Tiguan 118TSI cracked piston

[Jad]

Well my poor little Tiguan at just 31K & 2yrs of age has been diagnosed with a cracked piston. About a week ago the engine started running rough and choppy and after finally getting it in to the dealer today they have confirmed that it has lost compression in one of the cylinders. The remedy is to install new improved pistons and replace the injectors. If the cylinder is damaged they'll replace the whole lot.

Is anyone aware of the pistons being an issue in the 118TSIs and being permanently fixed with their replacement? This is the cars final year of warranty so I'm of two minds whether to pay for a warranty extension or turn the car over for a new one.

[tigger73]

Tiguan 118TSI cracked piston

Have a read of the Golf 118TSI threads regarding issues with the twin charger engines. Unfortunately there are quite a few failures with this motor.

If it's any indication VW are not including the twin charger engine in any of the Mk7 lineup.

I would not keep it outside of warranty if I were you.


Sent from my iPhone using Tapatalk

[Ryan_R]

Aren't they in the new Beetle though?

They're higher than the normal failure rate of most new engines across the board but the majority of twinchargers have been fine.

[brad]

This is the 1.4 twincharger engine? Suggest you look at the threads for the Polo GTI & the Golff 118tsi

[tigger73]

Aren't they in the new Beetle though?

They're higher than the normal failure rate of most new engines across the board but the majority of twinchargers have been fine.

I had heard that they weren't making the 118tsi any more but it certainly is in the new beetle. It has been discontinued from the Golf 7 lineup though but maybe that's only in Australia.


Sent from my iPhone using Tapatalk

[zoomda]

Another one. That engine is a dud. If you have one and it hasn't had a problem yet it's only a matter of time. If you have the 7spd then you have double the trouble.

[Jad]

Well after having a candid chat with the service rep about the 118TSI issues he advised that the piston failure was due to the higher ambient temperature extremes in Australia vs Europe and the piston material wasn't up to the job. VW have re-engineered the pistons out of something much tougher but obviously this is no good for the existing engines without the new pistons. Apparently around summer there is an increase in twin charged 118TSI engine failures with the old version. I can't fault the quality of the service I have received though. My dealer gave me a loaner yesterday while VW has organised a more permanent one for me today, so I have to play car swapsies to get the dealer car back somehow.

[brad]

What fuel (brand / octane) do you generally run?
Have you ever run a lower octane than what you usually run & do you ever run ethanal blend fuels?

I really doubt that ambient temp is the issue. It gets pretty hot in the Arab & African nations where these are sold. Even Europe warms up a bit around The Med.

As if temps in the late 30s / early 40s are going to make a lot of difference in a combustion chamber burning at 2500 deg C. I think that the pistons are rubbish & the cooling system (oil & water) isn't up to the task. Better pistons are probably just a band-aid for the other design issues in that block.

[Jad]

Only ever run BP or Shell 98 through the car. Just passing on what the fellow said as I've never heard mention of the piston material & ambient high temps as a cause before relating to the 118TSI failures. At this stage I think we'll be turning the car over mid year as we need to move to a bigger one (7 seats) anyway and I wouldn't want to foot a second potential failure on my own dollar.

[Ryan_R]

Good to hear they're looking after you

[TSIfanboi]

he advised that the piston failure was due to the higher ambient temperature extremes in Australia vs Europe and the piston material wasn't up to the job.

My twincharger failed in December so there maybe something in that.
The following link also mentions injector spray pattern was leading to excessive deposits on the piston crown and unburnt fuel.

http://www.revotechnik.com/resources/uploads/files/TSB%201%204TSI%20Twincharger%20known%20issues%20Web.pdf

I think basically the motor was fairly tightly wound and ran a little hot.

I traded my car in even though i had years remaining on my extended warranty.
Wasn't worth the hassle of constantly being in to try different repairs that were frankly getting nowhere.

[Ryan_R]

Wouldn't Stage 1 cars be running even hotter then and be more prone to failure?

[brad]

Wouldn't Stage 1 cars be running even hotter then and be more prone to failure?

Would depend on how all the parameters are set (boost, timing, fuel map, etc). The stock car is set up with different goals (fuel economy, emissions compliance, etc) than what a stage 1 would be so it's entirely possible that the modded car might be less of a grenade than the stock unit.

Personally, I wouldn't touch the post mkV twincharger with a bargepole.

[tigger73]

Would depend on how all the parameters are set (boost, timing, fuel map, etc). The stock car is set up with different goals (fuel economy, emissions compliance, etc) than what a stage 1 would be so it's entirely possible that the modded car might be less of a grenade than the stock unit.

Personally, I wouldn't touch the post mkV twincharger with a bargepole.

I have heard (no hard evidence) that the stock software runs the engine quite lean. Gets good economy but runs hot and can result in the damage we're seeing.

The stage 1 tune may actually help... But then again I wouldn't want to have one of these engines out of warranty given it's history.


Sent from my iPhone using Tapatalk

[brad]

But then again I wouldn't want to have one of these engines out of warranty given it's history.

+1

I read a short, unofficial appraisal of the engine a while back by a respected engineer that knows VWs quite well. It was like a good idea that they simply hadn't developed properly.