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Hey all, new here. Have an E320 05' CDI bought last year. The car came with only 2 issues: 1. LIMP mode being activated on highway speeds 95kms + that resets by turning engine off and on and coming with a check engine light with a turbo underboost code. And 2. A tranny with rough cold shifts from 1st to 2nd gear.
Now I've decided to tackle the first issue since im going on a long trip and don't want bad mileage driving on limp/any issues.
I've done multiple times since buying car: fuel, oil, air, tranny filter change, MAF and EGR cleaning with sensor spray, lucas oil fuel cleaners every 3 refills and muffler replacement due to broken pieces inside mufflers according to my mechanic.
Furthermore mechanic checked car with mercedes diagnostic tool and found catalytic converter code as well as a tranny code along with turbo underboost i found with regular scan. He think cat is the issue and im thinking cat delete to test this prior to purchasing new catalytic con?
Thanks guys searched on forum but nothing exactly similar
Last edited by BrajCDI; 09-01-2016 at 10:59 AM.
Reason: Forgot something
First you oughta calm down, as you may not finish the trip---secondly, I have read the post a couple of times and always have difficulty getting past "Hey."
Perhaps you could simply list the DAS fault codes and what you did to correct the faults, if any
First thing you do is don't listen to that plonker above and wait for someone with some credibility to answer, what's the mileage on the car? The vnt mech on cars can get clogged up, esp if by the sound of it your light on the throttle trying to achieve good mpg, have you been out and given it a good blast when you use these fuel adatives? The cat can also be clogged but if it's badly clogged then usually you'll find a covering of soot around the hot side of the turbo as the pressure forces gassed out of the joint.
The exact code numbers does help and also if the codes are current and not old codes.
First thing you do is don't listen to that plonker above and wait for someone with some credibility to answer, what's the mileage on the car? The vnt mech on cars can get clogged up, esp if by the sound of it your light on the throttle trying to achieve good mpg, have you been out and given it a good blast when you use these fuel adatives? The cat can also be clogged but if it's badly clogged then usually you'll find a covering of soot around the hot side of the turbo as the pressure forces gassed out of the joint.
The exact code numbers does help and also if the codes are current and not old codes.
P0299 is the underboost code.
P0420 is the Cat code.
Then I get a tranny code which I don't recall and doubt is related to the limp mode. Yeah I've ripped it on highway often and noticed the smoke behind me on the rear view mirror when I redline it. With and without additives there's smoke, not sure if normal with diesels or not.
The code p0420 is for under efficiency, basically it's not doing its job properly, I'd be surprised if it's pulled that code from running too rich but it's not impossible, does the turbo sound loud? is the whistle more pronounced than usual? have you checked for boost leaks? The symptoms of a boost leak can be smoking on boost and limp mode due to underboosting have you noticed bad fuel consumption since this limp mode has started?
A properly running diesel thats not heavily tuned should have a slight haze of smoke in the headlights of the car behind at night, in the daytime you shouldn't really be able to see the smoke, a car with higher mileage may smoke a bit more due to worn injectors and dirty inlet tract, also if the car has been driven gently for a while and you give it a poke it'll puff out some smoke till it clears it's throat of soot.
Its at 170k miles atm i got it at about 130 (I drive a lot)
I suspect my mechanic did check boost for leaks, I will double check. He used to work on Merc dealer and now operates a Merc Sprinter shop.
Its not black smoke unless I have an additive in it then i notice its black and sometimes stinks but usually not. I have a sprinter as well and to be honest the w211 turbo doesn't whistle like the sprinters and only "howls" on redline that you can hear it noticeably
Stinks? As in acrid smell like it hasn't got a cat? What colour is the smoke normally?
Yeah exactly it has a burnt/strong pungent smell for a few seconds randomly at times. Not sure if thats just the cat burning the soot like its supposed to but also has black residue at the exhaust tips.
The smoke is usually white/grey but with the additives it gets darker. Its visible daytime, yes.
