UKH

Hi

My wife’s car (2011 passat) was running rough and stalling every few mins so took it to the garage. Mechanic has run the bill to £1,150 so far and the car is now running worse than ever. Not even idling. Garage has replace the MAF sensor, 4 glow plugs, ECU and O2 sensor. He now says I need a full set of fuel injectors costing up to £1,600.00 which he says he will fit for free if I source them. 
Am I being taken for a ride or is this a normal part of the diagnostic process? Wife wants to take it to a new garage and isn’t happy about paying the bill to the old place as they seem to have made things worse. They wont release the car till the bill is taken care of. 
 

Has he plugged it in to see what the diagnostics say? Sounds like they are guessing. 

The list if replacements is fairly standard most likely faults for  a badly running diesel engine. I have heard worse stories. However your 2011 Passat must surely be worth less than the repair bill? I'd cut my losses and scrap it in favour of an electric car that will never go wrong. 

Some of the items could have been dodgy and the engine still run eg. the glow plugs (diesels will start without them but may need a bit of cranking over in cold weather) the rest would all throw up errors that would be recorded in the ECU and would probably put the car into limo home mode so you'd know about them. The plugs would be easy to test and a relatively cheap repair if needed so that shouldn't have added much to the current bill. the rest sounds like the mechanic is guessing and I'd be concerned that even after changing the injectors you wouldn't have a running car.

I'd be tempted to try to come to an agreement with the garage to pay for the parts they've replaced and not the labour. The problem is that most people and garages aren't very good at defining the contract when they drop off/accept a vehicle for repair and I've had garages do unrequested work and then spring bills on me when I come to pick up the car, even after I've asked them to get in touch with a quote before doing any work.

Nearly spat my beer out laughing at that!

It does seem a bit of a cheek charging £1k+ to make the problem worse. Did they advise that it might not solve the problem when they undertook the work?

It'll be easier if you can come to an agreement with them, eg that they replace the injectors on a no fix no fee basis. You'd need to be reasonably confident they are actually going to fix it though - and suggesting sourcing your own parts wouldn't exactly fill me with confidence.

Otherwise, you'd probably need to pay them (and possibly try to recover the money later) and get the car collected and try your luck somewhere else. How badly do you need the car back..?

Here's a possibility from a "keyboard mechanic" - my bro in law has an audi a4 diesel (someone has to) which startyed running rough. Cutting out, going into limp mode, just being naff, and expected a big bill. Took it to one garage who sucked their teeth, muttered about injectors, EGR valve etc, and mentioned £1,500 - £2,000. Abnyway, after a couple of weeks he decided to bite the bullet, called up a different garage that he'd been recommended who collected it with instructions to do it between jobs and as cheap as poss. He got a phone call two days later saying fixed, when do you want to collect it? Total cost £230 inc collection. Wow, says bro in law, what did you do? Changed the battery, mate. Whenever we get a modern turbo diesel, especially VAG , first thing is to change the battery. Apparently a run down and old battery can cause all sorts of shenanigans. Not saying it'll cure tyours, but worth a try......if it doesnt work, you will be able to send the battery back for a refund.

E2A - the car has been fine ever since (4 ish months ago).

I wish my car had this mode.

It's inconceivable that all those parts needed replacing. Was the fuel filter and fuel pump checked? Has the car been serviced on time? I wouldn't trust that garage with any further work. 

A 2011 Passat will be worth fixing. 

No fix no fee for an unspecified 'rough' running 12yr old Passat is a new engine, exhaust, management system and all sensors. Might be into the fuel system as well. There's a reason nobody does no fix no pay.

It's ideal for the taller climber who needs a vehicle to sleep in but can't stretch to buying a van.

First of all, you're in a crappy situation I'm afraid. So sorry you find yourself in this position.

Your mechanic is only expected to provide reasonable skill and care. His repairs based on a quote do not need to be fit for purpose since there's no way to be 100% sure their diagnosis is correct. Unfortunately the customer takes the risk here.

Replacing glow plugs is a separate issue to the rough idle and stalling.

No idea how he got you a new ECU for that price. Must be a second hand unit.

One issue is the fault codes won't say, this is broken, replace this part. It really gives you the symptom, and quite often it's hard to track down which component is causing that symptom. 

