Hello everyone im new to this forum and this is my first message.
I have a 2006 Alfa Romeo 156 1.6 Twinspark (50.000km). I bought the car 2 years ago when it was around 20.000km, until the first day there is a "KNOCK" noise coming from the engine. At first that noise was very low so it was very hard to hear it but in time it is getting louder. This sound starts especially when the engine temperature reaches 70degrees and continues. The sound can be heard both in low and high rpm, also sometimes in idle. Also with this sound there's a decrease in the performance and the car is holding the rpm (in the acceleration when i shift, the rpm stays constant about 10 secs after the clutch and then decrease, its the same in the idle ) and even the engine is warm the exhaust is wet gasoline. (We changed the variator also)
There is no tuning or any modifications in the car it is compeletely stock.
No errors showed up when we connected it to the computer, everything is normal.
We checked the petrol because we think that the problem was low-octane but we were wrong. After that we checked the injectors, spark plugs and changed them but nothing happened. In additions, we changed the "knock" sensor(brandnew) but still no change. Then another "healthy" 156's Ecu tried on my car but nothing changed. Also throttle butterfly cleaned with a special spray and air flow meter(brandnew) changed but the car is still the same.
Im searching a solution but i couldnt find any
. If anyone has any idea please share.
(Sorry for my english..)