AudiAllTheWay

Kelisko you are very knowledgeable and you have helped many Audi owners with your knowledge sharing 👍

What are the details of the design flaw mentioned in the video?

The video mentions all cylinders are low compression around ~100psi and most importantly regarding misfires cylinder 6 has a hole in the piston. What caused the hole?

kelisko

I appreciate. This is because lighter and less tough materials are used to make the pistons, the valves, the cylinder head, the piston rings, whereas the internal pressure of the engine has increased in an aim to reduce fuel consumption, squeeze more power out of the engine and limit emissions. With time and wear, these components just fail under the pressure. Trash engineering.

ElliottA6

@kelisko The modern engines from just about any manufacturer are less durable than they used to be. This is partly due to emission regulations, complexity, and increased costs. These factors along with increased service intervals make for less longevity in a modern car. I have watched you do some very complicated service work on that Audi. You deserve a lot of credit for tackling the things you have. It is unfortunate that your A7 continues to have problems. I am not a mechanic and I do not claim to know more than your mechanic. However, I consider myself somewhat knowledgeable. You may be familiar with the Scotty Kilmer Youtube channel. Some people like him and some people don't. I think he tells it like it is and often offers useful information and advice. I recall a while back he was talking about how modern engines are using floating piston rings to improve gas mileage. With less tension, these rings have a tendency to get stuck due to accumulated carbon, especially with long oil change intervals. With stuck piston rings, you have reduced compressions. I think it's interesting that all your cylinders are having the same problem, with one cylinder being more severe. One of the things Scotty Kilmer suggested is an engine oil additive from a company called ATS Chemicals to remove carbon and unstick the piston rings so there's more tension on the cylinder walls which should improve compression. Ihave no connection to this company, but I think given all the work you have done to rejuvenate your car, I would be a shame to just throw all that away. That said, you may want to try this stuff as it is not a huge investment, takes almost no time, and can't hurt anything. Here is the link if you're interested. https://www.atschemicals.com/505-pour-ins/
Good luck!

kelisko

I appreciate your suggestion but I have researched this product in the past and I am afraid it won't fix the problem unfortunately. Rebuilding is what's to do but replacing the engine would be ideal to avoid other issues and both options are way too expensive. I am getting rid of the car at lost.

KnappAttack

The 3.0t is a very robust engine. There are people pushing 500 HP on them with tunes and mods. The problem is you need octane and the proper parts to support these mods. There is no reason to hole pistons in a stock engine, other than to detonate it. With all the problems I've seen here from this dude, there's no doubt in my mind that it was ran with low octane fuel, or was tuned at one point and ran with low octane fuel. This damage just doesn't occur out of the blue for no reason. Go push your BS somewhere else.

I started to watch one of the vids and quickly went thru it here and there, and seeing its from a different unknown country and some hacks talking about the engine and vehicle, its clear to see that its in some country where they don't even know what premium fuel is or if they do the stations are more than likely selling 80 octane watered down fuel and calling it 91 octane or something.

Constant detonation or owner neglect is the only reason for this dead engine in this vehicle, not poor engineering. If run with less octane than the parameters of the tune can allow and adjust for, and timing being reduced to its maximum threshold, then the engine will eventually expire like this.

I know of what I speak as I've been building boosted, and naturally aspirated race engines for a very long time. This guys trying to blame Audi is absurd. There is absolutely no way an engine can survive detonation for any period of time on crap fuel. I come from a racing background with very thorough knowledge with the workings of an engine, I've spent more hours on an engine dyno than I care to remember, and have more World Championships rings than John Force.

I've run all my Audi at 10,000 mile oil changes and they have all gone to 200,000 miles before and the engines are in great shape. I perform oil sampling and run synthetic Mobile1 0-40 in all of them. None of them have holed pistons, cracked heads, or even blown a head gasket. I'll even run 87 octane in the stock ones with no drama whatsoever. So don't come here to warn anyone about how bad todays stuff is engineered, because todays stuff run with halfway decent care is head and shoulders over anything built in the past by a long shot. Back in the day engines would need rebuilt by 50,000 miles and cars with 100,000 miles on them were sold for scrap.

This has to be the dumbest and most idiotic post I've seen here. Big waste of time and you know nothing except the fact your engine is shot, which I'm sorry for, but there is a reason, and it's not because of todays "poor engineering", "Audi", "Mercedes", Ford, Chevrolet or any of the other OEM's. Its because its had low octane fuel for the tune being ran, and if its stock, it doesn't have NEAR enough octane to prevent detonation.

