638 108CDI popping noise at start up

Hi ya, at a guess you are refering to the Diesel filter and one of the lines is not fitted properly. The noise is more puzzeling, if it is more of a chug chug sound it could be a loose injector or injector seal gone, the only other thing i can think that could cause a poping sound is a stuck egr valve. If you can take a picture of the canister and post it so we can identify it


Cheers Martin

Hi ya, when you start it up stick your head under the bonnet and see if you can smell or see diesel fumes coming from under the plastic engine cover and look at the right side of the engine bay for a rubber tube that goes nowhere. If there is gunk coming out of this tube or what looks like oil running down the back of the engine ti points to an injector seal gone. The rubber tube is a leak off pipe from the space in the middle of the rocker box where the injectors sit. If there is gunk coming out of this it is diesel that is blowing past the injector seal.


Cheers Martin

P.S the noise goes away as the engine heats up because the metal expands and blocks the leak from the seal