Warranty Repairs - Turbo, Coolant Leak, Engine Wiring Harness (not covered-£350)

[MikLSP]

Today I had my first dealings with the VW warranty on my Golf as I took the car in to Lookers VW at Preston for investigation of the slow coolant leak and the turbo siren noise (something I didn't realise was a bad sign until the other day).
I was a little disappointed to find myself being fed precursors to cop outs all the time and lined up with several potential charges of £65 for investigation but when I was told that the turbo would be looked at and usually only replaced in the case of sudden mechanical failure, I had to voice my dwindling faith in this warranty.

Anyway, as it happens, my prior scepticism was not fully warranted (pardon the pun) and I hope to be getting some good news tomorrow. They tested the turbo and found "enough to mean there shouldn't be a problem" when putting it to VW for a new one so I am very hopeful that I will get a call tomorrow to book it in again.

The coolant leak was unfortunately not yet resolved as no leak was found and the system passed pressure testing. Obviously coolant IS going somewhere and they have agreed to test the system again but can anyone suggest what is the most likely problem and why no pressure is lost? Is it simply such a small leak that the pressure test would need to run for longer to detect it?

I also asked them about the front wing corrosion which is starting to show but I forgot to follow this up so I will have to ask again when the car is next in.
As an unfortunately sour end to the day,  upon taking the car back I noticed a texture on my leather steering wheel that I had not felt before. Sure enough, I found the following nasty scratch at the 9 o'clock position:


I went straight back and in fairness there was no dispute and I have been told it will be sorted which I sincerely hope it will.

So, a mixed bag today but I will certainly be happy about getting the turbo replaced, has anyone else had theirs done on warranty?

EDIT: A Short time after my first visit, I had a dash warning on the car saying "Engine fault Workshop!" along with the glow plug light flashing amber. VAG-COM shows a couple of sensor faults, boost pressure and intake air temperature, and the engine runs Ok but feels underpowered.
This is now going back in for additional diagnosis and hopefully to be resolved quickly.

[MJ]

That looks like someone with a wedding ring on May have caught your wheel.

My front wings were both beyond repair but had been previously bogged so vw wouldn't even entertain a pair of replacements. Common issue though and the company who supplied my new ones said they sell a couple of pairs a week.

[DDM]

if the engine's using coolant but has no visable leaks, i'd check the front floors firstly to see if the carpets are wet, (faulty heater matrix) or secondly i'd say possible headgasket, ask if they can remove the plugs and put the camera into the cylinder and see if theres one that's far cleaner than the others, is there any sign of water out of the exhaust?

[MikLSP]

My first thougt was a ring but it looks like it may have been something heavier like the edge of a laptop or something.

My wings are not bad yet but I thought I'd mention them while the car was in and try to get things rolling.

I don't have wet carpets and the car doesn't suffer from steaming up as a bit of moisture in the cabin would cause. It's a GT TDI so there's no plugs to remove though the VW technician did suggest a small head gasket leak and obviously had no problem with sorting that should it be needed.
Not noticed and water or steam coming out of the tail pipes but there is a slightly sweet exhaust smell sometimes when the car runs from cold.

[GTI-Pirelli]

I can 99.9% state that the scuff on the steering wheel will have been done when someone was getting in or out of the car (clothing).

I have done that with my jeans a fair few times. It happens as I try to avoid wearing out the seat side bolster. Studs on the jeans catch the leather on the wheel!
They do go down with a nice warm massage. Usually at traffic lights but I don't think that contributes. I'd be surprised if they do more than some leather balm and a gentle warm with a heat gun to sort it.

Needless to say I was not in the best of moods when I first did it. Not exactly pleased when I do it now but they do go with time. 

[MikLSP]

I will have a look for who is wearing rings next time I go, first call will be the girl from the service desk who brought my car round to the front entrance. I refrained from making any cheap joke about her damaging it but maybe I should have ha 

[MJ]

Looks like they've fed the wheel through their hands then let it rest at the normal position to me.

