E320 Issues

[franklyspeaking]

I bought this car 7/22 with 151K, knowing very little about it with the exception that it had a very long range and a diesel engine. I wanted it to pull a teardrop trailer to Alaska and back from Alabama. A 9500 mile trip. I was looking for a diesel that did not require DEF and this one seemed to fit the bill. I noted that a certain type of Mercedes Oil was recommended, but that was nothing new to me as did all of my other Mercedes cars I have ever owned. I did not know about the DPF needing a special oil. So I have now put 30k on it and it now has 181k (including the 9500 mile Alaska trip). I used Mobil 1, but not the special kind.

I have several issues going on. 1) It is due for an oil change. I plan to change to the correct oil on this change. Have I done irreparable damage to the DPF? It seems to accelerate well, and gets 33 mpg on the highway. 2) It has a leaking rear main seal and as soon as the weather warms up a bit I plan to change it. 3) I had to recently replace the EGR valve and the Batwing, and during the EGR episode it threw the 2633-001 code (MAF Sensor Drift under load). This code remains, but no other MAF codes are present. I am now having some trouble getting it to run smoothly. It intermittently becomes jerky when accelerating mildly. During rapid acceleration it smooths out and sometimes then smooths out in all driving after heavy handed acceleration. However, when it is shutdown and restarted the jerkiness begins all over again.

The final question I have is does this code that refuses to go away have any impact on the drivability problems I am having? There are no other codes besides that one. Any ideas on what to do?

[Sugar Bear]

The only question I'm comfortable in answering is that I HIGHLY doubt you did any damage to the engine by not using the exact spec. oil.

[WaarrEagle]

Use the right oil going forward. Any damage to the DPF is done but the good news is that you are not getting any DPF codes. Hopefully you got lucky.



Your other symptoms indicate a classic boost air leak. There are several common leak points... check the intercooler hoses for cracks, the orange seal at the turbo, the o-rings at various connections, the pcv seal, pretty much give the system a good once over. The EGR is another possibility given you had it out. I chased MAF drift codes for a while and after replacing much of the above I am code free now.

[franklyspeaking]

I was able to get rid of 2633-001 code by rapidly accelerating up to 80 mph with the engine warmed up. I found that when you do this the car will then run smooth with no jerking at any speed or load condition. After getting it into that state, the 2633-001 code goes into historic from current and can then be erased with my icarsoft 980. It has not come back on. However, the jerkiness begins again after restarting the car. So now no codes, but jerkiness remains. I noted tonite that if I drive as a manual shift car it does much better when keeping the RPM up. It seems that the transmission in Drive mode is lugging the engine down and making it buck or jerk. It takes out like a banshee when you goose it and accelerates as smooth as silk. I also checked the transmission, but there are no codes for either the engine or transmission.

[WaarrEagle]

Have you tried resetting the MAF adaptations? Or comparing the MAF sensor readings to see if they both look valid/similar? You have to assume a code will come back if it is running that bad.

[franklyspeaking]

Have you tried resetting the MAF adaptations? Or comparing the MAF sensor readings to see if they both look valid/similar? You have to assume a code will come back if it is running that bad.

Don’t know how to do this. Can it be done with my icarsoft 980? I have viewed the data readings and the sensors look reasonably close. I have new filters and I am going to change them. Also, have a new fuel filter on order and will change it also. Both air and fuel filters have about 20k on them.

[franklyspeaking]

Just as a follow-up, I have solved the problem. I changed the MAF’s with known good Bosch ones, and the car now runs pretty smooth. There is some minor stuttering, but 99% gone. There may still be issues with the EGR valve, since it is a Chinese knockoff.

[WaarrEagle]

Glad to hear. Resetting the MAF adaptations may fix that last bit of stutter. The manual calls for it when replacing the MAF (or just replacing the air filter).

See if your tool can manually activate the EGR valve as that may help you diagnose if it is having problems.