Chasing BMN Engine Issues - PLEASE HELP

[RichTorquay]

Hi All,

After spending weeks searching forums, I am now at a complete loss. I'm trying to resolve some issues on a good friends' A3 8PA 2007, 2.0TDi 170 BMN. This is what has happened. Initial fault was "Inlet Runner Control" and lack of power, when I reset the ECU it ran fine for a while but then the IRC issue came back.

- Removed Inlet Manifold and replaced with BKD Alloy manifold (Swirl Valve Removal)

- Full clean of EGR Valve, Anti-Shudder Valve / Throttle Body

- Resealed Rocker Cover (lots of residual oil, car was producing smoke on cold startup from rear of rocker cover around turbo area

- Full service, oil change, Pipercross Panel Filter Installed. Fuel Filter replaced. This was BLACK. 

As soon as the fuel filter was replaced, the car was an absolute nightmare to start, so much so it would need 4 x 30 second fuel pump primes (VCDS) to get it able to start if left for more than a week. So, I take it out for a drive yesterday (been dealing with another Audi, long story!), and all seems ok ... until you put it under load on a Dual Carriageway. Get to 50mph, 3rd gear, 2500rpm, put demand on it and the car shakes like mad / judders. Glowplug light started flashing, Got it home and had P0299 Turbo Underboost. Should say car has always been smokey from the exhaust but was very bad.

Today, after watching a YouTube mechanic video (VW Specialist), I removed the vacuum line from the rocker cover / crankcase cover, plugged it and went back out. This time, car is so much better, whining / turbo whine (sounds like a police siren) is a bit better but still noticeable. Eureka I think! Well, back on the Dual Carriageway, yet again the issue of putting it under load makes it almost undriveable. HUGE cloud of smoke at the back this time (White/grey). Nurse it back home, scan, no fault code.

Now do the Output tests, when the "EGR Cooler Switchover Valve" screen shows "EGR cooler switch-over valve Open circuit/short circuit to ground", yet no DTC? On the output tests, the EGR valve tests make the police siren noise come back. Also, the last test screen shows "Intake flap motor Short circuit to B+", but again no DTC.

I'm absolutely stumped ................ PLEASE, PLEASE, PLEASE Help! I have Vag Can Pro, VCDS Lite, ELSAWIN and still no idea!

 

[cliffcoggin]

Richard.

You haven't told us anything about the basic condition of the engine. What is the mileage? Does it have a full service history? Have you done a compression test? Has any major work been done on the engine?

[RichTorquay]

Hi Cliff,

Sorry the stress is getting to me 😂.

The car was bought by my friend “off a friend”. Looking at the service book, it’s had yearly servicing. It’s now on 140k miles. However, I’m dubious about the history / ability of the servicing (it’s a local garage up in Dartmoor!). The sump shows signs of being resealed, there’s white sealant excess around the join. The sump was damp with oil, as was the gearbox. About a month ago, I did a Tunap Engine Flush and filled it with Castrol Magnatec C3 (Audi Spec). Air filter replaced two weeks ago, as was fuel filter which was literally black with deposits in the canister (cleaned this out also).

To rule items out, I’ve disconnected the Anti Shudder Valve electronically, the EGR electronically, the Turbo vacuum valve and the N75 solenoid. Again, all electronically, not mechanically. The car isn’t smoking, shuddering, drives lovely. Yes, there’s no Turbo boost so it has no power past 2500rpm, but the issues have gone. The horrible whine has gone as well, this usually starts around 1200-1500rpm ...

Confused.com

 

[cliffcoggin]

Richard.

After 140000 miles the engine should be OK if it has been driven normally, but if it has been thrashed over the moors by a heavy footed driver the outlook is not so good. Your description of the symptoms (smoke, juddering, lack of turbo boost,) and evidence of neglect (blocked oil & air filters and oil leaks) suggests it has been poorly maintained. Whether that means the engine is clapped out or just in need of much work I cannot say.

The fault codes can be misleading and need careful interpretation because one fault can cause problems elsewhere. For example an inlet air leak can cause EGR valve blockages, but it is the EGR fault that is reported and so owners keep cleaning the valve without realising that the real problem is a split inlet hose.

I suggest you get the engine tested by an independent Audi mechanic before you invest much more time and money in the car.