MOT – am I being taken for a ride?

[Dave HalfordParticipant @davehalford22513]

I had a swelled up carbuncle of rot once which you could bounce the round end of a big ball pein hammer off all day, but one light tap from the pointy end of a welders slag hammer caused total disintegration of thick black rust and a big hole.

I have had an MOT test from a guy who used such a hammer and he showed me how. So not everyone follows the rules, but people could reasonably claim that paint damage from previous tests could have caused the premature rot so hence the rubber hammer and Mk1 calibrated ear to detect the different sound.

[Mark RandParticipant @markrand96270]

I had a Mk2 Renault Espace (lovely cars, like driving in the open, where's so much window). The MOT testig station had recently taken a lad on, who commented that the front nearside door panell was rusting (it was startig to delaminate). I didn't want to believe me when I said thar GRP doesn't suffer from rust untill the boss grinned at him and explained how Espaces and Reliants were made.

[Robin GrahamParticipant @robingraham42208]

Posted by Nick Hughes on 16/09/2022 10:24:56:

Just seen this thread and as the owner of a 2007 Astra H for just over 5 years, means I've had the same faults as the OP over the years.

Fortunately I do all my own repairs and have a multi system Scan Tool to read and reset the various system fault codes.

Going through the faults in order:-

1) Heater Blower not working

This is usually caused by :-

a) Failed (Or Partially failed) Resistor Pack , This was the fault with my blower.

b) Failed Selector Switch

c) Failed Blower Motor

Both a) and c) are accessed by removing the Glove Box, b) is accessed by removing the switch panel, so no need to interfere with the instrument cluster.

2) ABS Fault and Non functioning Speedometer (As mentioned early on in this thread, these ARE linked)

The ABS sensor is in a ring attached the wheel hub and senses something in the Wheel Bearing.The wiring connectors all have Mechanical interlocks so unlikely to work loose (actually a pain to get undone). Corrosion of the Driveshaft CV joint outer, or of the Wheel Hub housing are the usual cause of failure. As the sensor wiring passes very close to the CV joint, the rust flakes can damage the wiring or sensor.

Although the sensor ring can be sourced online, the wheel hub and bearing has to be removed to fit, so although more expensive and as most motor factors don't carry the sensor in stock, the whole hub is replaced.

The Speedometer uses the Nearside ABS Sensor for it's speed information, so in all probability this is the one that has finally failed.

Hope this helps.

Nick

P.s. Just finished changing BOTH front springs after one was found broken on Mondays MOT.

Edited By Nick Hughes on 16/09/2022 10:34:05

Thanks Nick – that does help. It looks like my suspicions of skullduggery on the part of the garage were unfounded.

It's going back there tomorrow – arm and a leg I fear, but probably cheaper than buying an new old car.

If the Director of the People's Bank of China comes through though, I don't need to worry. He's sent me a charming letter saying that Hubert Graham (no doubt an uncle I'd forgotten about) had a fatal accident whilst in China and, as I'm the only living relative, he would like to transfer Hubert's assets (amounting to 1 million USD) to my bank account if I will give him full details. Bit of luck eh? I'll be able to buy a Tesla.

Robin.

Edited By Robin Graham on 20/09/2022 01:28:44

[peak4Participant @peak4]

Posted by Michael Gilligan on 16/09/2022 10:27:09:

Thanks for sharing that, Nicholas

… it’s water under the bridge, but do you happen to know if there is a specified procedure for using that radiused scraper at the end of the handle ?

MichaelG.

I think it's probably covered in Appendix A HERE, as well as the use of a small screwdriver.
https://www.infrastructure-ni.gov.uk/sites/default/files/publications/infrastructure/appendix-a-structural-integrity-and-corrosion.pdf

See HERE for the greater manual
https://www.infrastructure-ni.gov.uk/publications/light-vehicle-inspection-manual-dva

Bill

Edited By peak4 on 20/09/2022 02:27:13

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for the lnks, Bill

I remain convinced in my own mind that the dealer in question found use of that tool ‘convenient for the purpose of passing’ a vehicle that he was selling … but I shall never know for sure.

A little like ‘blueprinting’ an engine or exploiting loopholes in the Formula 1 regulations, I suppose !!

My ‘learning point’ was, of course, that I will never again rely upon an MOT certificte that was issued by the seller of the vehicle.

MichaelG.

