution was to park a few meters away. The AA guy "fixed" this problem around once a month on average.

My own little problem was many moons ago when I was a student. Bought an old Micra on a sold-as-seen deal so naturally it cut out on me twice driving home, bugger! A few days of not being able to fix it myself I gave to my nearest garage who happened to be classic car specialists but were happy to look at the little Micra. Went in and the guy said:
"had this problem for a while have you?"
to which I said "no, just bought the car! I've been ripped off haven't I?"
Turns out loads of things in the engine bay had been replaced looking to solve this problem before selling up having given up. Luckily one of the guys in the garage knew what it was (carburettor gasket was made of cardboard and had deteriorated so bits of it kept blocking the fuel supply in the carb) because it was the same as some old classic he specialised in. £30 later I had a brilliant cheap little car with no work needed for the entire time I had except a couple of tyres!

[maniac0796]

varsas said:

My diesel land rover gives every symptom of a low battery, but I've now tried about 5 in it...same every time. Sluggish cranking/reluctant or no starting. Fires up fine after being jumped. Checked earthing, batteries, glow plugs, for electrical shorts, alternator (why does everyone say the alternator...surely that doesn't have anything to do with starting the car?)....I am waiting for decent weather to fit a new starter. If that doesn't fix it I will be out of ideas....

Doesn't sound like a big problem but the car is so simple it should be an easy fix...

Alternators can draw a current if they decide to pack up, so it could be flatening your battery. That's what I'm told anyway. Or something along those lines.

Have you tried changing your starter motor? Was working on a rover once that had the symptoms of a flat battery. Turned out the starter motor was just sluggish. You'd turn it over once, and it'd be dead, and then if you flicked the key again, the solenoid kicked in and turned the engine over.

[MattOz]

E46 BMW's have a problem with the dash instrumentation dimming and then returning. Every one I've had has done it at some time. No known cure.

[EK993]

Porsche 993 C2 - when the heater was running it would whistle like a kettle and dump loads of condensation into the cabin for the first 5 mins after startup - not great in the winter!

Took it to various Porsche specialists and even an OPC, nobody could diagnose the problem, and eventually ended up by saying "they all do that" (when they most certainly don't) to get me off their backs. Kept the car for 2 years and sold it without ever resolving it.

[varsas]

Mroad said:

varsas said:

My diesel land rover gives every symptom of a low battery, but I've now tried about 5 in it...same every time. Sluggish cranking/reluctant or no starting. Fires up fine after being jumped. Checked earthing, batteries, glow plugs, for electrical shorts, alternator (why does everyone say the alternator...surely that doesn't have anything to do with starting the car?)....I am waiting for decent weather to fit a new starter. If that doesn't fix it I will be out of ideas....

Doesn't sound like a big problem but the car is so simple it should be an easy fix...

It does sound like an Earth issue.
I would check the earthing again, take the leads off and clean everything.
I sorted a mates sluggish starting petrol Landie with the same symptoms as yours by thoroughly cleaning up the engine earth strap connections.
As a test try fitting a jump lead from the starter body bolt back to the battery earth.
Bear in mind it could also be a poor positive connection to the starter.

Have tried that thanks, no difference I'm afraid. The +ve cable is new (although that doesn't mean it's OK now, does it...) I will be re-doing the cables when I fit the new starter though just in case.

[varsas]

maniac0796 said:

varsas said:

My diesel land rover gives every symptom of a low battery, but I've now tried about 5 in it...same every time. Sluggish cranking/reluctant or no starting. Fires up fine after being jumped. Checked earthing, batteries, glow plugs, for electrical shorts, alternator (why does everyone say the alternator...surely that doesn't have anything to do with starting the car?)....I am waiting for decent weather to fit a new starter. If that doesn't fix it I will be out of ideas....

Doesn't sound like a big problem but the car is so simple it should be an easy fix...

Alternators can draw a current if they decide to pack up, so it could be flatening your battery. That's what I'm told anyway. Or something along those lines.

Have you tried changing your starter motor? Was working on a rover once that had the symptoms of a flat battery. Turned out the starter motor was just sluggish. You'd turn it over once, and it'd be dead, and then if you flicked the key again, the solenoid kicked in and turned the engine over.

Thanks for the reply.

I have double checked the alternator, it seems fine. There is 0 current being drawn from the battery with the car switched off, and 13.8 (ish) volts going to the battery when it's running.

Starter is the next thing I am trying, just waiting for my cold to clear/some half decent weather to do it.

[NHK244V]

If it was a ford showing those symptoms i'd say starter, especialy diesels with the high comp ratios they have.