I think amongst other things you may have leaky injectors, that is probably irrelevant to your underboosting condition though, but could have damaged your cat in the process, if your mechanic is quite friendly, ask if he can check smooth running with star whilst he's having a look.
White/light grey smoke that smells acrid and "fuelly" is a clear indication of unburnt and inncorectly atomised fuel.
The diesels I did drive have engine breather on turbo suction pipe, so any intercooler leak will show as wet, oily stain around.
I like to check cats with infra red thermometer, what is easy.
Others say that removing O2 sensor will let them see if open exhaust makes the difference.
Transmission acting? When was pilot bushing last time replaced?
Heres inside of the CDI's turbo after removing the CAT.
BTW is that little rod on the middle, outside of the turbo (wastegate actuator i think its called?) supposed to move easily? I pushed on it a bit with a screwdriver and it wouldnt budge. Not sure if it only does when u accelerate electronically or what i didnt have anyone to test it with.
Those turbos don't have waste gate, but variable fins.
The outside mechanism is servo motor.
Not sure you can push servo with hand, but the rod should easy push the fins, meaning hand push should give you at least some play.
Open turbo inlet and check the movement.
Disconnect the actuator arm (black box) on the turbo and see if the VNT mech is free to move, it should be pretty easy to move once the actuator is removed from it, as mentioned above.
Oh and that CAT is toast now, did it look like that before you blasted it? The best thing to do with that cat is remove all its guts and drive without it, all the honey combe that's broken up will be blocked in the cat and if it wasn't causing excessive back pressure I bet it will now.
Disconnect the actuator arm (black box) on the turbo and see if the VNT mech is free to move, it should be pretty easy to move once the actuator is removed from it, as mentioned above.
Oh and that CAT is toast now, did it look like that before you blasted it? The best thing to do with that cat is remove all its guts and drive without it, all the honey combe that's broken up will be blocked in the cat and if it wasn't causing excessive back pressure I bet it will now.
Right so I gutted out the CAT and reinstalled it, now I get code P0401 (insufficient EGR pressure) and am in constant LIMP mode. I cleaned out the EGR valve, it was slightly carbonated after removing it from the housing but not much; same thing...Any ideas or do I need an actual CAT to fix this?
Ok its back to normal now after driving it a bit more, however I still get LIMP randomly but with the EGR code above instead of the Turbo Underboost I originally had. FYI I used Silver Grade Anti seize on the EGR piston and rotating knob after I cleaned it up, not sure if that messes up with the magnetic or whatnot. But everything else i made sure to replug, etc.
Sorry I never got back, being a us spec car I couldn't say whether you'd get a emissions light or not, euro3 usually doesn't throw a light up until 03-04 in uk spec cars, pretty sure it's mainly euro 4 that do it but right now I can't remember.
The EGR pressure code I don't think would be cat related, unless it can sense the reduced back pressure in the exhaust now, I would think a lambda code or emmisions code would be present instead.
Sorry I never got back, being a us spec car I couldn't say whether you'd get a emissions light or not, euro3 usually doesn't throw a light up until 03-04 in uk spec cars, pretty sure it's mainly euro 4 that do it but right now I can't remember.
The EGR pressure code I don't think would be cat related, unless it can sense the reduced back pressure in the exhaust now, I would think a lambda code or emmisions code would be present instead.
Yeah code went away completely over the span of a day and no more limp mode. No CEL either just a weird noise with hollowed out CAT. Cheers guys
Does it sound like a coooo noise or is the turbo just more whistley? Either way it's normal behaviour once the cat is removed, is your white smoke gone now?
On my '05 E320 CDI, the EGR kept fouling up and setting a code. I ended up taking it to the dealer and getting a new EGR "and" had them reflash the brain box for the new 'upgraded' EGR valve.
It has been over 100,000 miles and no new problems. An EGR failure at 50,000 miles should be a warrantee thing but with its reliability, I don't care.
BTW, mine runs great but it is not a 'clean' diesel and will smoke when floored.
09-01-2016, 10:56 AM
