Good day folks

Got a 2005 E320 CDI 118k miles. It just seem sluggish and underpowered. Seems to be lacking the torque it should have.

This is my first CDI car in family. I have not driven any other CDI I6 to compare.

So its got new fuel and air filters, Clean EGR system and no check engine lights. New air intake temp sensor and new MAP sensor.

I still think the damn thing does not have the grunt it should provide. I had car scanned on MB star program and no faults found.

Would a clogged air intake make such a great difference. Would there not be some sort of fault code for it?

What about the injectors? Car starts up great and has no smoke under heavy acceleration.

Fuel milage in town is ok, not great 13l to 100km..

Thanks

Possibly........but I doubt it. I would guess that it depends on your perspective.

My CDI is like driving a leashed stallion. It always wants to pull and run like a scalded ape. Just a fraction of a steady kept push on the foot feed produces a 'kick' in each gear shift change propelling you forward.

What do the records you got with the car indicate?

__________________
'06 E320 CDI
'17 Corvette Stingray Vert

Those cars have so many sensors that it's hard to imagine a problem that would not be flagged by one of them.

Just speculating, I would say look at the VGT actuator and possible cat flow problems. Just a "gut" feeling, I know nothing of these...

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

I agree. Lot of sensor. We got the car with a limp mode and went from there to fix it.

We did the sensor at back of fuel rail. We had issue with the HP pump where a internal valve did not return fuel properly to fuel tank.

We replaced the MAF sensor. We also replaced the LP pump in fuel tank and fuel sender unit.

A lot of work has gone into her. Right now runs great, no codes yet low on power.

So I am coming back to the cat converter issue. While at the shop few months ago. We did disconnect the exhaust just AFT of the turbo. Thus running it without the primary or secondary Cats..

The mistake we did perhaps was the way we tested it. Only went on a short run outside of shop. Did not notice a great difference so we bolted everything right up.

Seems like I shall revisit the CAts again.

I guess I'm a little confused but if you disconnected the exhaust system and nothing changed why would you have to re-visit the issues of the cat's being clogged?

Seems like you've already replaced a bunch of parts, was there any diagnosis done before they were replaced? If so did the replacement of the parts cure whatever issues were discovered in the diagnosis process?

I can second Skid-rows comments, my CDI comes off the line with real authority. Traction control can be activated at will with full-throttle applications on dry conditions up until around 20-30mph.

0-60 times are in the mid 6 second range and accompanied by lots of nice black smoke. If yours isn't acting like this something is amiss.

__________________
98 Dodge-Cummins pickup (137K)
13 GLK250 (157k)
06 E320CDI (341K)
16 C300 (89K)
82 300GD Gelaendewagen (54K)

I'm wondering why people are having stopped up cats? I didn't know these cars' cats were so short lived, or that they even ever stopped up. Or do they?

__________________
'06 E320 CDI
'17 Corvette Stingray Vert

Over the years I've only ever seen one plugged up cat, on my son-in-laws Dodge truck. It wasn't a very hard diagnosis as the truck had no power at higher revs and the cat glowed cherry red. I've made a test-bung that threads into the O2 sensor to check back pressure and it indicated something like 300 PSI of pressure at full-throttle. Typical good values are less only a couple of PSI so it wasn't a tough one. I've never seen an MB cat melt down and plug but I have seen them develop rattles when the ceramic structure inside cracks and this permits the ceramic matrix to rattle around inside the metal supporting structure.

Again its not clear to me that the converter is the problem here, if the original poster removed the exhaust system prior to the cat and nothing changed I don't see how the cat could be involved.

I do agree with the previous poster that given the level of computer management on the CDI's it seems unlikely that something could be really amiss and have nothing show up on the CE lights or SDS codes.

I'd like to know if the original poster ever did a 0-60 test and if so what were the numbers.

__________________
98 Dodge-Cummins pickup (137K)
13 GLK250 (157k)
06 E320CDI (341K)
16 C300 (89K)
82 300GD Gelaendewagen (54K)

13l/100km=18 mpg (US). That's worse than my 300D. Something is wrong, but I'm not sure what. I'm having trouble thinking of a powertrain problem that would create those symptoms without throwing a code. Have you checked for dragging brakes?

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

Its a lil low but in the realm of possibilities if you only drive in town and are VERY heavy footed......I'd probably look at the Cats too, although maybe there's a SBC brake failure going on? Worth questioning.

For reference, my 09 (OM642) gets ~25mpg in town lugging around at 1100-1200 rpm. Highway at 80mph it gets 38mpg; guessing at 65mph it would get in the low 40's. It does get up and roar whenever you put your foot down hard and challenge the traction control as another poster mentioned.

