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vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - zango


My golf has just suffered the piston damage and loss of compression problem that has been reported on the internet. Mine was 19 months old and 34K miles when I noticed the symptoms. I got it straight into the dealer so did not get the bore damage that others have suffered.

This leads to my dilema, because unlike the others I did not get a new engine. First thing to say is that the dealership were great and supplied me a loan car throughout. However, they were following the VW fault diagnosis proceedure (which is fair enough as VW were paying) but did take rather a long time to fix the problem as they changed the cylinder head first.

"You don't want to believe what you read on the internet Sir" ..........

The second thing to say is that the vehicle is a lease car so will go back at the end of 36 months with approx 60K miles.

The fix was to replace number 2 piston and rings. I regard this as a sub-standard repair. Mixing new and old pistons is just not done in my book. How is it going to bed in properly? and what about the temperature differentials in the engine?

I appreciate that VW have repaired the vehicle so have fulfilled the conditions of the warranty.

Can i reject the car, either via VW or the lease company or do I have to run it until it either goes wrong again, or goes back?

It seems a bit unafir on the next owner that they will potentially get a timebomb. I certainly won't be buying the car after the lease ends which is what I was considering.


vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - Mike H

You need to contact an expert to get a written opinion of whether the repair is considered to be nechanically satisfactory. Are you a member of a motoring organisation? Have you contacted the lease company?

vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - zango

Hi Mike,

Thanks for the advice.

I was going to wait until I got a copy of the repair invoice......once I get the car back!

I will then get onto the lease company and the AA for advice.

If the car has poor performance or high oil consumption in the meantime then I will reject it immediately. What is slightly worrying is that there is no mention of any VW modification for the problem. So potentially it will recur at a later date (when the car is out of warranty).

Cheers Peter

vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - davmal

Replacing pistons and piston rings per cylinder, rather than as a set is not an unsound, or uncommon repair.

Without seeing the damage it would be impossible for anyone to comment on the appropriateness of this repair.

The bedding in question is a bit of an anachronism with modern manufacturing techniques and QA. If the engine is pot tested, and passes, the liner dimensionally checked and without serious damage and the crankcase is not over pressurised when running, then the rings, piston and liner are doing their jobs.

vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - 659FBE
I would regard the replacing of a single piston to be bad practice, on the grounds of matching.

When an engine is built, pistons are selected according to bore size and also matched as sets for weight. The replacement of a single piston renders this process impossible to achieve and may result in an engine failing to meet new build specifications for balance and long term oil consumption. These parameters cannot readily be tested in-situ and in short term use.

I would regard this repair proposal as a potential failure by VAG to return a defective engine to its new build standard. Press for engine replacement.

vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - davmal

"When an engine is built, pistons are selected according to bore size and also matched as sets for weight. "

This is not specified on the engines that we rebuild. A piston fails, a new piston comes out of the box and gets fitted, without weighing the others.

Using OEM parts I would expect the pistons, conrods and cranks to have been manufactured to a fitting tolerance.

vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - LucyBC

The car is 19 months old, broke down and was fixed at the manufacturer's expense.

It is a lease car and goes back at the end of the contract.

I don't see what loss you have suffered and you certainly do not have any grounds to reject it.

vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - zango

Perfectly correct - provided the repaired car does not perform worse than a standard car (i.e. unrepaired) during the remainder of the lease then I have lost nothing.

However, I don't think the same is true for the lease company if they keep it, or the new owner they sell it on, if the longevity has been any way impaired.

With regard to the repair itself. My understanding is that new engines don't need running in these days because of improved manufacturing tolerance and the fact that they are bench run before being installed.

This would clearly not be the case when you put a new piston and rings into a used engine. However, there is nothing to say that the repaired engine won't be perfectly fine.


vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - zango

Hi Davmal,

What exactly is "pot testing"?

The reason I ask, is at the risk of appearing old I don't think that main dealers have any experience of rebuilding engines these days. Their business is all based around servicing and plugging the fault code reader into the OBD port. They have priced themselves out of the market for older cars...especially those out of warranty.

The ones who have my car, having diagnosed low compression (presumably by a compression test) but it could have been via OBD (crankshaft acceleration) took the head off for a visual inspection. They did not take the simple step of filling up the bores with petrol or light oil and comparing how long a good and bad cylinder take to drain down.

They went straight on to change the head believing it to be porous!


vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - injection doc
when working in dealerships I have replaced many single pistons, and as long as they have been standard , never a problem.
I have always used a glaze buster first. If the bore was in bad shape then it would normally be sleeved & bored spo a standard piston would be fitted to match the rest.
never had a failure
I would worry at all!
Having a total replacement engine has its owns risks, at least yours is tried and tested.
I think you just lost some faith in the useless diagnostics by the garage first!
vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - davmal
Pot testing is just a compression test, but static. Inject compressed air into the cylinder through the injector/plug hole (low pressure) and monitor the capability of holding the charge. If it leaks away (slowly but not too slowly), add enough engine oil to the cylinder to seal around the rings (cold oil is quite viscous). If the pressure stays now, the chances are it is the bore or rings at fault if it still leaks, could be looking at head problems. Must ensure that the valves are closed ie lift rocker gear/followers. Don't forget to syphon out the oil before spinning it over.
Porous aluminium castings aren't uncommon, and they can develop porosity through age and use.
Whilst the OBD facility is an awesome progression, it can shift a technicians brain firmly into neutral and lead to a somewhat dogmatic approach to diagnosis, saying that, there is only so much you can summise before you have to get your hands dirty:(
vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - injection doc

We called it " Cylinder leak testing" very effective & very good for diagnostics.

