elester12

Hi Everyone,

I'm new to the Audi world but have been working on cars for sometime now. The amount of information on this forum is amazing! Now that I understand a lot of common problems with the B7 i'd love some advise.

I recently purchased a "mechanics special" 2007 2.0T quattro with 172,000 miles for sale at a local Audi dealership. The engine is misfiring and is not safe to be on the road. I've ordered the scantool but until it comes all I have is a standard OBD2 reader. The dealer stated the car needs four new coils, a new turbo charger, two engine mounts and all control arms. If I can get this car working I know the timing belt should be replaced and will do so. I've pulled the following codes below.

My question for all of you is which order should I proceed with diagnosing the misfiring? I really want to know what will be involved with repairing this car. Would hate to spend money fixing problems but end of up a major problem not allowing me to complete repairs.

P0299: Turbo Under-boost- I'm thinking I need the "D" revision diverter valve or the problem is a faulty wastegate. From what i've read I need to use the scan tool to see the charger is producing any boost. Before I can diagnose this I think the misfires have to be resolved?

P0404: Misfire

P2181: Cooling performance- Stuck Thermostat? I will use the scan tool to see if the reading from the temp sensor is off. If not then the thermostat needs to be replaced?

P0300: Random Misfire- Should I look at the cam lobe/HPFP?

A4Audi4Fun

Moving coilpacks between cylinders is the easiest thing to try. Switch the coilpacks between cylinders 1 and 4 and see what effect that has. Also make sure the harness is making a solid connection for all 4 coilpacks.

elester12

I was able to resolve the misfires by changing all the coil packs and spark plugs. The DV was the cause for the under-boost code. Thermostat was bad causing the fault for the cooling performance.

The only two remaining issue I've run into is with the fuel pressure fault code (P0089) and a loud ticking noise when the engine is started cold in 20-30F weather. When I took the HPFP off to replace the follower I noticed the follower had a hole and the HPFP piston was worn a little on the bottom by hitting the cam lobe. The lobe itself didn't look too bad. I installed the new follower and reinstalled the HPFP with a little wear on the piston. The car drives just fine and the only this code keeps coming back after 100-200 miles.

I'm holding off on repairing the remaining items such as the engine mounts and brakes until I know the cam does not have to be replaced and the ticking noise is not the chain on the rear of the engine failing. I dont have 2,000 to drop into a car that now costs less than 2k.

Any advice would be appreciated.

John535is

Replacing the chain and tensioner is not that big a deal.
I purchased the cam locking tool (which is really very basic locking device) on a auction site cheap as i knew I would only use it once. The tool locks the cams in place so it would be hard to get it wrong. It's not a must, but I looked at it as insurance risk reduction. The chain and tensioner are quite cheap with on-line sites selling good brands.
I was told by numerous mechanics that they all make that ticking noise, and/or it was a sticky valve etc, when it was just the cam chain rattling.
If you go ahead, the cam sprocket bolt has a special head so you need the right socket and its a replacement, not re-use item.
If you can replace the follower, you can do the chain & tensioner. Plenty of step by step DIY available on the net.

Same with the engine mounts, not that big a deal. I was able to manipulate the engine with a floor jack and change them without removing anything else. You can get some heavy duty ones now from 034 etc.

As for the brakes -well you need them! Again straight forward, no tricks.

elester12

Thanks for the reply. Is there any harm in waiting until spring to replace the chain and tensioner? I'll see if I can find the tool on eBay or some other site.

Also, do you think it's okay if I didn't replace the fuel pump with a little wear on the end of it from the follower wearing through?

wish I knew some Audi gurus in Virginia who could help me replace the Intake cam.

chapstick

Yes and maybe and maybe not to all your questions. Check your in box elester12.