E320 CDi won't go over 95mph, sluggish at take off and with lots of smoke

[vadeyemo]

Please help. My car brings out black smoke from the exhaust when moving from standstill and when going between gears on the motoway, it gives out some smoke. Amazingly, this problem happens intemittently. My Mechanic ha s advised that the Air flow mass is faulty but going by what members have been contributing in the forum, I am not sure. Could anyone please help.

Victor

 

[IDMerc]

Smoking CDi

You don't say how old or how many miles your car has done. One point to check first - the air filters on CDi engines have a supposed service life of 75000 miles! OK they still work - but I changed mine at 50000 as my E220CDi was smoking as yours and the problem disappeared, engine much smoother, performance better.

Cost - £18.75 inc VAt for a stealership

 

[jberks]

I assume they are talking about the airflow mass sensor - it measures the amount of airflow going into the engine and allows the ecu to adjust the fuel supply accordingly so you getthe right mixture. Symptoms sound about right if its over reading (|ECU thinks there is loads of air going in so pumps in loads of fuel) though normally the ECU detects the problem and you wouldn't get to 90!
The sensor is the wired circular device in line in your air intake pipe after the air filter. Its a very simple job to slot in a new one (£200-£300 roughly for the part) and you're as good as new.

 

[vadeyemo]

Thanks for your contributions. I have just done a full service so I doubt if its the Air filter. Does a warning light come on when the Mass Airflow sensor is faulty? I have another problem today. The ABS/BAS came on, then ESP, then EPC, and the car lost power and felt very heavy. I am not actually sure of what i s wrong with this car. It's a 320 CDi Auto. Please help.

 

[jberks]

Some models do have a warning light though as I said above, it sounds like the ECU doesn't know the sensor has failed - hence no warning light. When my MAS failed I had no warning lights.
The ESP etc warnings are usually related to the brake light switch (very cheap fix) but the fact that both problems occurred simultaneously implies a common cause that would rule this out.

The only way to get to the bottom of your problem is to stump up for a proper MB specialist (dealer or indie) to go through it and pull the fault codes from the ECU. It could be something as simple as a small electrical fault or relay that is causing all your problems. Even a dodgy battery could do it theoretically. Remember, these cars are almost entirely computer controlled so a seemingly unrelated issue can cause lots of different systems to throw a fault. This also means IMHO that a jobbing mechanic, no matter how skilled and willing, cannot maintain these cars, you need a specialist with the right computer kit.

 

[vadeyemo]

Thanks a lot Jberks. Much appreciated. I took the car to a specialist indie who used a Bosch Computer to pull out the faults. He cleared 1 error in the MAS and tested it by reving the engine and he said it was working fine.
He also cleared all the error in on the BAS ESP ABS and EPC. I drove the car round the corner and then errors came back on.
The computer recorded that the rear right wheel ABS sensor's packed up so I will need a new one.

Upon clearing the MAS error and 1 error in the gearbox (possibly related to safe mode - not sure), the car seemed to pull better but what still wories me is the fact that black smoke still comes out of the exhaust when I move from standstill. I can't test if the car will go over 3k revs at the moment because it is running in safe mode. ABS sensor on order from Merc, cost £61 + VAT and the car has been booked in for next Weds.

Jberks do you reckon the EPC error may have a connection with this too? All the errors came at the same time. The indie said it should clear out. He also tested the wheel with the ABS sensor by getting someone to roll the wheel manually while he operated his computer.

Car feels heavy, no cruise, although I have not checked the battery as you suggested.

 

[jberks]

I'm surprised that safe mode kicks in with an ABS/ESP failure. In my experience it doesn't. Also a MAS fault doesn't normally go away either. It may take a few mins to come back or else exceeding a certain speed, but the fault is that it reported a signal that was outside its acceptable range. Once its done it the first time, it will do it again, so I suspect you are in for a new MAS in order to cure the fault.
It doesn't surprise me that you get black smoke in safe mode though so I wouldn't worry too much about that yet.
I'm not certain how a diesel behaves in safe mode as the only one Ive had was a petrol (hopefully I won't find out soon either!) but if the settings are out of skew then chances are it won't be burning efficiently.

 

[OlafMaxwell]

Mmm I have just got a similar problem, ABS etc lights came on some time back and the car intermittently seems to be in safe mode. I have checked air filter, seems fine, car feels heavy, kick down is off line sometimes and the turbo also seems off line. They are alsways both off line when the engine is hot but there are no temperature problems.

Anyway I booked car in for service in about 2 weeks. Going on what I read here before the MAF can develop inrtermittent faults and it seems probably advisable to replace it as it can cost as much to carry out the checks to eliminate it as the source of trouble. I have no lights showing up brake or any other problems.

Interested to know more. Car has 104k now.