[Steve NeighbourParticipant @steveneighbour43428]

Posted by Chris Crew on 14/09/2022 08:15:55:

Modern car electronics are a riddle wrapped in a mystery inside an enigma to me. I had, apparently, one LED fail in a rear light cluster on a Volvo V90 which brought up all sorts of intermittent and contradictory fault indications on the dashboard. The local Volvo specialist (after many years no longer an authorised Volvo dealer) had it in the workshop for a week before they found the fault and charged me £675. Obviously, I had no choice other than to smile through gritted teeth and cough up.

Some time ago I had a similar and equally weird issue on a LR Discovery 3. while driving north on the M6, there is a 'bing and the dashboard lights up like a Xmas tree and the message screen states 'gearbox fault/failure' and the car went into 'limp mode'

so 40mph to the nearest service stop, call the AA, and the technician duly arrives in 35 mins (I'm impressed with that) after plugging his laptop in and looking at the fault 'codes, he is then on his phone to their tech help guru, and then he wanders back and starts taking a rear light module apart, looks at one of the brake/tail lamps, throws it in the bushes (literally) and fits a new bulb, asks me to drive a couple of times around the car park.

Lo and behold, it is all fixed with no warning lights/messages so I ask what was that all about – he said a bulb 'element' had broken, and every time I braked it was shorting out and this caused the gear box ECU to throw a hissy fit

Never in a million years would I have guessed that one, and I doubt the LR dealer would have either !!!

[BazParticipant @baz89810]

.Steve thanks for that information, I am an owner of a Disco 3 and I shall make a note of that one in case it ever happens to me, up till now most of my faults have been suspension related so gearbox and bulbs are overdue to catch me out

[martin haysomParticipant @martinhaysom48469]

i used to weld these old bangers. a lot of customers would say if the MOT man did not fail it don't weld it usually happened when i was asked to patch a outer cill and told them the inner was rotten. MOT tester can not fail what he/she can't see.

[john halfpennyParticipant @johnhalfpenny52803]

The D3 brake light bulb issue is very well known – I suggest you follow the Disco 3 forum. I've just reluctantly parted with my D3 after 17 happy years.

[John Doe 2Participant @johndoe2]

In my many years experience in live television broadcasting and home vehicle repairs, I have found that about 70% of electrical and electronic faults are caused by bad interconnections.

Then about 20% are caused by blown fuses, 9% by bad power supplies and finally only 1% by actual failed electronics.

My car suddenly came to a shuddering halt one day, with the instrument warning lights all lit up. I was literally yards from my home and the engine did restart, sort of, so I was able to limp home.

Then, according to the above, I disconnected all the electrical connectors on and around the engine*, sprayed them with switch cleaner spray, and reconnected and disconnected each one several times, to clean the pins. All was then well, and the car has been fine for years since.

If I was the OP, I would check relevant fuses, and clean connections relating to the ABS, and then remove the instrument cluster and clean the connector on the back, as above*.

There are sources of vehicle wiring diagrams on-line – you can buy just a one day subscription and print off whatever you need.

Sadly, even in this day and age, a female taking a car to a garage can still fall victim to the males in some garages thinking they can rip her off because they assume she won't understand the technicalities and will meekly pay up if they tell her something needs doing.

Secondly, many main dealers, do not have proper engineers working in their garage any more; they have "technicians" but all they do is connect a scan tool and change whatever the scanner says is not working – colloquially known as 'loading and firing the parts cannon'. Usually though, whatever is not working is only due to a bad ground or bad supply, and the unit itself is not faulty. Unplugging the supposedly broken unit and plugging a new one in frequently cleans the bad connections in the plug, which is what clears the fault. However, meanwhile you have paid hundreds of pounds for a new unit, when the original one actually still worked perfectly, if only the interconnections had been cleaned.

*I cannot take any responsibility if you copy what I do, but you could potentially save hundreds of pounds of garage bills.

WD40 make a good switch cleaner spray.

[Robin GrahamParticipant @robingraham42208]

Thanks for your suggestions John Doe 2. Sound advice I'm sure, but I don't have anywhere to work on the car any anyway even 'simple' instructions such as 'remove the instrument cluster' baffle me.

Saga so far – the car went back to the garage this morning and they rang this evening to say it was all fixed at a cost (according to my wife who took the call) of £39.73. I can't believe that – I think she must have misheard – but we'll see tomorrow when we pick the car up.

