118TSI Forged Piston Engine Rebuild

[rygreen93]

These 1.4 TSI's are full of surprises....just when i thought i have learnt everything there is to know about them - it comes up with something new!

Never before has an engine been messed about with so much by a manufacturer. Nearly all of it in the name of reducing emissions....or should i say reducing them just enough on the official test

The whole cat pre-heat thing only runs when the engine temp is btwn 20 and 30c - which just so happens to be the official ambient temperature range of the European test labs for emissions testing.

You would think it would do it when its colder, but nope - VW saw no need as the test lab will never be at that temperature and having the engine run like a bag of spanners every single time you cold start would cause too many complaints, so only do it under lab conditions and to hell with it in the winter - when it would have the most effect on emissions! They must have sold a lot of these cars in the winter - with their smooth cold starts....come summer the sales men must preheat them up, as its going to be tricky to sell a car that's rocking and a rolling when you first start it up.

If your supercharger runs every time on a cold start they must now be doing the cat pre-heating on every cold start, rather than only when the engine/coolant is 20c-30c. Which they can get away with as it no longer runs like a bag of spanners - instead it just screams like a banshee!

So true!!! I would actually assume that you may be right about it only being between 20-30 though I have just never paid enough attention to the ambient when I start my car. But now that you point it out I will have a look and see how it goes early on a colder morning.

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[jamaicanjetta]

Yep so started it up this morning and it's 100% the supercharger. The small belt runs and when I put my hands over the pod filter to increase the pressure you can clearly hear it pull harder to bring in the required amount of air. Must be exactly what you said blower. It's using it to heat up the cat. While the supercharger is running like that the revs are about 1100 and as soon as it shuts down it drops to 800-900. Weird that nobody else has this. Would be interesting to know someone else with a 2012 twincharger or even a newer beetle to know if it does the same.

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I have a 2012 jetta twincharger and I've never heard mine do this

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[DrTurbo]

Very interesting thread, I have bought myself a broken CAVD engine to collect parts for building a new engine, as mine has got 332000kms on it. Still pulls hard and sounds good, but time is no longer on its side.
However, I would like to mention that the cylinderwalls of these engines are coated, and this coating will be gone with a rebore, and thus taking away a freat deal of the strength and friction of the walls.

[Ryan_R]

Looks like I'll be going down the new piston route as well (not by choice). 2 cylinders have given up and apparently were shut down. Car was driveable as long as I didn't request any boost at all, which meant getting acquainted with Manual mode (paddle shift) again to keep the revs higher.

I'm assuming a cost of 3-5k to get it back to normal.

[The_Hawk]

Looks like I'll be going down the new piston route as well (not by choice).

These posts still scare me. How many km's were you up to Ryan? Any warning signs? or just BAM?!

[rygreen93]

Sorry to hear that Ryan!!!

If the pistons are cracked but haven't scratched the block then you can just buy the wossner pistons in the standard size and you won't need any boring of the block. These are cheaper than the OEM pistons and obviously much better.

It cost me $7500 for the full rebuild of the engine including cleaning everything out, boring and engineering and putting everything back together. So far no issues with the engine and it is very smooth.

I believe that you could get it for 5k. I would make sure that you replace the timing chain as it is a small cost and will be replaced by a newer version. You might as well do all the plugs etc at the same time.


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[Mk R]

Wossner Pistons for USD 634: VW Golf TFSI 1.4Ltr. - Scirocco TFSI 1.4Ltr - Forged Piston Parts

Double check the part numbers though.

I reckon you could get away with it for about 3 grand or even less if the block isn't scoured. Even if it is slightly scraped, a 1mm bore increase still gets you the 77mm Wossner.

EDIT: Some of the latest 118 TSI blow ups have been getting quotes of sub $3k for a used engine swap too FYI.

[Ryan_R]

Thanks lads

Main issues were misfires under supercharger load at first. Situation improved dramatically with new ignition coils but that was only for a couple of weeks. Suddenly misfires became much worse. I was hoping it was just spark plugs needing replacement as well. Weekend before last it surprised me how much oil it used (it would normally go between services with no top-ups required), and after topping up I did notice a little smoke the next day.


The car is with Dean Coutts who recommends replacing parts as required with new OEM. He mentioned some better parts are available for $300 less all up (not a huge discount from total price) but they take much longer to arrive. He also advises replacing timing chain, etc while working on it.

I know a couple of others who can help source and fit second hand CAVD engines (although demand seems to outweigh supply as you might expect), probably 1k cheaper than a rebuild but a temporary situation.

I've had a chat to a Dealer Principal who has suggested getting his senior tech to look at it (while nice enough on the phone I suspect it's more to satisfy their curiosity than help me out too much), but I have mentioned that I've influenced family to purchase Golf's there and would look at trading up in order to get rid of the car quicker.


I've asked Dean to stop work for now until I explore the third option (these cars seem hard to sell privately). I'm not expecting any trade in offer at all to be honest but even if I get a low ball offer I might be tempted just to see an end to this episode.
The real shame is that for months I've not found another car that appeals as much as mine. Wrong colour (black), wrong options, too many kms, visibly not looked after, etc. I'll be on the motorbike a lot more this month anyway, hopefully the weather stays nice.

[boost_junkies_tt]

Greeting Guys I'm a newbie here nice thread. You use the stock 10.1 compression ratio? Or you lowered it a bit?

[Mk R]

Greeting Guys I'm a newbie here nice thread. You use the stock 10.1 compression ratio? Or you lowered it a bit?

Hey Boost, thats a good question and it kinda brings the thread back to the build. My understanding was the Wossner pistons come in 76.5 and 77mm, 77 being needed after an overbore to clear off the scouring from the busted slug.

A 0.5mm cylinder diameter increase would be about a 1.3% displacement increase according to my terrible maths, which would suggest a slight increase in compression ratio if the only variable is a bore increase. BUT maybe the large Wossner piston has been slightly re sized (shortened) to compensate for that and keep compression the same...

Raises some more interesting questions:
- If we're going to be boring out these blocks, how much would be safe to bore out and is there an off the shelf piston that could fit?

- If we could hypothetically manage to increase displacement closer to say 1.5 litres, would the current blowers provide sufficient boost and soon enough?

- What would the implications on torque and high end output be?

- Will this car ever stop sucking money out of my life?

Also, have a chat to Rawcpoppa on here. I think he's based in Trinidad too and he's got a twincharged Jetta.