LCV

2010 Audi A4 Quattro
2.0T TFSI (B8 - CAEB)
153K Miles

I've an issue with my A4 (with 153K miles) hoping someone from here maybe has had similar issues with. About a year ago the valves were replaced and at that time though it’d be a good idea to replace the fuel injectors too because of the milage and carbon issues. Ordered the ones that came as a kit from ECS Tunning. Fast forward to last week and I started getting faint gas smell and got a very apparent ticking noise.

I figured I’d get the original OEM injectors professionally cleaned and pressure checked to reinstall them. Never got chance to so as the car started running rough as I was at a stop light…pulled over as quick as I could parked it and shut it off. Tried to restart and it wouldn’t restart and the CEL came on. Checked the DTC and had three of them, (P103A, P0301, P0304), all misfire codes.

So, at a minimum thought I’d take the plugs and coils out and look them over.
- Cylinders #1 & #4 slightly oily with gas smell and slight carbon build up
- Cylinders #2 & #3 seemed normal enough to me.

I did a compression test just to see what I was getting for compression. Did #1 cylinder and got a strong gas smell and only got to 90 PSI. Removed the gauge and turned the engine over and fuel didn’t just make a slight puff…it was like a damned fuel jacuzzi bubbling up out of it. I stopped the testing took off the intake manifold and all the injectors. Didn’t really see anything notably wrong with injectors 1-3; however, #4 injector had carbon build up all over the exterior of it. The white Teflon seal at the very tip was gone along with the black spacer…think they both melted off? Did a preliminary check of the intake valves: All had varying degrees of carbon build up.

The obvious thing to do in my mind is at a minimum replace the injectors with the original OEM ones. Along with that new oil filter, oil and spark plugs.
My question from here...is there anything else I should be checking/replacing that I haven’t already mentioned?
I haven't been around these engines very long...how concerned about this should I be...Is my motor totally screwed?

Would appreciate knowledge from anyone that has dealt with this sort of thing before.
Thanks a head of time for your time!

AudiAllTheWay

One suggestion is disconnect power to the fuel injectors while doing a compression test. It is one of the two multi pin connectors under the front face of the intake near the air box.

Vin_16

Hi LCV, I hope this helps. The issues you've described, especially the noticeable fuel leakage and misfires, suggest multiple potential problems in your Audi A4. Here are a few steps and considerations:

1. Injectors: As you've noted, replacing the aftermarket injectors with original OEM ones would be a good step. Ensure proper seating, seals, and connections of the injectors to prevent fuel leaks.
   
2. Valve Carbon Buildup: The carbon buildup on the intake valves could be impacting performance. Consider performing an intake valve cleaning, either by walnut blasting or using specialized cleaners, to remove carbon deposits.
   
3. Compression Test: Conduct a complete compression test on all cylinders to determine if the low compression on Cylinder #1 is consistent across the engine. Low compression might indicate internal engine issues.
   
4. Spark Plugs and Coils: Replace the spark plugs and coils, ensuring they are in good condition to support combustion in each cylinder properly.
   
5. Check PCV System: A malfunctioning Positive Crankcase Ventilation (PCV) system can cause excessive pressure in the crankcase, leading to oil leaks or issues with combustion. Inspect and test the PCV system components.
   
6. Professional Diagnostic Scan: Use a comprehensive diagnostic scanner to retrieve all fault codes and perform a complete system scan. This will help identify any other potential issues or hidden codes in the engine control system that could be contributing to the problems.
   
7. Professional Inspection: Consider seeking help from an experienced Audi technician or a reputable mechanic who specializes in Audi vehicles. Their expertise and experience could provide valuable insights into the root cause of the issues.
   

Concerning the extent of damage to the engine, it's hard to ascertain without a thorough inspection. However, taking the above steps should help you address some potential causes of your engine issues. If you're unsure about performing these tasks yourself, seeking professional assistance is advisable to avoid further damage and ensure proper resolution of the problems.