kelisko

Go through this limited list of threads and then maybe we can discuss.
2018 Audi A6 3.0T: https://www.audiworld.com/forums/a6-...n-3-0t-3021257
2017 Audi Q7 3.0T: https://www.audiworld.com/forums/q7-...-year-3024173/
2017 Audi Q7 3.0T: https://www.audiworld.com/forums/q7-...ption-2955124/
2017 Audi Q7 3.0T: https://www.audiworld.com/forums/q7-...-plus-3037451/
2018 Audi S5 3.0T: https://www.audiworld.com/forums/aud...ormal-3036961/
2017 Audi Q7 3.0T: https://www.audiworld.com/forums/3-0.../#post25824466
2018 Audi Q7 3.0T: https://www.audiworld.com/forums/q7-...tions-3056733/

KnappAttack

Just because an engine consumes oil does not make it poorly engineered. There are many reasons for oil consumption, light break in and the rings will never seat. There is always reasons, but the couple of threads I opened up you provided show nothing but some oil consumption. I didn't and wont read thru every response because many of the people on these forums know nothing about oil, break-in and don't even know how to change oil or a thing about how an engine even works, they are people who know noting about the mechanicals or how things work. They are simply drivers. 99% of the dealer mechanics are not tuners and builders even. The mechanics at these dealers are just parts replacers, even they know nothing about the how's and why's on how things actually work and why they work the way that they do. Some of them are very good mechanics, but there a big difference between mechanics and actual engineers, engine builder and tuners.

Back to break-in, proper break-in for good ring seal and max power requires bursts of wide open throttle when the engine is nw and it has good cross hatch on the cylinder walls, and I guarantee you there not many here that even know that. The reason the factory doesn't tell you that is they'd get sued if you had an accident if something happened and they had told you that. The factory runs them wide open on the dyno when they come off the assembly line to help with ring seal, but it's not enough. People think they need a easy low RPM for many miles for break-in and its absolutely not true, its actually the revers of what's needed for proper ring seal. The engine needs run hard for the best ring seal. Its the only way to prevent power robbing blowby past the rings. An engine with good ring seal has no oil consumption till they get worn way-way further down the road. Cylinder pressure is the only thing that seats the rings when the cross hatch is new. Only large throttle openings proved the pressure to push the rings into the cross hatch of the cylinder. Light throttle openings will not seat the rings. If you don't do it properly the rings will never seat well, it drinks oil and the engine will have low HP compared to an engine that was run in hard and has good ring seal. Blowby robs the engine of potential power. Most people dont have a clue about this and believe they must baby the engine when new and its absolutely one of the worst things you can do for ring seal.

Again, todays engines are WAY tougher and make far more power that anything produced in the past overall. Back in the day there was no factory turbo or supercharged engines form the factory at all. Cylinder pressures (BMEP's) are far greater now than they have ever been in the past. Old engines don't even compare or hold a candle to the new stuff. Those are just the facts.

They problems with your dead engine is detonation with the holed pistons, and cracked heads from the sounds of it. It was just run to death with improper and very low octane fuel over a period of a long time for whatever reason. It has nothing to do with poor engineering on Audis part. You cant blame Audi because the driver was stupid and ran low octane fuel in it over time. Or the owner had a tune in it and it really needed more octane than it had in the tank. Thats owner neglect plain and simple.

kelisko

Oil consumption in these engines is drastically increasing with mileage showing that the cylinders are losing compression and this happens fast. If you did really take the time to read through these threads, you would see several reports of people having these oil consumption issues ending up with a diagnosis of low compression below spec and having to either rebuild the engine or replace it. This has happened to people at even below 80,000 miles.

A lot of the things you said are true and the average consumer does not know that which means that the majority of these cars that are for sale out there are flawed. This is why I am advising people not to purchase these cars outside of warranty.

As for today's engines being tougher and more powerful, I'd say you're partly right and partly wrong. They are more powerful, yes, but are not tougher. My 2005 Audi A6 3.2 FSI quattro has outlived my 2016 Audi A7 3.0 TFSI quattro. I believe the sweet spot is between 2004 and 2008. Cars made outside of this period are just not worth it. It is sad that I came to this realization a little too late.

AudiAllTheWay

Audi and VW made great engines way before 2004. One of the most reliable long running engines Audi ever made was the late 90’s to early 2000’s 2.8L. The B5 A4 Quattro 1.8T & 2.8 put Audi on the world stage to take note. The intake injected era were all good engines 1.8T 2.7T 2.8 4.2 and even the most complicated belted B6 C5 3.0 engine was reasonably reliable. Sludging was only an issue for owners who used cheap oil and did not change oil often enough. The gov’t mandates to improve fuel economy pushed Direct Injection with “lifetime” Timing Chains forward starting around 2005. I would rather put front end in service position to change a timing belt every 100K KM’s vs pulling an engine to change chain guides and tensioners. Having said that, I am a fan of my 3.0T

kelisko

I owned a 1997 Audi A6 for 9 years and I owned my 2005 Audi A6 for 8 years then came the C7. The C5 had a great 2.4L engine but the C6's 3.2 FSI direct injected power/character/reliability wise is a much much better engine. The C7.5 3.0 TFSI has power but has no character and is obviously not reliable. From the three the C6 wins hands down.