theCougAbides

First post. I bought a used 2012 ML350 Bluetec with 105k miles on it a few weeks ago, and I've been lurking here ever since. I loved it for two weeks. The car is immaculately kept, service history is great, Euro specialist mechanic bought off, ran great...the torque, power, features, most comfortable car seats ever, plus it's a gorgeous pearl white. Never liked a car as much as this.

Then the limp modes started happening. My OBDII code (cheap, not STAR), keeps coming up with P0405 - EGR Sensor A Circuit Low. The freeze frame data doesn't always show anything wrong, but my OBD scanner is Bluetooth and I can see live data on my phone. I looked specifically at the "Commanded EGR position" vs "Actual EGR position", which are consistent when it's cold but deviate wildly when it warms up. So I took the EGR valve off, cleaned it up (not much to clean), and put it back in. That didn't solve anything. I ordered a new EGR valve which will be here in a few days.

The soot level in the EGR and inlet/outlet pipes was minimal, only a very thin coating. Nothing that should matter. The previous owner got oil changes at a Mercedes delaership, but I bought the car from a Toyota dealership. The Toyota dealership changed the oil and filter prior to selling. From that oil change to the time of EGR problems was about 1,500 miles.

So I have a car that never had an EGR, exhaust, or intake problem (according to service history) prior to about a week ago, one which the proper oil was installed up until 1,500 miles ago. I have no idea what oil the Toyota dealership used, I can only assume it wasn't the right stuff. Finally my question: Is running the car for only 1,500 miles with the wrong oil enough to break the EGR valve?

Thanks for reading, I hope the new valve works out because I really want to love this car. I would have just done a EGR, DPF, SCR delete but I thought I should be sure I have solved the problem before i go messing with that stuff.

Chamelleon

Hi.

Try to ride the care pushing it with a full throttle up, of course, obeying the speed limits.

In this way, the system might clean up the valve and DPF by itself.


... and urgent change the oil, oil filter, engine air filters, fuel filter.

You also might want to take a sample of old oil to the laboratory.

Go well!

ducat2242

my 2013 ML350 does this as soon as i put lower quality diesel in it . I was forever resetting it only use hi quality diesel and it never happened again . Dont think the oil will cause problems like this .

theCougAbides

Interesting. I just got the car and have only used two stations to test them out. So this happened immediately after the second fill-up, which was a 5% biodiesel station. You might be on to something. I do use a Power Service Diesel Kleen + Cetane Boost. Was going to go a few tanks with and a few tanks without to see if there was an MPG difference. Doubt the additive would cause problems though.

theCougAbides

Update: I put in a new EGR valve and oil catch can about a week ago and it's been problem free. As I said in original post, I was tracking EGR valve position Commanded vs Actual, it was all over the place. Now the two graphs look the same. No limp modes, no CELs.

FYI, the catch can caught about 2 Tbsp of oil in a week (~400 miles). Cheap add on, highly recommend.

Next up: wait for the SCR or DPF to malfunction so I can delete them

pgsurface

I've been waiting for a long time now; 137k miles on my 642 powertrain and no emissions related failures............ yet. Only took my Ram 8 months!

dave2001auto

What oil catch can did you install? Any pictures.

Jose3147

Did he ever posted a picture of the catch can. And set up ?

rmassmann

I had to complete the dreaded oil seal leak repair on my ( 2012 ML350 BT ) short after I got it in January of this year. Due to the items that needed to be removed I found a larger quantity amount of soot accumulation after the EGR is introduced into intake air path just after the throttle flap servo. See photos of the soot accumulation. Soot I believe accumulated due to excess oil from the crankcase vent valve, which I replaced. Please note that the crank case vent valve ( PCV ) is covered under an extended warranty program due to the legal settlement with US government. This was similar to what VW had done with their diesels on not to the same extent.

2012 ML350 Bluetec 87K miles


Soot Collected, intake, left intake manifold, right intake manifold

Soot accumulation intake after throttle valve

80 % of the soot accumulated