A4 B8 1.8 TFSI Engine Rebuild Time - Excessive Oil Consumption

[ozynigma]

I have a 2009 A4 1.8 with CVT that is now using 1.4 litres of oil per 1000km (as measured by Audi) at 85,000km. So its now three years out of warranty and suffered a major (actually progressive) failure of the piston rings. I know this is a common problem with 2.0TFSI engines.

Tomorrow I will be calling Audi Australia back to try and get the best deal I can for an out of warranty fix. I am inclined to remove and replace and rebuild the engine myself if they will give me the parts free or subsidised. I don't really want to be paying most or all of the dealer labour costs for that job plus I want it done right the first time.

I have rebuilt a couple of engines before so I know basically what I am up for. What I am looking for is any tips or tricks that I should be aware of with these motors. Also a link to any how to's or technical manuals would be great. I haven't searched for these yet.

My research indicates that the later design rings come with different pistons and a different wrist pin diameter and hence different connecting rods. So the minimum job is a drop in pistons and rods swap with the head and sump off in the car.

My thoughts so far are;

1) at 85,000km I would not be keen on just honing the cylinders and hoping they are in spec for stock sized pistons. i would prefer to go the extra mile and bore out to 0.5mm oversize and completely re establish the new bore to ring interface.

2) similarly I would be changing out main bearings (as well as big end bearings of course), front and rear engine seals and the timing chain.

3) I would be getting all the valves reseated which will of course get the intake valves cleaned as well.

What does everyone think? Should I do more or less work while the engine is disassembled? Have I missed anything major? Are there any special tools I am going to need?

Also does anyone know if the 1.8 and 2.0 pistons are identical? I haven't asked Audi for part numbers yet. They are the same bore, only the stroke is increased on the 2.0 motor. Mahle does aftermarket for the 2.0. I haven't been able to find any aftermarket specifically for the 1.8.

[Umai Naa!!]

Fair bit of specialist tooling involved with the assembly and setup of these motors.

I'd be searching for a complete motor.

[Notso Swift]

The problem is the rings were not run in hard, (not to uncommon at all, actually, it is probably normal!)
there is no need to replace the bearings, maybe the big ends, only because you have to take them off, but changing the mains will more likely cause problems

( and now the reason why, in the after market you typically buy bearings 0.000 or machine to +010/020/030" at the factory they have "0.000" then they will measure them to +/-0.00001 -an extra decimal- and usually two steps up and two steps down, so 5 options. You simply cannot replicate that accuracy)

[ozynigma]

Fair bit of specialist tooling involved with the assembly and setup of these motors.

I'd be searching for a complete motor.

Thanks. I am trying to get specifics on any tooling required. I just rebuilt my Mazda CX-7 DISI motor with an unkeyed crank and VVT on the inlet so I don't mind a challenge.

I would probably trade the car at a loss rather than put another motor in as its another unknown quantity and I expect it would be well over $5k for a motor. Maybe I could find a Skoda donor. I haven't researched that yet.

[ozynigma]

The problem is the rings were not run in hard, (not to uncommon at all, actually, it is probably normal!)
there is no need to replace the bearings, maybe the big ends, only because you have to take them off, but changing the mains will more likely cause problems

Thanks for the feedback.

Yes I was aware of the running in issue. I understand it was probably worse with the CVT models. If they are babied in Eco mode they will sit under near constant load at near constant revs. We bought the car 4 months old as the second owners. It had about 6,000kms on it. Of course I never babied it and rarely used Eco mode.

Thanks for the suggestion on the main bearings and the reasoning.

I am trying to make sure I do all the beneficial jobs if the motor gets pulled down.