I would use scope analysis rather than OBD.

vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - itavaltalainen

Hey, out of interest - What happened to your case? About the damage itself: From what I know most engine failures in 1.4 TSIs are from a batch of engines built in spring 2009 (late March, April, early May). If VW have not given you a new engine already, just keep driving it with their long-life oil and with as many cold starts and short trips as possible, it will blow again....

Edited by itavaltalainen on 28/01/2011 at 09:18

vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - zango


What a timely post!

I got the car back with a new number 2 piston and cylinder head. It was pronounced fit after a compression test and road test. To be honest it was fine. A smooth idle and lack of hesitation were the most obvious differences.

However, the mpg never quite returned to normal. Last week, 1300 miles after the rebuild it started hesitating again when at low rpm, especiallly when in high gear. It is a DSG so gets into high gear quickly.

I have checked the oil and it is black and smells of combustion products. I also ran the engine with the filler cap removed and there is noticeable back pressure but no obvious smoke/gas.

It is due a service in 1100 miles (38K ish total), so that is when I will report the fault assuming it lasts that long.

I presume that you have some inside knowledge. Mine is indeed at early 2009 car. Delivered 28th April so built January onwards. Many thanks, you have put my mind at rest.

Cheers Pete

vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - LucyBC
you have put my mind at rest.

What really? It is a post in a forum with no knowledge known or assumed.

vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - zango

Lucy - knowledgeable people post on this forum.

If they didn't there would be no point in having it. The existance of a problem with early versions of the VW 1.4 engine has been widely reported. It is only through the exchange of information that the consumer stands a chance against the cartel of manufacturers and dealers.

I am happy because I have an explanation that makes sense - that's all.

Best wishe


vw golf mk6 gt 1.4 tsi 160 engine problem - VW warranty repair - itavaltalainen
Hi Pete,

sorry to disapoint, but have no inside knowledge per se.
But there are lots of forums in German, which is where I got most of that info, as I was thinking to get a mk6 TSI to replace my aging mk3. At this time well over two thirds of reported blown engines there where manufactured in spring 2009, with either piston 1 or 4 blown.
Cause, according to dealers unofficial info, seems to be the injectors, they build up deposits which change the fuel spray characteristics and wash off engine oil from the cylinders causing it to loose compression. Second thing that has been more or less confirmed to happen are broken pistons due to heat problems, this is however more speculation in different forums rather than confirmed dealer info.

They re-built the engine but have not changed the oil?! Don't think they would be this stupid, but hey you never know.
Would be surprised if you didn't feel any air movement when running the engine with the filler car removed, the crankcase as well as the valvetrain are connected to the air intake as pressure would build up in the otherwise (movement of pistons, shafts, blow-by...).

Watch how it behaves and well, hope for it to break down again, so you and following owners don't have to deal with your current engine when it's out of warranty.

Regards Michael

vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - Avant

The way to put your mind at rest is not to worry about the next owner. It's kind of you to be concerned, but in reality when you hand the car back to the leasing company it will be passed through several different people before landing on a forecourt or (more likely) an auction.

There's nothing you can do, so relax.

vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - zango

Just got the car back today after VW fitted a complete new engine FOC.

Not just a short one either, the entire thing, so including spark plugs, timing belt and oil filter. Additionally the air-con was re- gassed as it needed to be dismantled in order to get the engine out.

The remaining (non engine) items on the 2nd (major) service only cost £90.

So apart from the inconvenience of the recovery (2nd failure) and the fact that the car was off the road for 40 days in total, a satisfactory result in the end.

Cheers PM

vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - PCDC

Hi, I found this thread very interesting. I have just, last week, had a Cylinder 1 failure on a 2009 Golf GT 1.4 TSI 160 which has done 13000 miles! Initial indications of Emission problems were intermittent and no fault found, other than evidence of a 'misfire' on a servicing last month. However, problem re-appeared at low revs and finally fault lights convinced the dealer that there was a problem.

The dealer, from whom I bought the car and who serviced it last year and just recently, took quite a while to diagnose the fault. The engine strip down showed a failure in the 'bottom' end with someting apparently failing in the piston connection area and falling off. Very surprised the car ran as well as it did!

However, now a complete new engine is being fitted - apparently one can't get the separate 'top' or 'bottom'. I'm pleased about the complete unit because there will now be no problems 'mixing and matching'. I have read what others have said in this thread but I'm afraid I'm old fashioned about fitting anything other than a complete unit in case there are problems in the future - I aim to keep the car for a number of years.


vw golf mk6 gt 1.4 tsi 160 - VW warranty repair - zango

Hi Zango here,

My update is that the new engine is fine after about 8K miles. Better mpg than the previous one.

However, I have had another two faults with the car.

1. A throttle actuator flap motor failed.

I think this switches between the supercharger and the turbo charger. This limited operation to 3000 rpm before loss of power.

2. Misfiring and going into limp mode. Caused by two faulty spark plugs. These were changed under warranty because the service record show new plugs with new engine. However, it looks like it was still on the old plugs, so I am going to have to buy a couple a put them in myself.

So that is a total now of 43.5 days off the road.

"if only everything in life was as reliable as a golf" - NOT


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