[boobles]

my old 205gti miss firing & I never did find the cause. Replaced everything that was usggested by my friend at Pug Peformance but never did find the cause.

More recently the battery on my 328ci coupe was draining overnight & it took me weeks to find out that the Harmon Kardon Amp was staying permently "live" & draining the battery.

Edited by boobles on Wednesday 29th December 22:37

[944fan]

B'stard Child said:

Buzz word said:

I'm having a longish running issue too. I my car was consuming 1l of oil in 300miles. I took 4 garages and 2 main dealers to find the fault. It is now back at the traders garage I bought it from undergoing about the 8th consumption test. It seems to me mechanics just aren't able or allowed to diagnose a problem that requires a logical approach rather than just plugging in the diagnostics.

Modern "mechanics" = parts fitters IMHO

You speak the truth my friend, this applies even more so in main dealers I find. Got a problem, plug in the computer, ooh fault code regariding sensor X, end diagnosics, replace sensor X, charge customer, shrug shoulders when customer complains it doesn't fix it. That costs £90 per hour. Joke.

[munroman]

varsas said:

maniac0796 said:

varsas said:

My diesel land rover gives every symptom of a low battery, but I've now tried about 5 in it...same every time. Sluggish cranking/reluctant or no starting. Fires up fine after being jumped. Checked earthing, batteries, glow plugs, for electrical shorts, alternator (why does everyone say the alternator...surely that doesn't have anything to do with starting the car?)....I am waiting for decent weather to fit a new starter. If that doesn't fix it I will be out of ideas....

Doesn't sound like a big problem but the car is so simple it should be an easy fix...

Alternators can draw a current if they decide to pack up, so it could be flatening your battery. That's what I'm told anyway. Or something along those lines.

Have you tried changing your starter motor? Was working on a rover once that had the symptoms of a flat battery. Turned out the starter motor was just sluggish. You'd turn it over once, and it'd be dead, and then if you flicked the key again, the solenoid kicked in and turned the engine over.

Thanks for the reply.

I have double checked the alternator, it seems fine. There is 0 current being drawn from the battery with the car switched off, and 13.8 (ish) volts going to the battery when it's running.

Starter is the next thing I am trying, just waiting for my cold to clear/some half decent weather to do it.

Just a few things that have worked for me with old VW campers.

Clean inside of battery clamps with wire wool.
Clean battery terminals with wire wool.
Check battery terminals are tight on battery (I have found one cracked and one with stripped bolt so minimal pressure.)
Check earth and positive wires aren't corroded internally/have broken strands.
Run separate earth from starter motor to chassis, in case high resistance to earth from engine via gearbox.
Remove starter motor and clean starter motor/gearbox interface with wire wool, as this is usually where earthing occurs.
Make sure all connections are spotless and cover with petroleum jelly once tightened.

Finally 13.8v when running seems possibly a little low, but try the other stuff first, my bet would be on the battery terminals being a source of resistance as the jump starting works.

[WeirdNeville]

My Audi 80 Tdi had an incredibly annoying and occasionally dangerous fault whereby it "failed to accelerate". It would just stutter and go into a kind of low power mode at some point on long journeys after you'd put your right foot down, but with no warning lights or other signs anything was wrong. Stopping until the car was cool would cure it until it re-surfaced after perhaps a week or a month, or the next time you drove the car.
We had injectors looked at, fuel pump timings, fuel system drained and flushed, it went to several "Diesel Specialists" but no-one got to the bottom of it.

Sold it whilst being totally honest about the fault, after 18 months or so of ownership. It was one of several faults that plagued that car, but no-one had the first clue about how to sort it or even diagnose it.

[Pigeon]

944fan said:

You speak the truth my friend, this applies even more so in main dealers I find. Got a problem, plug in the computer, ooh fault code regariding sensor X, end diagnosics, replace sensor X, charge customer, shrug shoulders when customer complains it doesn't fix it. That costs £90 per hour. Joke.

If any self-diagnostic system - not just in cars - thinks there's a fault in a particular item, that item having actually failed is about the least likely cause of the reading. Much bigger chance that it's some other weirdness screwing up the signals and the system interpreting it as sensor failure because it doesn't know what else to do.

You'd think the prevalence of Microsoft operating systems, viruses, and crappy dysfunctional websites, would have cured people of this idea that what the computer says is infallible, but no, they still expect everything to be Multivac...

[mcford]

We had a lady phone us up asking if we could look at the ABS fault on her car. The car turned up and there was an invoice on the passenger seat from the local main dealer for a new ABS unit at £650, yet the warning light was still on. Three quarters of an hour later, with a new fuse fitted, the ABS worked perfectly. On collecting the car, she seemed a bit distrustfull of our diagnosis and repair.

