So my wife's 2004 Passat TDI has a new, possibly very bad noise.
It sounds like a "thudding", that is loudest near the air filter. I opened up the airbox, and it is definitely pretty loud coming out of the air intake pipe. Sounds like you are hearing the engine firing. The car also seems very underpowered, and is blowing more black smoke than usual.
My thoughts so far are head gasket, intake valve stuck open, or possibly a faulty injector. Anyone ever experienced this before?
After doing some research online it seemed like the EGR could be at fault. I took the intake all apart and cleaned a ton of carbon out of there. Reassembled with new gaskets, but the issue is still there. I really thought that was going to fix it
This is what the EGR valve looked like
This is the carbon that was pulled out of the intake
This is what the intake ports looked like
It sounds like a "thudding", that is loudest near the air filter. I opened up the airbox, and it is definitely pretty loud coming out of the air intake pipe. Sounds like you are hearing the engine firing. The car also seems very underpowered, and is blowing more black smoke than usual.
My thoughts so far are head gasket, intake valve stuck open, or possibly a faulty injector. Anyone ever experienced this before?
After doing some research online it seemed like the EGR could be at fault. I took the intake all apart and cleaned a ton of carbon out of there. Reassembled with new gaskets, but the issue is still there. I really thought that was going to fix it
This is what the EGR valve looked like
This is the carbon that was pulled out of the intake
This is what the intake ports looked like
Last edited: