320cdi EGR power loss when Cold

[masterwest]

Hi There

This is my first post to the forum

I have a 320CDI estate year 2000, i have had it now fo rbetween 6 months and a year, it used to chuck out lots of black smoke and loose power everynow and then, but pulling over and restarting it would cure it.

couple of months ago when it got hot it cut out i changed the CPS which cured that perfectly.

after this success i thought i would have a go at the previous problem,cleaned and evetually changed the MAF, car defibntly runs better and more MPG or so it seems, but the power loos problem is happening more frenquently now but only when cold, when warm it hasnt done it since changing the MAF.

I have been reading some of the posts here and i am not quite sure if its a easy job (or quick) to change the EGR on this model, and seen a lot of posts on making a shunt for same.

I hope to take the plastic covers off toninght and maybe try to locate the EGR to see how difficult it is to get to, can anyone confirm this is the thing i should look at next? and possibly what they would recommend.

Thank you for your time

David

 

[dieseljock]

Hi David,
welcome to the forum..The EGR is located underneath the left hand side engine cover ( on your right as you look under the bonnet), the one held on with 3 screws. Once you have the cover off you will see a long stainless steel box section connected at the far end to the engine block, and at the close end into the EGR housing. The egr itself is a bit fiddly to get off, you're best raising the front of the car a bit(I used blocks, but whatever you use, make sure it's safe before you go crawling under your car) and taking off the splash guard from beneath the engine. You need to take off the large metal pipe connecting the intercooler to the inlet manifold, that will let you access the three screws which hold the egr assembly to the manifold. You will also have to take off the egr cooler, which means draining the coolant- you do this using the drain screw on the bottom of the radiator on the same side the pipe you are removing is on.The best thing for cleaning out the egr valve i found was diesel and a tooth brush..Maybe 4 hours all in to take off, clean and replace..
my 320 is the same age as yours, and I wound up stripping the inlet manifold off and cleaning it out as it was totally gummed up with soot.. That soot had also seized the swirl flaps which block off half the inlet at low engine load levels to accelerate the air going into the engine and improve the mixing of fuel and air. I would check these as well-they are all connected by a flat bar which runs along the underside of the manifold, right beside the engine block, and which is moved by a small motor mounted underneath the manifold, via a small linkage with a ball joint either end. This has a habit of coming off when the flaps stick. you can check the function by starting the engine and revving the throttle- with a torch you should be able to see the flat bar moving back and forward- either that or the pivot on the motor rotating if the bar has come off..If those flaps stick, that can cause smoking and lack of power too. The only fix for these if stuck is taking off the manifold and cleaning.. The problem you are having which sorts itself out when you switch off the engine definitely sounds like the egr.. It is possible to remove the actuator for the egr valve, the small cylinder attached to the egr assembly, and free up the valve with wd40-this might give you a short term fix, but if the manifold is gummed up, it'll come back..
Anyway, here is a link too me sorting out my e320's smoking habit, mine has 150,000 miles on it, and after a bit of tlc, it's now running like new..
http://forums.mercedesclub.org.uk/showthread.php?t=75707