 

[dogsbody]

e320 cdI WONT GO OVER 95 MPH, SLUGGISH AT TAKE OFF AND SMOKE

Having recently posted the same problem with ABS/ESP/Cruise all indicating error, and the car in safe mode, a sum of £7.57 plus vat was spent on a new brake light switch.
You car was showing the same problem. If it happens again, switch the ignition on, then apply the footbrake. If the system does not go into safe mode until you apply the footbrake, then it is the brake light switch...
If it comes one when you put the ignition on, then it is another circuit, tirggering the same problem.
On diesels smoking, there are basically one of two problems.. Either too much fuel OR too little air.
I would suggest that you look at the air intake, the air filter and the pipework to the inlet manifold. Do not assume because it has been serviced it is OK.
I had a RR diesel some years ago with the same problem (On a boat) and the air filter system was OK but the pipe from the filter to the manifold was "sooted up" and this was restricting airflow .. believe me it is the stickiest nastiest soot you will ever want to deal with!
The other thing which comes to mind is that you may have a duff injector.To test simply slightly loosen the feed pipe to the injector, one at a time..on tickover. The engine note should change.. if one cylinder does not change the tickover speed, then you have a duff injector.

 

[malcolm E53 AMG]

I own the same engined vehicle so am interested in how you resolve your problem. I have done some research on the high pressure diesel injection system and found the following site very informative:
http://www.turbocompressori.net.
Hope this helps!

 

[vadeyemo]

Thanks for all your contributions. All the warning lights (BAS, EPC, ABS, ESP) disappeared when the ABS sensor on the right rear wheel (£67+VAT) was replaced as diagnosed by the computer.
The problem with the air intake still exists. I will check out the injectors first. Do faults with injectors appear on the computer?

 

[Parrot of Doom]

Might be worth bunging a bottle of diesel injector cleaner in there, and giving the car a bit of a drive?

 

[tamrsoft]

Dogsbody

I read with interest your advise for testing for a faulty injector at idle. When you say loosening the pipe to each injector in turn, on the CDi engine do you mean the signal lead to the injector rather than the feedpipes since these will be at common rail pressure. I have also noticed (as you have mentioned) that the air intake manifold can soot up quite dramatically due the EGR gases and presumably should be cleaned out at some stage in the engines life.

 

[maddog]

You don't say how old or how many miles your car has done. One point to check first - the air filters on CDi engines have a supposed service life of 75000 miles! OK they still work - but I changed mine at 50000 as my E220CDi was smoking as yours and the problem disappeared, engine much smoother, performance better.

Cost - £18.75 inc VAt for a stealership

I have done 42000 miles on my e320 and changed the air filter 3 times!!

After about 10,000 miles i can feel the engine holding back a little and the fuel consumption goes up so change the filter and it feels fine again, cant imagine what one would be like after 75,000 miles!!!

 

[Dunhamkid]

Have you considered a faulty EGR valve. Had the same symptons on a diesel Polo,

 

[vadeyemo]

e320 cdI WONT GO OVER 95 MPH, SLUGGISH AT TAKE OFF AND SMOKE

This problem has been solved. I took the car to an Indie who used the Star Machine to diagnose the problem. The computer came up with a series of options. Eventually, they asked for my permission (more money) to look into the EGR valve.
Apparently, the EGR valve has been clogged by soot. This affected performance and the engine.
A new EGR costs 275+VAT from the Dealer but the Indie said he can take it out, and use a pressurised pump to get the soot out.
Having spent nearly 2 weeks (In between their own work) to find the fault, plus other work like replacing the transducer, changing the transmission fluid and other small jobs, I got a bill of £650.
I must say that the car takes off like a rocket. The Indie actually asked if the car gad been chipped as he said it is faster than any of the 320 cdi that he had ever driven. He was serious about it. Can someone tell me if this could have been done by the previous owner?

Every drive in this car gives me absolute joy and appreciation of the solid engineering that went into this car. I don't think I want to drive a smaller car now. I have tried driving my wife's Pajero and I feel terribly under powered - its like driving a tank.

 

[psmart]

Sounds very possible, ie. chipped. I had mine remapped (ECU memory chip reprogrammed) and it outputted a lot of black smoke when you booted it, so this could account for your EGR valve being all gunged up. My car became highly responsive after chipping as well. Trouble is, evaluation of possible detriment to your car. I bought the equipment and returned my car to standard (a little problem along the way) and after reading what the remap does (keeps your injectors open for a lot longer into the power stroke, ie. the explosion stroke, so at a minimum, your injectors are going to take more hammer), Im reluctant to re-chip it. Currently looking at larger injectors and I have contacted a guy who can create a custom map, so this might be the route I take.

I know from petrol cars Ive owned (MG Montego Turbo, RS Turbo, Cosworth), which I chipped, that it drastically reduces the life and increases the bills, but at the time it was worth it, for the adrenalin rush!