Also you'll still have glow plugs with it being an oil burner. Nuisance or not they need to find the route of your issue.

[xjay1337]

If it's a 2.0 TDI then the slow coolant leak, if there is no external leak, is probably a porous cylinder liner.. a "common" problem. Need a new head.

All the turbos can be quite noisy , noise in itself is not a bad thing.

[MJ]

See this issue with porous heads was supposed to be dealt with by the 2006/7 mark.

The heads marked with an A number on the part I'd stamp were all no good, those with a B had a 50/50% fail rate and the Cs were meant to be bullet proof.

It's not impossible but needs proper investigation.

I'm on a B with -115k done 

[xjay1337]

Not a 50/50 fail rate. Just less likely than an A.

It's a logical issue.. If it was a head gasket the oil would be mayo-like or/and the coolant may also have oil in it. If it was heater matrix you would see water leaking around the back of the block, or possibly have wet carpets.

[MJ]

When they leak it's into the exhaust ports of the head so you see no cross coolant to oil contamination (or visa versa), just some steam and the loss of coolant. Also when the matrix splits it wets the underlay of the carpet first, so difficult to detect without stripping first.

[MikLSP]

Wasn't it the 140PS cars that suffered the porous head? Mine is a 170PS on a 56 plate. Also there is no mayo at all but that just means the water isn't reaching the oil and not necessarily that it isn't leaking to another exit route.

I haven't pulled up the carpets to check the underlay but, as I said, there is no problem with it steaming up the windows which I would expect with any meaningful amount of moisture inside.

Either way, wouldn't any such leak expect to be picked up when pressure testing? Even if the coolant was not visualised, the pressure should be lost somewhere I'd have thought.

As for the turbo, they have found enough to make them pursue a replacement so I'm more than happy to let that happen! I will ask for more details on the failings of the current turbo on my next visit when I should have more time.

[MJ]

It was more of an issue for the early heads 2003-2005. The design and manufacturing process was altered to resolve the matter but some can still slip through, you never know!

Pressure testing is sometimes a wasted task as many coolant leaks never show until the lump is mad hot. The 140s for instance only, usually dropped coolant after a long run so cold pressure tests prove un fruitful.

[DDM]

Wasn't it the 140PS cars that suffered the porous head? Mine is a 170PS on a 56 plate. Also there is no mayo at all but that just means the water isn't reaching the oil and not necessarily that it isn't leaking to another exit route.

I haven't pulled up the carpets to check the underlay but, as I said, there is no problem with it steaming up the windows which I would expect with any meaningful amount of moisture inside.

Either way, wouldn't any such leak expect to be picked up when pressure testing? Even if the coolant was not visualised, the pressure should be lost somewhere I'd have thought.

As for the turbo, they have found enough to make them pursue a replacement so I'm more than happy to let that happen! I will ask for more details on the failings of the current turbo on my next visit when I should have more time.

when i mentioned head gasket i meant water into the cylinders ect, and i wasn't sure if it was petrol or diesel, but they all have plugs, so even removing the glow plugs and looking down isn't a big or long job, only other thing worth mentioning is if it's early days like it's just started to go, and  it's using very little coolant, it might only use the coolant when up to full working temperature and when everything has slightly expanded, this will be very hard to detect as i very much doubt they've carried out a pressure test when it was hot, they've proberly just pulled it in and done it from cold, maybe suggest fitting the pressure tester ect then run the engine upto temperature, this way they won't get burn't or loose your coolant all over when they remove the expansion tank cap.

[MikLSP]

I had wondered about it being temperature dependant; and conversely whether the leak only occurs while cold and essentially seals itself as things warm up and expand.

They are looking into it again anyway so I'll be sure to suggest every possibility.

I am surprised not to see any mention of the EGR cooler as that seemed to be the most common diagnosis in search results on here.

The coolant is dropping from the max to min marks on the reservoir over about 4 weeks by the way.