The Bio use concerns me, may be inj or pump issues still unresolved. I believe B5 is the max bio limit.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Gosh, my 2005 will fly; I try to stay off it because I don't like the smoke, but it will fly. It has 130K. I just made a trip out of state one day, averaged 40.7 mpg according to the on-board. I typically get circa 35 around town here (rural area).
BioDiesel? Uhoh...no telling what it could be. Injectors clogged? Turbo wheel dirty? Are you certain the trans is shifting into high gear? Is a brake caliper sticking/dragging?

__________________
Providing a home for these cars:
1951 Buick Special De Luxe
1977 Rolls-Royce Silver Wraith II
1970 Rolls-Royce Silver Shadow
1986 Mercedes-Benz 420 SEL
2005 Mercedes-Benz E 320 CDI
2012 GMC Sierra 1500 4X4
1927 Pierce-Arrow Series 80
1931 Pierce-Arrow Series 43
1926 Ford Model T coupe

thanks for all the replies. I am too scratching my head..

I think brakes are OK. I did several tests where I put car in N and it was moving without any binding on brakes. Unless the SBC system engages somehow during driving and impedes the wheels.

I bought diesel injector tester kit Lhttp://www.princessauto.com/pal/en/Testers/Fuel-Injection-Test-Kit/8504748.p

We will test the injectors in upcoming days.

Would it be safe to assume that the car would throw codes at me if CATs are blocked?

Update:

Had car at MB dealer and checked for all updates on software on ECU and Tranny..No changes after software reflash to latest.

Checked injectors and flow test them.

Checked Y values on High Press Pump


Cleaned out intake manifold from carbon build up. Wasnt bad at all, mild build up no blockage.

Replaced MAP sensor and air temp sensor on boost pipe leading into intake manifold of engine

Replaced MAF sensor at air intake filter with Bosch unit

Checked exhaust for blockage, nothing found,

The E320 CDI drives fine with no codes but still lacks that power it should have out it.

I am out of ideas of what to check next.

Is there a sensor that I might be missing, perhaps its giving wrong values to ECU?

I have absolutely no codes at all. Nothing stored. No limp mode. Revs to redline but aint got that punch it should.

Runs smooth, no black smoke,

I am about to give up. A car of this caliber with a whack load of sensors and nothing is showing up...

What am I missing?>

I just read all the posts on this thread and I haven't yet seen this question asked: What are you comparing your car to? Have you driven/owned another CDI, have you had another CDI owner drive your car? I think my car has lots of pep, when compared to most diesels and even gassers but I wouldn't line it up against a Corvette... maybe you are expecting more than what the car has to offer?
I am only saying that because acording to SDS all systems check out and there are no codes, newish HP pump, clean EGR which by the way, can trow the car into limp with no hard codes. Sounds like intake and exhaust are doing what they are supposed to. What was the outcome of the injector test? Did you check fuel rail preasure? Although that should come up in the SDS test if faulty.
Again, the CDI is peppy but it all depends on your expectations.

EDIT: BTW, my car doesn't smoke even when floored, at least not what I would consider black smoke like my old (2006) Ram CTD. The exhaust stinks, but no black smoke.

__________________
W211 B-PILLAR TRIM PANEL REPLACEMENT
My Continental Tire Experience

By Land:
2005 E320 CDI (Unnamed as of yet)
2011 Toyota Tundra DC limited 4x4 "Big Red"
1965 euro import VW Beetle "Mojo"
By Sea:
22' Grady White Seafarer "SeaSun Pass"

Make sure it actually has a cat. There is a problem with backpressure. PO could have removed the guts to the CAT and the Turbo is off because of lack of backpressure which sounds against all possibility but it creates a swirl in the cat without the ceramic material on the inside. Most people have to cut the cat to get the material out look for the re-weld lines.

My original CDI got better fuel mileage and had more power but not much. I always wondered if the first had a tune on it that I did not know about.

I run WVO in mine on a two tank system. It is a great car. It is even better when you use 3 gallons of veg oil for each gallon of diesel.

Good Luck.

Make sure it actually has a cat. There is a problem with backpressure. PO could have removed the guts to the CAT and the Turbo is off because of lack of backpressure which sounds against all possibility but it creates a swirl in the cat without the ceramic material on the inside. Most people have to cut the cat to get the material out look for the re-weld lines.

My original CDI got better fuel mileage and had more power but not much. I always wondered if the first had a tune on it that I did not know about.

I run WVO in mine on a two tank system. It is a great car. It is even better when you use 3 gallons of veg oil for each gallon of diesel. Mine never smokes either. Neither did the last one.

Good Luck.