rniebuhr

First, thanks for reading this. Second, any thoughts are appreciated.

I recently bought a 1999 E300TD at an auction for a great price. Upon investigation it has turned into something of an enigma.

First, there were numerous codes including MAF, Fuel Temp Sensor, etc; I managed to clear those through cleaning flaps, using MAF cleaner, replacing plastic fuel lines and o-rings on fuel shutoff valve. I have the Carsoft software from Belgium too, which helped ID airbag light issue too. So far, so good.

Trans was in limp mode--I got a new conductor plate and plug adaptor/trans filter and pan gasket. Did that job. Used carsoft to reset trans. Still limp-mode remained.

As I continued into this series of repairs I was confused; I had a 1996 E290 D (OM605 engine) before when I lived in South America. As I had begun to figure out what I wanted to do it seemed that the turbo was not where I had expected. I also had a Air Temp Sensor code but I could not locate that sensor/plug pigtail.

While doing the repairs that I mentioned above I came to the conclusion that the prior owner had removed either the turbo and converted to a normally aspirated motor or actually junked the original motor and installed a replacement n-a motor.

While having the normally aspirated version is kind of a bummer compared to what should have been there I would be happy to make this work. Otherwise, the car is clean and in nice shape.

There are two problems that I am facing right now: first, the computer is still from the e300TD and the airbox has the MAF sensor. I cannot find an air temp sensor that would be on a 1996/1997 n/a motor. No wiring and no place for a sensor that would seem obvious. I have read that the MAF controls that function and so I would assume that the air temp sensor would not have been on a 99. So, how can I clear the code for Air Temp Sensor? I am prepared to wire one up if needed but would need to know where on ECU.

Second, and the MOST IMPORTANT is the EGR. Mine has the 96/97 EGR located next to the air box but the plug was snipped and tucked behind the coolant res. tank. I cannot locate wires of the same color code, though, that makes sense if the EGR and wiring was taken off of a 96/97 and stuck into my 99. I have read all about the EGR delete . . . it is an option that I would gladly consider because it seems that the EGR is the (primary?) reason for the limp mode. Yet, I would be just as glad to simply install the EGR and have it function correctly. I can deal with soot--I already cleaned out the manifold and scrubbed the flaps; it is not a hard job. In any case, I think the correct installation of the EGR might be the more straightforward thing to do.

So, looking at things online it seems that the EGR on the turbo was on the driver side under the manifold. The EGR vac pump is there too, by the window washer fluid. Then, it seems with the turbo, the plug (marked "507") tucked up by the fuel lines in the back would also connect to the egr on the turbo.

I need to investigate more but I am thinking that I could simply buy vacuum lines long enough that use the turbo's egr vac pump. That leaves the electric connection an issue but if that part "507" is the egr plug on the 1999 maybe I could extend that wiring to reach over to plug into the egr on there now (from 96/97). There would be a few others odds and ends to figure out but wanted to see if anyone had any thoughts.

I know this whole situation is not ideal but I have to think that there is some way to get this motor to work correctly and not have codes come up/trans go in limp mode.

Thanks in advance.

MattieIce

So do you want to leave it as a NA or put a turbo on it?

rniebuhr

Frankly, I am fine either way . . . I don't want to buy the turbo and related parts new so I would need to source it from a salvage yard; that might be more trouble than it might be worth but I am open to the idea. My sense is that solving the EGR issue and allowing the flaps to flow correctly in the manifold/crosspipe will get me going and clear codes.

If you have an idea of the turbo and related parts going on as a feasible solution happy to hear the process. Thanks.

MattieIce

I think the easiest way to do this would be to convert to a turbo and delete the EGR. The ECU might interact with those parameters better since you do not want to probably do an ECU swap. Don't quote me on this, but ECU swaps might require new key coding and all that wonderful stuff.

That engine might be from a W124, those might have had air sensors. I'm not the most computer savvy so someone who is more experienced with ECU's should chime in here.

nelbur

What I see looks like my '97 NA engine. I assume you removed the cross over, and the part of the intake with the butterfly valve that the EGR attaches to. The butterfly valve was just part of the EGR function test and may have been unique to the '97. The '96 had the same engine but had a less complicated EGR. Hook the breather back up or it will suck dirty air into your intake manifold. The '97 did not have a MAF. It had an air temp sensor just ahead of the EGR. I believe your '99 had a MAF. The EGR delete for the '99 was done electrically but on a '97 the EGR tube was removed, the exhaust plugged, and an air filter used to feed clean air instead of exhaust. It seems strange that the parts from the '99 were not just bolted back onto the new engine.