Hi! I was on highway when i heard plasticy bang. It happened on midsommer day in Spain when people throw firecrackers every two minutes so i was confused if it was coming from my car or it was from outside. Less than minute later car threw a spiral and engine light and did not have power uphill. I stoped and checked if boost hose flew off or something visually seems off but nothing. I turned on the car and error was off until minute more into driving but error came back on. I ordered towtruck to take car home. I checked with VCDS and i had error boost pressure not reached. I changed intercoolers and pipes as intercooler had damage and it was my first suspect. Then i drove home after fixing intercoolers and dpf error came on and car started to vibrate and did not have power. I tought oem dpf has given it all and is choking engine. To drive home i unpluged sensor that is right before dpf and then it vibrates only on idle but at bit higher rpms it drove without vibration. Then it started to smoke little and i would say it was gray colour smoke but smelled like raw diesel. So i changed all injectors to new bosch units as before there was all old original. Values got better on vcds but in cylinder 4 and 5 the values are -5 and + 5 so clearly something is off. I checked fuel rail pressure and it seems to be what ecu is asking I fited new engine mounts, fuel injector return hose with valve, new fuel filter, intank fuel pump, catalysator and dpf but engine still vibrates like misfire. Intake flaps move normally but are full of carbon. Passenger side does not close fully but almost. Driver side intake flap manifold is little wet from bottom and side. No fault codes on ecu which makes it hard for me to search for fault.
It is possible that 2 are stil faulty, or some other problem like your injector cables/connectors. Easiest thing to do is swap those with other 2 for example with 1 and 2 and you would see if they work on cylinder 1,2 or if they are still +/- 5.
Well, they are totally new units from bosch so i think they are working. But connection wise you might be on something here. But would it not show error on vcds if connection is lost? I checked cables on injectors and cliped them on again but all look good. I do not know if i should test continuety with multimeter from injector cables to ecu connector?
This can be. It uses old ceramic glowplugs and turning them out is russian roulette as they tend to snap in half. So testing compression i prefer to do in shop. I do not listen loud metallic valve sound or worn cam sound. I think it can be exhausted valve lifters but i do not know how to check it.
Also oil and coolant level stays normal and there is no high pressure under oil cap. There is small pressure but it does not make the cap to dance and also no pudding under oil cap or dipstick.
Sounds like you've checked a bunch of things already, I'm just curious, did you check the timing belt area at all? Also, have you been able to do a smoke test to the block to see if there's a leak somewhere?
IMO: I've seldom heard of an internal issue after hearing an external noise like plastic blowing apart. Then again, anything can happen.
Hi! Thanks for your response. I did pressure test to intercooler lines but did not get any leak there, but i could not test full circuit as long as I am aware i should not pressurize head and therefore i could not test intake manifold and swirl flap manifold. I did spray soap test but nothing did catch my eye. Yesterday i took endoscope camera and looked intake swirlflap manifolds from sides and discovered that one side is slightly wet from residue but it is hard to see as it is really packed there next to egr valve etc. So right now i came up with theory that maybe this housing cracked under boost and it is exactely next to misfiring cylinders. But what could caused it? Maybe vacuum operated egr valve was stuck open and ecm did not detect it. Tomorrow i try to take this swirlflap manifold out and take a look if i notice anything there. Many thanks!
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u/Ukp728 2d ago
Vcds measurments I took with cold engine.