Wrong. He means you "may" need....... What's impossible to know if if he's carried out all the basic checks first. Has he checked the fuel pressure for example? What about a smoke test to ensure the inlet is all sealed.

I agree that he's guessing and he's slowly working through things in order that he thinks is causing the problem. Somebody more familiar with these cars will likely get to the answer quicker.

I can be. You might just be unlucky and it's a bit of a pig to diagnose. it happens. The fact that he's willing to fit new injectors for free is a sign of good faith and that he means well I think.

If they've done the work they said they would do, and you agreed to have it done on their recommendation then you owe them that money. Remember, reasonable skill and care. You would need to prove that they didn't do what an experienced mechanic would have done.

I wouldn't expect them to.

Nightmare garage scenario ! Has he got the bills to show that all that work has actually been done (ie. new parts installed ) ? My sympathies. Car repairs are getting worse with sophistication.

Our Berlingo HDi didn't have a problem of this character, but it had OBD problems for several years which have given no practical problems in running, but the diagnostic light gave failure at MOT checkup. I eventually got a recomendation for a garage which I would not have otherwise considered - well away from the daily journey. Happily they quickly resolved problems for 50 quid. Sensor failure which no-one else could find. The moral to this story is that sometimes it pays to search out the best equipped and experienced garage.

Yes we were recently very pleasantly surprised how much a Passat (62) with 195K on the clock and lots of dog hairs was worth.

Yes I've had a few but I've never kept one that long - I usually bottle it at 120k ish!

Thanks for all the advice hive mind of UKC. Lots of varying opinions on the subject.

Just to clarify, we’ll certainly be paying the man his money. I trust that he’s done the works and replaced the parts (ECU was second hand), but it’s very annoying that I have  to pay over a grand for what seems like nothing.

Further info - there was an error code for the MAF sensor. Once replaced the code persisted so he recommended new ECU. Once fitted there were new error codes for glow plugs and O2 sensor. No codes showing since these were replaced cleared. He did say AFTER he had replaced the ECU that the next set of repairs might not fix the issue. I pointer out that we couldn’t go on forever replacing parts but I just got a mumble and a shrug. 

I can’t think of many other areas of life where the customer has to pay money with no guarantees. I understand that diagnosing these things can be difficult, but surely the car manufacturers and garages can put their heads together and come up with something better. 
 

Had a very similar experience a year or so ago.

Car was running like a bag of spanners so took it in. We agreed what the probable issue was and rough cost (£200). A week later and a bill of £1500 with the problem not fixed and car now not running I was quoted more costs to resolve the problem on top of bill.

After a week or two of us both digging our heels in they agreed to buy the car from me (2012 diesel) and I ended up getting a similar amount as if I was selling private and way more than a trade in for new car. (This was right at the beginning of 2nd hand car market rocketing so both of us walked away amicably).

It was a very stressful few weeks though with seemingly nowhere to turn other than duke it out as civil as possible. Feel your pain and good luck! 

Assuming your fuel and air filters are good, then get your mechanic to have a look inside the EGR valve and throttle body valve. If they're gunked up then they won't be opening and closing properly which can lead to the symptoms you describe and may well have thrown up the error codes indicating glow plugs, MAF sensor, O2 sensor etc. 

Speaking from experience on my T5, so a similar VAG TDi engine.

TBH with a rough idle/stalling I'd be a bit surprised if they haven't already had a good look at the whole air intake system, so they might have already ruled this out.

How much is a 12 year old Passat that isn’t even “a good runner” worth? You could just leave it cluttering up the garage and see what happens.

If he is talking about fitting new injectors free of charge I would recommend getting him to pull the injectors out and taking them to an independent injector specialist for testing yourself.

I did the same with a Golf MkIV TDi once. They garage didn't have a fecking clue what was up with it and seemed fairly reticent to look at it after it had amassed several hundred quids worth of investigation.

I didn't pay up, they didn't chase me. I just left the thing there and haven't been back. That was about 10 years ago...

I now make sure I take my VAG diesel cars to another place that is a bit more specialist.

This all day long, I was recommended a garage local to us so I called in to see them and see if they were interested in taking on our vans. 

We had a chat and I told them if the 3 garages we have used in the area, his reply was "we are a lot more expensive than them but we are worth it" 

Been with them 4 years now, they are more expensive per hour than the other places I used but they work faster so the bill is only a bit more, the parts are more expensive but they use quality parts and not cheap stuff and the single most important thing, in 4 years I havnt had to go back with a problem once. A van off the road costs me a lot of money, paying a few quid more to do the job once and do it right works out far cheaper overall. 

