Rolf van der Toom Posted March 27, 2023 Report Share Posted March 27, 2023 Hi all, I hope that you can help me with my Lupo AUD 1.4 from 2002. It sometimes goes into some kind of emergency mode, mainly after long drives. Then a strange clapping noise comes from the exhaust. It won't accelerate anymore. After a wait it will drive normally again after shutting it down. I've thus far replaced both O2 sensors, the catalytic converter and the spark plugs. It shows error code P0441 and P0134. In t video you can hear the strange noise. Any help and suggestions are welcome! Thanks! Rolf VID-20230304-WA0014.mp4 Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 28, 2023 Report Share Posted March 28, 2023 (edited) Misfire? could be loose crank sensor or maybe ignition system. Or worse, an exhaust valve blowing...? I assume you changed the temp sensor already. First place to start usually. Edited March 28, 2023 by mk2 Quote Link to comment Share on other sites More sharing options...
Rolf van der Toom Posted March 28, 2023 Author Report Share Posted March 28, 2023 Hi Mk2, Which temp sensor do you mean? I hope it isn't the exhaust valve, because after a little wait it starts up and drives the same again. Quote Link to comment Share on other sites More sharing options...
ObjectiveAway Posted March 28, 2023 Report Share Posted March 28, 2023 No misfires? Quote Link to comment Share on other sites More sharing options...
Rolf van der Toom Posted March 28, 2023 Author Report Share Posted March 28, 2023 I'm not sure, I replaced all the sparkplugs. Shouldn't that be in the error codes? Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 28, 2023 Report Share Posted March 28, 2023 Ok, the codes tell me that too much air is getting into your engine. It might be a leak; air being sucked in via brake hose, faulty brake booster, leaking carbon canister purge valve, an inlet manifold seal having failed or even an inlet manifold crack. Many possibles. Also possible; low fuel injector pressure (fuel pump, filter, regulator...). The air:fuel mix is wrong. Are you able to use diagnostics and check all the "measuring blocks", so you can see what each sensor is measuring? Like temperature when cold and when hot, that kind of data Quote Link to comment Share on other sites More sharing options...
ObjectiveAway Posted March 28, 2023 Report Share Posted March 28, 2023 Open your hood in dark and check if there isnt any misfires, I think there will be. Also, check crankcase breather system, it is attached after throttle, if thats cloged or open you will have to repair it too. Quote Link to comment Share on other sites More sharing options...
Rolf van der Toom Posted March 29, 2023 Author Report Share Posted March 29, 2023 I've had the issue yet again, waited 30 min and it started right up again. Road service told me that it probably was a faulty injector due to the 'new' E10 petrol. How can I check which injector is the faulty one? Quote Link to comment Share on other sites More sharing options...
ObjectiveAway Posted March 29, 2023 Report Share Posted March 29, 2023 1 hour ago, Rolf van der Toom said: I've had the issue yet again, waited 30 min and it started right up again. Road service told me that it probably was a faulty injector due to the 'new' E10 petrol. How can I check which injector is the faulty one? These injectors are very good, the same injectors are used in audi 1.8turbo engine. You can remove them, add 12V directly to back of them and spray brake cleaner through them, but I think thats not injector fault. I have the same engine in my Lupo and the problem was that my crankcase breather system was both dirty and leaky. To test this you can remove air filter, remove crankcase breather pipe from throttle and block that hole. From my experience You have misfires in two cylinders (3pots should be able to roughly run but two is not enough to accelerate). Because spark plugs ignites twice in a round you hear claping from exhaust - engine failed to ignite compressed fuel (made misfire) and did ignited fuel mixture exactly before closing exhaust valve. Can you take a photo of your spark plug wires attached to ignition coil? After seeing VW OE spark plug wires there are some observations as well. Also NGK spark plugs need to be adjusted to smaller gaps for this engine, standart gap was too big and resistance made even more misfires. 1 Quote Link to comment Share on other sites More sharing options...
mk2 Posted March 29, 2023 Report Share Posted March 29, 2023 Yeah, 100% what @ObjectiveAway said 1 Quote Link to comment Share on other sites More sharing options...
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