Robin.

[NealebParticipant @nealeb]

Maybe they threw in the labour free as a goodwill gesture, and that's the price of a can of WD40 with garage markup?

[Robin GrahamParticipant @robingraham42208]

Well, I should have listened to/ acted on advice given above – the £39.73 was for 0.4 hrs labour + parts to replace two fuses. Think I could have managed that myself .

They still haven't done the blower – now awaiting a quote for that, but apparently it can be accessed by removing the glove box. So I'll have a go at doing that myself – seems simple enough (in principle!).

Thanks again for discussion, Robin.

[Jim GuthrieParticipant @jimguthrie82658]

Posted by John Doe 2 on 21/09/2022 12:15:47:

In my many years experience in live television broadcasting and home vehicle repairs, I have found that about 70% of electrical and electronic faults are caused by bad interconnections.

Then about 20% are caused by blown fuses, 9% by bad power supplies and finally only 1% by actual failed electronics.

My car suddenly came to a shuddering halt one day, with the instrument warning lights all lit up. I was literally yards from my home and the engine did restart, sort of, so I was able to limp home.

Then, according to the above, I disconnected all the electrical connectors on and around the engine*, sprayed them with switch cleaner spray, and reconnected and disconnected each one several times, to clean the pins. All was then well, and the car has been fine for years since.

The garage which serviced my Vauxhall Omega estate some years ago on one occasion took the dashboard out and checked and cleaned every connection behind it. They had a term for it which I have now forgotten, but they told me they found it necessary to do it fairly regularly to get rid of electrical "funnies".

On a similar vein, way back in the 70s I was driving a BBC Film Unit Hillman estate in the Inverness area when the temperature gauge went hard over into the red and stayed there. My colleague and I checked under the bonnet and there didn't seem to be any obvious signs of overheating. So we contacted base and they told us to take it to a certain garage in Inverness to get the car checked over. When we got there the management decided they were going to deal with it since it was BBC vehicle complete with insignia and they had been contacted from BBC Glasgow. They had the vehicle for an afternoon and we were told that they tried everything and couldn't clear the fault. We decided that we would take the vehicle and drive on very carefully. As we were leaving the garage, the garage electrician, who had been ignored throughout the proceedings, whispered to my colleague to check the earth contact behind the centre of the dashboard. We got a mile or two down the road, dug around behind the dash, found the terminal and gave it a clean, and lo and behold, everything worked properly.

The garage did not charge the BBC but we thought that the electrician should have got something, even if it was only bragging rights over his bosses.

Jim.

[HowiParticipant @howi]

Posted by Nick Hughes on 16/09/2022 10:24:56

P.s. Just finished changing BOTH front springs after one was found broken on Mondays MOT.

Edited By Nick Hughes on 16/09/2022 10:34:05

Interestingly, I had a Golf that had a broken rear spring, just before the 3 year warranty expired, dealership replaced only the broken spring, had it been out of warranty, they would have said BOTH springs would need to be replaced to keep things in balance!!!!!!!!!!!!!!!!

[CirclipParticipant @circlip]

'Floating' earths account for mysterious faults on all forms of equipment. Had a Ford Escort 1.6D years ago. Turning LH indicator on, part way through the corner, the 'Ticking' would stop and restart when going straight again. Binnacle switch? No, turned (bad pun) out to be bad earth on LH rear light cluster plug. Earthing is first thing to check on trailer electrics to fix some weird lighting faults.

Regards Ian.

[Nick WheelerParticipant @nickwheeler]

Posted by Circlip on 23/09/2022 09:51:14:

'Floating' earths account for mysterious faults on all forms of equipment. Had a Ford Escort 1.6D years ago. Turning LH indicator on, part way through the corner, the 'Ticking' would stop and restart when going straight again. Binnacle switch? No, turned (bad pun) out to be bad earth on LH rear light cluster plug. Earthing is first thing to check on trailer electrics to fix some weird lighting faults.

Bad earths on old cars were common, especially for the lights. They often earthed every nearby component through a couple of wires to a screw into sheetmetal. My fix on most of my cars that suffered from flickering, dull or other intermittent lights was to weld an M6 bolt where the screw went, and to add separate wires from each component. Washers, a nyloc nut and copperslip retain them. In every case, that solved each problem that wasn't caused by the useless Lucas bullet connectors.

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