Why?

I hope you get it properly diagnosed. Do let us know how the story ends.

Is said garage a VAG specialist? If not it sounds like you need to take it to one!

Just to add another to the battery post above, my T5 started having issues starting, taking 3 or 4 tries, throwing glow plug warning lights, oil pressure, going into limp when it eventually started. I talked to a few garages and had glow plugs, injectors, fuel pumps etc. suggested were the issue.

It ended up being sat around for a while anyway for a few reasons so I decided to charge the battery with a proper (not trickle) charger, started first time and does every time the battery is charged, seems the battery is knackered....

There's a dead EV out the back of our workshop waiting for the courts to decide it's fate, €35k estimated repair costs.

I don't get this. If time allows, a slow trickle charge is always the way to go. They often have functions for reconditioning the battery which is nice.

Faster charging options do not offer a more complete charge, and only serve to heat the battery and cause more off gassing. Fine for the occasional charge if you're stuck and need it charging quickly, but the default should be a trickle charger.

Tesla model 3 I think.

Did it set itself on fire?

A new battery is in the order of $16k and that's the most expensive part. What the hell broke on it?

I would think carefully about this conclusion, a charged battery should do the job regardless of how it has been charged.

If a vehicle is starting soon after coming off a "bigger" charger it is possible that a temporarily higher voltage is masking the fault.

Possibly it isn't the most expensive part, part of the discussion is whether a repair to the chassis structure is permitted. It came in for an MoT (Tüv for us) and apart from the common front suspension and brake problems the tester failed it on corroded and distorted rear battery pack mounts. The insurance assessor then found cracks in the battery, a fault in the high voltage system, faults in the 12v system (because the car leaks in the rain) and who knows what else. It's a write-off but can't be moved until Tesla remove the battery so it sits there fenced off until the courts decide who's paying.

Somewhat ironically it belongs to an alternative energy consultancy, they drive hydrogen company cars nowadays (privately the boss has some mad AMG Merc).

If it has zero value can I have it?

It apparently does, and also depends on the general condition of the battery (see tale of my Bro in laws Audi based woes upthread). It seems cars these days are much more sensitive to battery performance, and according to his mechanic, VAG suffer more than most from this. In the "good old days", all a battery did was turn the starter, light the lights and provide a spark. all of which it could do if a bit knackered, just not as well as a new one. Now there are all sorts of clever bits to power that are much more sensitive.

Exactly this.

Surely they can put it on a flatbed with a Hiab and take it to Tesla's workshop?

A multi stage charger will do a far better job with a battery than a trickle charge.

https://www.victronenergy.com/media/pg/Blue_Smart_IP67_Charger_manual_230V/...

I didn’t mean how it’s been charged fixed the problem, I mean the fact it’s charged, the charger shows me the voltage of the battery when it starts it’s charge cycle and it’s lower than it should be.

Higher voltage masking a fault? Like what for example?

Damaged battery = dangerous goods and it has to be transported in water. As it has a failure in the high voltage circuit as well only Tesla can touch the car, normally they send guys to do the work but the argument is who pays.

What voltage is the battery holding?

At the simplest level you could have a starter motor that is slightly below par, beyond that there will be sensors that can send rogue signals and trigger faults  as they start to break down. An intermittent fault on a cam or crankshaft position sensor can cause the problems that you describe.

Hopefully it is a failing battery or starter but there are so many things that can cause issues on modern engines.

You're comparing apples and pears.

I was talking about charging slowly (trickle < 3 amps) vs charging fast (up to 50 amps).

You're comparing smart vs dumb chargers.

You can get smart trickle chargers.

My CTEK 5.0 is a bit of a border case at 5 amps but I would still consider it s trickle charge albeit a smart one. 

Charging a lead acid slowly is the best way to charge one. Sure, there are times where you can charge it faster with no (or very little) detriment such as when the battery if quite drained, which is what the higher power smart chargers do, but it doesn't improve the state of charge when complete. It just achieves it quicker.

This.  I had an older Skoda which had problems with the power steering not always working, the electric windows temperamental, other random warning lights. Fitted a new battery and all those issues disappeared.

