Is the trans set to winter or summer? May be as simple as being set to winter and reducing available torque.

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Terry Allison
N. Calif. & Boca Chica, Panama

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

I had the trap oxidiser plug up in my 87 300TD.

This was the replacement one that was included in the entire exhaust replacement recall of years ago.

Symptoms were low power and lots of black smoke.

I dropped the exhaust aft of the turbo, and it was clear almost immediately that the exhaust was plugged. Car obviously ran much better with the detached exhaust. It was noticable even running down the driveway (300').

A simple tool made from a piece of rebar sharpened like a flat blade screwdriver made short work of the plugged matrix w/o any outward signs of tampering.

Jim

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14 E250 BlueTEC black. 45k miles
95 E320 Cabriolet Emerald green 66k miles
94 E320 Cabriolet Emerald green 152k miles
85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles

We did replace a whole bunch of parts after a full diagnostics of the CDI

We had fuel pressure issues that threw the car into limp mode as well as noise LP pump.

What I also need to mention is that the P.O run the car for approx 50K miles on Biodiesel...

So what happened was that he got the limp mode and dealer assumed the whole car fuel system is dirty and needs to be replaced. I took a chance on the car and bought it.

The fuel pressure problem went away after we swapped out the fuel pressure sensor at back of the fuel rail.

The noise fuel pump aka lift pump aka low pressure pump was replaced with a new one along with a fuel sender unit.

Additionally the HP pump was replaced due to a stuck internal fuel return valve.

MAF was also replaced since we did not get any readings from it.

So right now the car runs good. No codes and and engine runs smooth. However the issue of low power remains.

Why I think I should revising the CAT is because we disconnected at the turbo but did not really drive the car at a good speed to notice a difference. Sure the turbo was spooling up louder and I did notice the electronic VNT actuator move as it should.

So I think I shall go back, unplug the CAT and go for a boot in the car.

Another suspect I have is a blocked intake manifold. However when I pulled out EGR valve it was clean as a whistle.

Now back to the point where PO used Biodiesel in the car: The car had already approx 30-40K miles when he started using biodiesel.

I do not have sufficient knowledge of biodiesel but I know MB allows only something like a 20% blend with petrol diesel. Well from what I gathered the PO run B100 or 100% biodiesel.

From what I understand biodiesel burns clean and acts as a detergent, cleaning out crap and such from the engine. In theory, is there a possibility where a whole bunch of gunk and crap from the combustion process clogged up one of the cats over the last 60K miles?

I have not done any 0 to 60 times. The car seems fine but lacks that responsiveness.

I have switched bet Winter and Summer mode but not big difference in response.

If I hold the car against brakes and let turbo spool up it takes off, but I am unable to activate traction control. Also there is very little black some if any when I floor it.

Thanks guys,

Biodiesel.......

From what I am hearing from some other diesel owners, biodiesel is a no-go.

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'06 E320 CDI
'17 Corvette Stingray Vert

I wonder if it would help to test drive another one....see if your subjective impression is any different.

And have you done the 0-60 test yet? That would seem to be in order.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 159k miles
06 E320 CDI "Rutherford", Black on Tan, 179k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 77k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Hi guys and thanks for the input

The car does have a OE CAT, we took off the clamp and looked inside of it to verify, we can see a mesh type honeycomb which is not blocked.

Looks like the OM 648 motor E320 in NA have one CAT right after the turbo and then 2 rear mufflers.

I do not believe the exhaust is the culprit.

Mass Airflow Sensor under load 900MG of flow.
Boost pressure 2300MBAR
Rail Pressure 1600 BAR
Removed clamp on downpipe and test drove, no changes

New fuel filter, new air intake temp sensor new pressure boost sensor, new MAF
New thermostat runs at proper eng temp.

I cleaned intake and checked intake port flaps and all ok. Also did the test on them on the car.

I have comparison to same car that has a much better perf.

0 - 60 is around 9 sec.

Like I said car runs well with no stored codes.

I do not hear any boost leaks, do not see any issues with that.

EGR is clean and was clean when I first removed it.

Seems like I have reached all the items I can check...

excerpt from Car and Driver test report:



Nevertheless, the diesel is quicker to 60 mph-7.1 seconds versus 7.4-and delivers more punch in low- and midrange sprints: 30 to 50 in 3.5 seconds, 50 to 70 in 4.8. The gas E320 recorded 3.8 and 5.4 seconds, respectively.

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96 E300d