A7 3.0T engine rebuild and cat's

[hektor]

Hi there!

My 3.0 TFSi engine will be rebuilt soon(all new pistons, block will be worked on also, A LOT of new parts in the engine etc).
Like I understand the first 500-1000km will be the break in period, after that the oil change when the pistons have worked in with cylinders.
Anything else I should know about the break in period?

I bought the car some time ago with a custom exhaust and since the MOT needed(before I was the owner) catalytic converters the last owner put cheap ass universal catalytic converters. Since then I changed them to better EURO5 ones but those wont last long like I understand. What should I do, replace them with the original or get something aftermarket? I wouldn't want to replace the whole exhaust system.

Thanks!

[M1k3ee]

Is your car tuned? If so, I would put the catalytic converters under the car, not where the cats are located originally just after the exhaust manifold. I have GESI 50225 catalytic converters in the downpipes under the car and they work great, no smell.

[hektor]

Is your car tuned? If so, I would put the catalytic converters under the car, not where the cats are located originally just after the exhaust manifold. I have GESI 50225 catalytic converters in the downpipes under the car and they work great, no smell.

No tune, stock rightnow. Might be doing stage 1 later but not at the moment. So you recommend those GESI 50225 cat's? My current EURO5 ones are still cheaper, like 250$ per cat. Also should put them further away from the original position(since there is much heat there I guess?)

[dalmation53]

question to why your engine is getting a full rebuild?

[hektor]

question to why your engine is getting a full rebuild?

High mileage 270k km/~170k miles, drank oil(1l per 1000km) and failed the MOT because of high CO and CH. Pistons were oili and really worn, few cylinders had some smaller problems also..cylinders will be honed but it will be fine afterwards.
Getting a new(used) engine is almost as expensive(and these engines are hard to find) and there are no guarantees that it's in good shape, so I chose full rebuild. Rest of the car is in great shape.

[Valpo A7]

Have you checked compression on each cylinder? These motors can typically last longer that where you are at. Heavy oil consumption is typically means you need a new PCV.

My 2012 is at 213,000 miles and still going strong.


Sent from my iPhone using Audizine Forum

[fastboatster]

Have you checked compression on each cylinder? These motors can typically last longer that where you are at. Heavy oil consumption is typically means you need a new PCV.

My 2012 is at 213,000 miles and still going strong.


Sent from my iPhone using Audizine Forum

Umm, yeah, and you had to replace all the timing chains and clearly you have an exclusively highway mileage. Op has 170kmiles which is plenty high, I saw very few 3.0Ts with even this many miles and heard about a few which started to drink the oil after 100kmiles and no pcv change would help. OPs mileage probably includes more street driving as well. I don’t think I’d expect a 3.0T to last a long time after 170kmiles anyway unless it’s all hwy miles

[Valpo A7]

I cannot speak for how the original owner drove my car but yes once I owned it I did mostly highway miles. When I was getting parts together to do my chains I was told by Audi techs as well as ECS and FCPEuro that chain replacement was rare on the 3.0 platform. There is a guy on Audiworld that has over 345,000 miles with his original chains still in the car. I looked last night on cars.com and a few Audis with over my mileage being offered for sale and quite a bit with over 170k miles.

Going over 200,000 miles on an engine with normal maintenance should be normal now with current engine building technology.

I still say to the OP check compression and check the health of the PCV system as step 1 before pulling the engine for a rebuild. Typically but not always a new PCV fixes a lot of the oil consumption on the 3.0 platform.


Sent from my iPhone using Audizine Forum

[hektor]

I was hoping it will be PCV but i did the PCV check also(and it was replaced few years ago by previous owner).
Before I got the car it was in the Netherlands(more highway drives, long range) and also in Estonia with different owners.

The engine is already taken apart and the block sent overseas to Finland where its getting honed. New pistons 3 OE and 3 Mahle ones.
Since the chain job was done 35k km ago and it's fine rightnow they won't do that job(would be more expensive also). Only 1 tensioner that is getting changed "just in case" since the engine is already off and taken apart.
I only have to wait until the job is done.
Then it should be 1000km to break the engine in, should the first oil change done in 500 or 1000 km? Or both 500 and 1000km?

Oh yeah, the car itself is 2011 A7 with S-tronic/DSG 7-speed 3.0 TFSI 220kw. Gearbox is working great and has been serviced well.

Any more ideas about catalytic converters? Since my universal euro5 cats are "so-so" rightnow, should work okay for 1-2 years atleast. Not gonna put a whole new exhaust system since the exhaust itself sounds great.
The option would be stock cats also but should I(new OE ones were quoted like 2200 EUR + work, can get used ones much-much cheaper)? Or the ones that M1k3ee recommended...or something else?

[Valpo A7]

Stock cats are good, just not cheap. Magnas look good but I have no info on their quality. You could also go test pipes and then relocate the cats into the flex pipe.

As for engine break in, ask your builder. Everyone seems to have a different idea on it. Audi sets the new car oil change at 5,000 miles with a 10k interval on the rest. Other manufactures have yet different ideas as well. Had a 1995 Mustang GT that did not short cycle the oil first oil change but rather to baby the motor and no cruise for the first 1,000 or so miles until you do any pulls on the motor.


Sent from my iPhone using Audizine Forum

[hektor]

A littel update, engine is rebuilt and works great. Went to MOT but failed the emissions because of high CH. I guess the cat's are full of burnt oil(since I was leaking a lot of oil before), that what the MOT employee said...he seemed like a nice guy tbh. The cat's are about 6 months old.
Do you think washing the cat's will help to get the CH to normal? Gonna go to a exhaust shop tomorrow and I hope I could pass the MOT without spending big again. Best bet would be washing the cat's and passing. Or maybe new universal cat's. If I pass the emission test then I have time to think of getting OEM cat's or something better...rightnow need to get the car road legal again.

What is your take on it? Found out that my car has deleted o2 sensors also because of the custom exhaust built(and written out so no errors).

[Blackmagic88]

Is it even worth it only getting upgraded performance cats ?

[hektor]

Just got back from MOT and pushed through.... had to drive the car hard to clean the burnt oil in cats so they start working.

Now I just have to dyno the car to see what ecu tune is done, since I don't know anything about it and I don't want to risk the unknown tune.