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Article: Common Issues With The 3.0T Engine | B8 S4,S5,B8.5 S4,S5,A6,A7,Q5,SQ5

Common Issues With The 3.0T Engine | B8 S4,S5,B8.5 S4,S5,A6,A7,Q5,SQ5

Common Issues With The 3.0T Engine | B8 S4,S5,B8.5 S4,S5,A6,A7,Q5,SQ5

Introduced by Audi in 2009 with the B8 S4, the 3.0T engine has become a symbol of strength and innovation in the automotive world. This engine, famous for its 333 horsepower output right out of the box, is a key player in Audi's lineup, powering vehicles from the sporty B8 S5 to the luxurious A6 and A7, and extending its prowess to the bigger Q5, SQ5, and Q7 SUVs.

Each of these models benefits from Audi's top-notch quattro all-wheel-drive system, with some also being offered in a manual transmission for those who love to take full control of their drive.

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Common Failure of the 3.0T Engine

The Audi 3.0T engine is a very reliable engine. Found on a broad range of cars from 2009-2017 Audi has learned from its mistakes and improved year over year. We will address some of the most common issues that can be found with the 3.0T engine - mainly first model years.

To answer the public, the 3.0T is a very reliable engine, makes good power and has proven to live up to expectations. Some people have reported 250k miles going strong despite some of the things that we will mention down below needing maintenance based on mileage. Here are some things for you to watch out so your 3.0T lasts as long:

Water Pump

The water pump is a known weak spot. Audi made significant improvements after 2011, but it's wise to stay alert. Problems usually come from the seals hardening or the pump itself breaking down, leading to coolant leaks. Catching this early can save you from bigger problems.

There was an update from Audi for the B8.5 S4,S5 and generally all models after 2013. All these models featured a newly designed water pump with better materials and it has proven to last longer. If you want to avoid water pump issues try to avoid 2010-2012 models.

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The thermostat can go bad on the 3.0T’s and cause big troubles. It’s an easy fix for some people to do at their garage.Most commonly the thermostat gets sticky on the inside and stuck which can cause your engine to overheat or in other cases not be able to run at optimal temperatures.

Gutted Catalytic Converters

The 3.0T comes with badly placed cats. This causes the catalytic converters to overheat, messing up the materials inside. They start to melt and clog up the works, like blocking the holes in a honeycomb. This creates a nasty back pressure on your engine. We have talked in detail about the solution to gutted cats here.

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DSG Mechatronic Faulty

All B8 S4 models have a problem with their mechatronic system. Common signs of a failing Mechatronic unit include car going in limp mode, passing gears or totally locked out gears 1,3,5,7 - which does make the driving experience pretty harsh.

The IC motor and high-pressure pump are common components for failing on the DCT DSG mechatronic unit. Pressure leaks can cause the high-pressure pump to overwork and burn out. The failure of these two components are however usually secondary issues, which are misdiagnosed as the primary suspects. 

To avoid replacement of this part you should avoid the B8 S4 or anything built from 2009-2013. For those of you who like to experiment with German performance cars, there is a solution but it’s labor intensive. If the solenoids are working well there is a good chance of a clocked filter which sits inside the mechatronic unit. Replace that and you have yourself a running DSG.

This clocked filter will block out the passage of oil and some people consider this to be the flaw in most B8 S4’s. 

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PCV Valve

The PCV valve is crucial for controlling engine pressure and keeping things running efficiently. Failure is common around 60,000-80,000 miles and can be tricky to spot, but it's vital for engine performance and emission control. This part is a little more tricky to get into as it requires removal of the supercharger and it’s not a 1 person job. 

There is no model year that doesn’t lack this issue as it's pretty common for a lot  of supercharged cars and a lot of the VW/Audi group cars having a faulty PCV valve. At a certain mileage the PCV valve will fail. It's best recommended to replace it before it breaks down to avoid any bigger damages. Common issues with a PCV valve include car misfiring a lot, not having the supercharger punch and sometimes not exceeding 4k rpm.

There are 2 ways the PCV Valve can go bad on the Audi 3.0T engines. One is on the air side, meaning you have a lot of air, so if you have a loud whistle the seal on the air side is loose or broken. This often times gives you a check engine light for a fuel-air mixture type error.

The other way the PCV Valve can go bad on Audi 3.0T is coolant mixing. If any of the holes where the oil flows has a micro crack the PCV will get filled with oil. Especially for the 2010-2012 models the PCV is made of plastic and when it deteriorates it can crack, seals will harden and it will generally fail at one point in time.

Related: What Is A Downpipe And Why Do You Need One?

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