Which reminds me I should get the battery checked on my current car (also a Skoda).

Potentially anywhere where the power delivered is simply regulated by the supply voltage or diminished below acceptable limits when it drops. With a duff battery (or bad connections), voltage will collapse under load. Things like glow plugs, solenoids/actuators (some injectors, access control) pumps and power assist (fuel, coolant, vacuum, PAS, active suspension etc), heated sensors (O2 and possibly airflow although that should be well regulated), even the alternator which charges the battery needs a healthy battery/connection to work properly

I'm a little sceptical but it wouldn't be the first time built in safeguards end up being more trouble than they prevent.

jk

I think we are essentially saying the same thing, a battery that isn't in top condition will case issues with systems as it can't deliver a high enough current at the correct voltage, especially when cranking a starter motor, ergo an improperly charged battery can cause issues, which is what i was trying to say.

A CTEK 5.0 isn't a trickle charger, it will charge the battery as it sees fit based on its condition at time of connection:

STEP 1 DESULPHATION
Detects sulphated batteries. Pulsing current and voltage, removes sulphate from the lead
plates of the battery restoring the battery capacity.
STEP 2 SOFT START
Tests if the battery can accept charge. This step prevents that charging proceeds with a
defect battery.
STEP 3 BULK
Charging with maximum current until approximately 80% battery capacity.
STEP 4 ABSORPTION
Charging with declining current to maximize up to 100% battery capacity.
STEP 5 ANALYSE
Tests if the battery can hold charge. Batteries that can not hold charge may need to be
replaced.
STEP 6 RECOND
Choose the Recond program to add the Recond step to the charging process. During the
Recond step voltage increases to create controlled gassing in the battery. Gasing mixes the
battery acid and gives back energy to the battery.
STEP 7 FLOAT
Maintaining the battery voltage at maximum level by providing a constant voltage charge.
STEP 8 PULSE
Maintaining the battery at 95–100% capacity. The charger monitors the battery voltage
and gives a pulse when necessary to keep the battery fully charged

Yes an improperly charged battery can cause issues but you really need to test to make sure that this is the most likely answer.

Otherwise you can easily find that a new battery works for a while and then drops you in it at a later date if it turns out that the real issue lies elsewhere.

I would be looking to check the voltage of the battery immediately after charge, when the battery has rested for a while after charging, with the ignition on but wothout the engine running, whilst the engine is cranking before it fires and whilst the engine is running.

A trickle charger literally just means it charges at a low amperage. So yes it is. It's a smart trickle charger.

https://www.repco.com.au/know-how/CTEK-Battery-Chargers#:~:text=All%20CTEK%....

"All CTEK MXS battery chargers are perfect as a trickle charger for your vehicles"

Or if you want to do a little background reading:

https://www.lifewire.com/what-is-a-trickle-charger-534853

"The term "trickle charger" refers to a battery charger that charges at a low amperage."

There's even a section on "Smart trickle chargers" if you scroll down.

It doesn't mean any more than that. The fact that the CTEK 5.0 has a recon setting and can adjust it's load doesn't stop it being a trickle charger.

OK, so it has trickle charge mode, but if you want to call it a trickle charger then that's fine.

I'm quite interested to know what you think a trickle charger is. 

A trickle charger won't turn off or change its mode when the battery is charged.

I think you've just made that up. There are plenty of smart trickle chargers on the market that do switch off and change output depending on battery condition and call themselves trickle chargers. 

But each to their own.

Erm, i really haven't, a trickle charger it its truest sense is just that, it trickles voltage at a low current on the battery permanently.

But each to their own.

What concerns me about the battery diagnosis is that in the OP it was stated that the car runs rough and stalls regularly.

If the battery is bad enough to drag the voltage down to the point where it will cause faults whilst the engine is running I am really surprised that it is capable of taking enough charge to start the car at all.

I dont think any charger will sort this - the battery appears no longer fit for purpose. There have been several posts on here giving first hand experience of VAG cars having all sorts of problems that were cured by fitting a new battery.

To OP - It sounds like this garage are fumbling in the dark where several other garages (certainly in the caso of my Bro in law) just start with the battery and then if that doesnt work, look elsewhere. It seems that is the MO of a lot of them....

It will and does - i have my bike on a charger like that all winter........seems to work a treat.

