Hi all my first post and a bit of a saga. The story so far.......

I filled with fuel at Tescos on a Friday and the car failed to start the next morning, cranking well, engine completely lifeless. No fault codes displayed. Had the car towed to a mechanic I have used for servicing. He bled the diesel system and managed to start it again. He said that there was air in the system but no cause was identified. He got it started and I collected it. Drove to Bristol the next day and back, 100 miles, stopped and started fine say about 5 times, ran well. Left overnight.

Failed to start on the next day same symptoms as before. Had the mechanic come to mine, who got it started again, and drove it back to his workshop. The mechanic did some tests on the tandem pump and the pressure was below spec at 1.5 bar at 1600 rpm, forgive me I can't remember the exact figure, and ok at 4000 rpm. He replaced the tandem pump, started the car regularly over the next few days all OK. He thought that there might be a problem with oil leaking into the diesel through this pump. I drove the car back and left it overnight. It failed to start easily the next day again but it sounded different so I persisted and after about 10 second it started. So i took it back to the mechanic again. He checked the fuel system and thought that the fuel was not right and there was contamination in the tank, tank pumpp and filter housing, see photos. So he drained and cleaned the tank, new tank pump, fresh diesel, new fuel filter, timed the injectors. Started the car. Left it for 48 hours and it started fien again,so I collected it. Drove to Bristol, 50m, all OK, then back east on M4. Car power failed completely at 70 mph after about 6m, no mechanical bad noises. Pulled over to hard shoulder. Tried to start but rough and lumpy. Called RAC and waited. 1 1/2 hours later he arrived and managed to start the car after cranking for 10 secs, so we drove to Leigh Delamere services. Ran daignostics and came up with the attached fault codes. The cruise control ahs not bee working for many months. Fault codes: 11804; 16685; 01135; 00895. Restarted car and proceded for about 6 miles when the car failed again with RAC man following. There was a brief period of lack of power ie hestiation before failure. Towed the car back to the mechanics workshop. I gave him the fault codes and one relates to injector 1 misfiring. I though that this might simply be due to the roughness when trying to restart after the failures. He then said that I might have worn through a bucket under the cam, which was a problem he had with a golf mk4. The engine is mechanically very quiet. Oil level is not fluctuating and is not too low. We're starting to look at serious money here and I need some help from the forum. Personally, I might be in denial, but it looks like possibly bad fuel and fuel starvation. What do you think?

Hi Guys,

this seems to be a common fault with BKD engines. Somebody must know the answer!

Hi,

Its not particularly common with BKD engines but not completely unheard of either. The question is did the contamination come from the fuel itself, or from the failing tandem pump? A leaking tandem pump can start mixing oil with the diesel in small quantities, but over time can add up to quite a bit of oil in the fuel system. Failing injector seals are another possibility on a PD engine.

It also could be worth checking if the in-tank electric fuel pump is getting power consistently. If this is cutting out intermittently it may give the symptoms you are experiencing.

Thanks Nick for your reply.

The tandem fuel pump, fuel filter and tank lift pump has been replaced, tank cleaned and fresh diesel used. It is an interesting idea that the supply to the tank pump itself might be internittent. I believe that there is a relay by the battery, which is fairly cheap to replace. The mechanic did say that before he replace it it was pumping hesitantly and he put this down to the crud in the fuel blocking the pump filter, but it could be the power supply! I've also found someone who had the injector fault due to a poor connection on vacuum side of the tandem pump. I'm going to try all the simple stuff first. There is no evidence of wear on the camshaft. Another possibility is that the retiming of the injectors may not be quite right and this can lead to warm running problems. I don't think at the moment that it's the dreaded injector problem. Can anybody definitive state that Octy BKD engines, mine's 2006 reg, have only Bosch PD injectors?

We may go down the injector seal route later.

Firstly, yes BKD engines do definitely have Bosch solenoid injectors and aren't affected by the injector failure problem that PD 170 engine can suffer from. Also a single faulty injector on the Bosch system doesn't tend to cut the engine out completely like it would on a Siemens piezo setup. It may be the cause of slightly lumpy running, but shouldn't cause the engine to totally die at 70 mph like yours has been doing.

Camshaft wear does seem less common on these 2.0 twin cam PD engines than it did on some of the earlier single cam 1.9 PDs, but perhaps still can't be totally ruled out. Yet another possibility is the injector wiring loom under the cam cover, but I think that tends to flag up more specific fault codes when it starts to fail.

Incidentally I have a strange problem on mine where, say every 9-12 months, out of the blue it will just crank and crank on the starter showing no inclination to start. If I persist eventually after about 5 attempts it will splutter, start and then run fine for another 10,000 miles or so, til it feels like doing it again! Two main dealers have looked and can find nothing wrong, VCDS scans show nothing amiss, and looking at the live data in VCDS shows injector values etc all look fine. I've come to the conclusion on mine that it could be something silly like the fuel pump relay intermittently sticking, or the crankshaft sensor starting to pack up, but I've not been able to pin it down yet.

I've asked the mechanic to replace the fuel pump relay to eliminate that possibility if it's not expensive, monitor the injectors again and run the engine for a while to see if he can replicate the fault. Your last statement is interesting as that's about where I was once the new tandem fuel pump was installed. Hope your problem stays very infrequent!

I'm also going to get a second oppinion from the local skoda dealers.