[Hybrids]

PoleDriver said:

My MG ZT-T 260 developed a random intermitent mis-fire. After guidance from the 260 forum and a couple of 'experts' I changed:-
The spark plugs (although they were nearly new)
The MAF sensor
The Fuel filter
The fuel pump
The COPs
Excahnged the EGR
Put it into 2 different garages for diagnostic checks
Exchanged traction control ECU
Echanged main engine ECU

Cost? About £900-£1k in total

I ended up selling it (at a low price) with the mis-fire!

Edited by PoleDriver on Wednesday 29th December 19:12

A few years ago we had a Crown Victoria with the same engine, developed a missfire a few hundred miles after a service, consensus was COP's, made no difference.
Changed the NGK plugs back to the old Motorcraft ones, sweet as a nut.
Fitted a new set of Motorcraft ones and it was fine ever after.


Recent service on our V10 RV (bigger version of the above engine), fitted NGK thinking lightening would not strike twice...
Start up, missfire...
refitted Motorcraft, no missfire.
(Never before had an issue with NGK plugs in any other car)

[Big Rod]

Hybrids said:

A few years ago we had a Crown Victoria with the same engine, developed a missfire a few hundred miles after a service, consensus was COP's, made no difference.
Changed the NGK plugs back to the old Motorcraft ones, sweet as a nut.
Fitted a new set of Motorcraft ones and it was fine ever after.


Recent service on our V10 RV (bigger version of the above engine), fitted NGK thinking lightening would not strike twice...
Start up, missfire...
refitted Motorcraft, no missfire.
(Never before had an issue with NGK plugs in any other car)

If you fit a certain type of spark plug to 24v Vauxhall/Opel Senator automatics, the greabox ECU throws it's toys out.

Thank heaven for owners clubs and B'stardchild in particular!!

[Carrot]

My old car (2003 Mondeo 2.0 TDCi)

Ran beautifully from 1000 miles old to 112,000 miles old when I traded down for the corsa.

Except, every now and then, whilst driving along, the engine would "jump" briefly and the glowplug light would come up.

This was before I purchased my error code reader, so I went to a couple of good independants, and a diesel specialist with an ex-Ford senior engineer working there, nobody could find the fault and every single time, nothing was stored in the ECU.

The best they said they could do was to do a scan when the fault occured, but as that could be anywhere between 2 miles and 200 miles usually between faults, it was impossible to predict.

Ford told me that they would swap all injectors out and calibrate them (£1100!!! - nearly the value of the car at the time!), but they would not guarantee it would fix the fault.

Cars like that are becomeing a nightmare to be honest, lovely to drive and would have kept it, expensive to repair...

[Big Rod]

MKII Orion 1.6 LX. Hateful little car but other than smelling a bit of hot engine oil from time to time it went ok.

It started showing symptoms of fuel starvation right around the time I wanted to sell it. Had somone buy it on the proviso I fixed the fuel starvation.

Spoke to an ex-Ford mechanic friend of mine who told me that the internal fuel filters on the Weber carbs on them could clog up and would require cleaning out.

I didn't have a garage at the time, so had to do all the work in the street in the snow in February with a torch.

Needless to say when I took the lid off the carb' as instructed, the internals went everywhere! It took me hours to find 'all', (maybe!), the parts and put them back in some sort of assemblance of order.

The upshot was that I didn't find a filter inside so as it was early in the morning by this time and I couldn't feel my fingers, I bit my lip, shook my head, resigned myself to failure and started tidying up.

Purely by chance, I fumbled a spanner and bumped the fuel pump, (bolted to the cylinder head and driven off the camshaft!), and it wobbled. Turns out it was loose and wasn't delivering enough fuel!! About 30 seconds and a nip up with the spanner I'd fumbled later it was right as rain and the smell of oil disappeared!

<facepalm>

[marcosgt]

RX8 - If you start them, run them for a short while (not long enough to start to warm them) and stop them, the engine floods and is nigh on impossible to restart.

It's such a problem that there's a process for dealing with it (which never works) in the handbook... The answer is never to run one for a short enough period not to warm the engine a bit (it doesn't need much).

Other than that, it's a great car, but when the numpties at the 'valet parking' at Gatwick flood it after you specifically warned them leaving you with a delay that gets you home at 2:30 in the morning instead of 11:30PM, it's bloody annoying...

M.

PS Some claim the later cars don't do it, in case someone chimes in to say this is untrue

Edited by marcosgt on Thursday 30th December 09:11