Hi everybody, first post on this forum & i'm a newbie with a glow plugs question. Ive tried to do as much reading on the subject, but as with all things online, there is lots of conflicting info. Basically i have a W211 E Class 320 CDI Sport which i have owned for just over 1 week. I love the car and runs fine, but every now and again it is slow to start and takes an extra 3-4 seconds. I always wait until the glow plug signal turns off, and it generally takes 2-3 seconds to turn off if the car is cold, or 1-2 seconds if it is warmer. I have a few good spec diagnostic tools and so far have used the MD802 to diagnose the following codes P0670 - Generic regarding the glow plug module circuit being open. As i understand it, the circuit WOULD be open, if there was a faulty module/relay, and it would also be open if there was a faulty glow plug. I then used the more advanced part of the tool to get the following codes 2270-4 which i think is the Mercedes equivilent to the P0670 code, (description reads at least one of the glow plugs is not actuated) and an additional 2137-4 (description is glow plug cylinder 5 open circuit) So, is it as straight forward as the cylinder 5 glow plug needs to be replaced? I have read that a lot of people have got the P0670 code and simply replaced the module which has cured a lot of problems that owners have. Oh, i would say that i have a little more smoke coming out of the back end than i would expect, but not industrial amounts. Any help is appreciated, or any better advice as i'm keen to learn more on this subject. Many thanks.