Maybe the battery is OK but a connection  to some module has corroded (high resistance) which would pull the voltage down and cause all sorts of gremlins. The possibilities are endless! You can see why techs just keep swopping parts!

The problem is when you have a weak battery that's just strong enough to start the car, it results in the alternator having to run a bit harder than normal to compensate for the lower than expected battery voltage.

This then in turns causes voltage swings in the alternator (I have no idea why). And if electricity gizmos hate anything more than low voltage, it's erratic voltage. The car may well be averaging 14.4V when running, but it's the erratic behaviours of it that's the problem. The car battery should absorb these spikes, but I believe (and I'm not sure about this bit, a weak battery may struggle to do this). Anybody know why?

I don't think low voltage is a problem for most cars. I had a Jag, complicated car, with a knackered alternator once. As it was a big job to change [had to undo engine mounts, and jack the engine up], I kept putting it off, so wired up three batteries in the boot as a temporary measure. It ran fine. Drove to and from work, but dropped to about 8 volts once and didn't quite make it home. Everything cut out at once. I was basically destroying those batteries I suspect. A running car will be nowhere near 8 volts with a working alternator so I don't believe a weak battery resulting in low voltage can be the issue.

The reason I'm sceptical it's the battery at all is I would expect one of the first things a mechanic will do is try it with a booster pack on.

Agreed but it appears to have been an issue for a few people. It may not be the battery per-se, it could be the act of replacing it cleans up the connection to the car's 12V bus. Who knows, while it seems an unlikely fix to me, it's not impossible.

jk

There's lots of confusion here over different types of charger, almost certainly because there's no agreed naming standard and the norm has changed a lot over recent years.

A traditional car battery charger would have been a mains>15ishV transformer, one (or more) diodes to make a DC (ish) output, a fuse and an ammeter if you're posh. Often also a switch to change the output voltage by adding or removing a few turns. On low/slow you get something like the battery float voltage, what it will withstand long term connection to without off-gassing though using it like that would be unwise. Fast/high is set to deliver enough current for a fast charge, transformer coils limit the current, user terminates the charge. Super crude but it works fine.

Modern maintenance/float/trickle chargers have microcontrollers managing their output and are much more sophisticated and accurate. You get features like temperature compensation, current and voltage limiting and restoration programmes (pulsing current).

They can all be reasonably described as trickle chargers (when not set to fast!). They don't all do the job equally well.

jk

That's not how it works, as batteries deteriorate their internal resistance deteriorates until it is effectively an open circuit, the alternator charges briefly but once the 14.4V is reached it stops, with a voltmeter this reads as a fully charged battery but the moment you load it you see it drop dramatically. A battery tester applies a massive load and measures the batteries ability to cope, this is also what the BEM system uses, it looks at the voltage when cranking over and says whether it's good or not. Once the engine is running (if the alternator is functioning) then the car will always be receiving the correct voltage no matter what. The exception is if the alternator fails to excite which is very rare ( and normal jump starting usually prevents this) or the battery has actually dropped a plate which is unheard of nowadays.

In anything built in the last decades with a coded battery system a weak battery causes the vehicle to go into what my friend calls "2001 syndrome" alluding to the film where the computer prrogressively shuts off functions to preserve the core elements, with VAG this starts at seat heating and stops before steering, locks etc die.

Unless they have improved significantly in the last 20 years I wouldn't hold much store in a battery tester if my experience is anything to go by. 

A van I had often struggled to start, 3 different garages tested the battery and declared it fine, they kept trying g things but thd problem persisted. In the end I bought a new battery, end of problem. 

This is pretty much the correct answer . It’s virtually impossible to hit the correct solution first go so the correct procedure is to work through a sensible / correct sequence . If you took your mechanic to court they would argue that’s what they had done.  The reason that there are less and less garages prepared to do this is that the bill starts to rack up and then people do t want to pay it . If they had just tried random stuff you might have a case but it really doesn’t sound like they have .
 I had an old knackered diesel Passat estate as a stop gap between good cars a few years ago , 56 plate , it came with enough mot to last until my new car arrived , i havee an excellent local guy who kept it going for the four months or so I needed it but was very clear that to turn it into a runner to sell on would easily cost 3k and was really not worth it . It “only “ had 110 k mikes on it which he thought was very low for it to be as “ f@&ked as it was .