Fastcat505

Hey guys so I’ve been fighting this problem for weeks now and it’s getting pretty frustrating. The ol ball n chain has a 2009 Audi Q5 with the 3.2l in it. I’m new to Audi’s so excuse me if I don’t use audi terminology and stuff. Anyways about two months ago she had a misfire and I replaced all coil packs and plugs with genuine Audi parts and this solved the problem well then a few weeks ago i got a p0301 code for a cylinder 1 misfire. P0302 comes up on occasions for a cylinder 2 misfire. So naturally I swapped coil packs around and the misfire didn’t follow them. I did the same with spark plugs and nothing. So then I continued to check the compression on cylinder 1 and 2 and both were at 120psi so that’s not it. After that I figured well it’s either a injector or a bad air fuel ratio. Not wanting to pull he intake manifold to test injectors I decided to smoke test the vacum system to see if I had a intake manifold leak or a broken hose somewhere to cause it to misfire and came up with nothing. I’m totally lost st this point and would really hate to tear it apart to do injectors and have that not be the problem. After this I took it to my buddies shop and used his snap on reader and it said something about a intake valve stuck open but stupidly I didn’t write down the code opps. So not sure what that meant. The car runs rough at idle but runs great when driving down the road. but again totally lost and frustrated at this point seeing we haven’t even had the car for a year. It had about 160k on it any input would be immensely appreciated thanks!

DennisMitchell

Have you tried running fuel injector cleaner (maybe SeaFoam) in the tank for a few weeks?

gk1

2009/160k Carbon buildup?
I'd agree with Dennis try a fuel injector cleaner. Redline SI-1 if you can get your hands on it. But even that may not be enough.

Fastcat505

Just put some Lucas oil injector cleaner in it hopefully that will fix my problem but I guess if that fixes it then i know it’s injectors right? such a headache 😅

Bob Petruska

This engine is prone to carbon buildup which can cause misfires. Fuel injector cleaner will not remove the carbon buildup on the valves and secondary ports. Audi can clean it up easily without removing the engine which was required in the past.

There was a carbon buildup extended warranty for these 3.2 engines. How many miles on your Q5?

Read the first post...……..

https://www.audizine.com/forum/showt...carbon-buildup

tomaszp72

Warranty was extended only on the secondary air injection system. Secondary air injection will not cause misfiring just the codes on restricted air flow. I have one of them on bank one and Audi refuses to honor extended warranty as they want codes on both banks. Car will actually not pass the DEQ with this code.

Bob Petruska

My dealer decarbons the complete engine (secondary ports, valves, intake etc.) in/out of warranty, including the extended warranty. Thus if there are misfires due to heavy carbon buildup on the valves, their cleaning procedure takes care of that.

Why not just have them clean the carbon at your expense if Audi is not going to cover it? It's quite a simple procedure and shouldn't cost too much.

tomaszp72

I may have to do that. For now I called Audi of America and opened a case with them. Will see what they say. I still have some time.

You are lucky if your dealer clears valves as well. I don't think Audi will cover it as the extended warranty clearly stats secondary air injection only.

AudiFahren11

Seafoam - THROUGH THE THROTTLE BODY!
Chevron Techron in the tank.

Will fix your problems.

tomaszp72

Techron will only help if there is problem with injectors being dirty, won't do anything for carbon buildup.