B7 Audi A4 2005-2008 Common Issues and Reliability Breakdown

The B7 Audi A4 is essentially just a huge refresh of the Audi B6, from the exterior all the way to the powertrain. It is also common knowledge that these cars are able to reach 250k miles. However, with that said, there will be issues along the way.

Today, I’ll be going over all the major issues that plagued this model of the Audi A4 to better educate you about your ride or your future purchase!

Also keep in mind that not all these issues will for sure happen, they are just common among users who have had issues with their cars

Let’s get started!

(Cam Follower)

Cam follower in the high-pressure fuel pump on the 2.0Ts goes bad due to the (DLC) or diamond like coating wearing down over time and basically creating a huge hole (Show Cam Follower wear Image) and this should be changed every 30k miles. It is located right on top of the engine and it is fairly easy to replace.

You will get one or all three of these codes that could resemble a bad cam follower: P0087, P1093, P2293.

If you let the cam follower wear completely, you can expect damage to the FSI intake cam shaft and the High-pressure Fuel pump, so be sure to stay on top of it or you’ll be spending a lot of money on other repairs.

(Intake Camshaft wear)

Now, of course, this leads me to a worn or a wearing intake camshaft from most likely the bad cam follower. If you are experiencing excessive backfiring and misfires during high and low rpms and loud tapping coming from the valves, this very well could be the culprit. Now, of course driving the car with low oil and things of that nature can cause cam wear, but its most likely due to the worn Cam follower.

Replacing a camshaft is not the easiest thing to do and cams can be fairly expensive, so keep that in mind.

(High-Pressure Fuel Pump failure)

The high-pressure fuel pump can fail. Usually these fail from a bad cam follower as well. You will most likely experience stalling and ultimately no starts. Once again, you will receive the same codes as mentioned before. The pump can be pretty expensive, but it is easy to replace, BUT that is why you should keep a close eye on the cam follower.

(Code P0299)

If you are getting the code P0299, it could be correlated to two things. First, the diverter valve, which basically helps release pressure from the intake system when you release the throttle. The OEM one usually cracks over time and Audi has made a DV+ or an updated one to fix the cracking. If you are still getting a P0299 code, then that most likely that means you have a bad wastegate. Both are located underneath the hood. Basically, this video shows an example of what i am talking about: https://youtu.be/Cl4AuMc8zfg?t=34 the arm connecting the wastegate to the turbo has a lot of play. You can use a clip that Audi stocks to reduce the play from the lever, however, the flat piece of the arm may also have play, which could also leak. Here is the other location: https://youtu.be/SSnjzUgOXRA . If you do not have that leak, then replacing the wastegate actuator itself is the way to go. So, that is probably why you don’t have boost.

(Misfire/Hard cold start)

Misfires and hard starts! this could be related to coils going bad, low fuel pressure and excessive cam wear. All of which I have talked about. And, all these issues are only on the 2L t motor, so far. But, if you are having this issue and you do not have the 2lT, check the coils and sparkplugs.

(Low oil pressure)

Low oil pressure in the 1.8l and 2.0L. This is most likely due to a clogged oil pick up tube, which can be replaced by removing the oil pan. And just like the cam follower, the pickup tube is inexpensive. If you are experiencing low oil pressure, do not drive the car to prevent any further damage. The pickup tube can be clogged by several things, like the oil dipstick tube crumbling over time, The PCV system, lower crankcase breather elbow can crack, and all of this can block the pickup with plastics.

(Timing Chain tensioner)

if you are experiencing rattling noises from the back of the engine, then most likely your timing chain tensioner is failing. The 3.2L, 2.7L and the 3.0L V6s engines have a timing chain in the B7 model. The B8, however, all having timing chains besides the 2.0L TDI I4. Sorry for the confusion everyone!! The stretched chain was still an issue throughout the two models.

This is somewhat common. On the 1.8l model, you can access the tensioned by removing the valve cover and a cam, then replace it and the 2.0l model you’ll need to basically you have to take apart the back of the engine, which is somewhat an extensive job to do. Here is a video of the process: https://youtu.be/Vqo1fwWaR-s?t=960

Be sure to replace the part with the updated part from Audi

(PCV Issues)

If you are getting engine surges, oil sludge, MAF codes, 02 sensor codes, increased internal engine pressure and leaking oil, you may have a bad PCV Valve that is stuck closed! Or engine misfires, lean air-fuel mixture, increased oil consumption, hard engine start, rough idle, black smoke, or fouled plugs, it may be stuck open! You may just get a few of these symptoms, but over time, they may start piling up on top of each other. Replacing the PCV should fix that issue and it is not all that hard of a job.

(NO AC)

If you are experiencing no ac in your car, it could be a few things. first to check is the high-pressure switch, then the actuator, and finally the compressor, which is the costliest. All of which could go out and cause you to have no AC in your car. And there are videos out to help you check all of that, it is just too much to explain here.

Conclusion

Overall, these cars are pretty reliable machines. The main issues lay within the 2.0T Engines due to their cam follower issues. So, keep that in mind. Even with those issues, they can easily be avoided with proper maintenance. Also, if you see an A4 2.0T for a too good to be true kind of price, it may be just that. Do your research and check what needs to be checked so you do not get screwed over.

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If you do not want to read all of this, watch this instead: