w210 e300
 

Hi guys, Im new to the forum, just brought my first mercedes today, a 98 w210 e300 Avantgarde TD. But its a bit poorly!! acceleration is very slow, and it doesn't like to go above 80 mph!!! any ideas whats wrong with it? I was thinking the MAF sensor, hopefully its not a transmission problem???

I'm pretty sure that the MAF will throw a code and illuminate the malfunction indicator lamp. If you're not at redline on the tach, the transmission isn't the problem.

First check for any pending codes. If you have none, the first thing that I would do is to change the fuel filters. Be sure to get a new O-ring for the prefilter and install it; the new prefilter will not come with it installed. The second thing that I would do is to ensure that you are developing boost.

Additionally, look for any fuel leaks at the clear plastic fuel lines and on top of the IP at the delivery valves. Is possible that under higher fuel demand it is sucking some air. The pre-filter oring would be the usual culprit in that event.

The MAF fault on the 606 turbo is usually pretty obvious in my expirience. Should activate the CEL, there is no turbo boost and it is difficult to pull more than 3k RPM's in any gear.

*edit* If as Matt suggested you are not developing boost, the transducer at the EGR is the same as is used at the turbo. The two can be swapped to see if that is the problem.

How many miles and do u have service history? If it is not going over 80 MPH its starving for fuel....

Get all the filters changed and be sure to add diesel purge and hell go 50/50 Diesel/Kerosene.

Then drive it if you hit 120 to 130 mph your ok or crazy ....

Okay then, I'll do that, Its 172k, part service history. none recent, when i checked the oil tho it was not really bitty, like it had been serviced recently. I checked the turbo today and it was just about warm after an hours driving, but im guessing that if its starved of fuel like you guys say its not going to get hot anyway. I don't know where the EGR valve, is on the engine, but then again I havent looked round throughly...

Two more Questions tho. What make and model is the turbo charger, and also where is the best place to plumb in a boost gauge?

I have a Ku Klux Klan Turbo. You will see the triangle with the KKK inside the triangle. One K on top and 2 below. IMO, the best place for a boost gauge is AFTER the intercooler. After all, you want to see what the engine is getting. So, on your manifold, it splits into 6 parts. Try tapping BEFORE the split.

I wouldn't think so since it gets exhaust gas which is plenty hot. I have had the rear section of a Garret T3/T4 glow in the dark along with the manifold after a hot lap. The front was hot but not glowing.

The EGR valve is just below the 6 way split. See post here. Also, if you go remove the manifold, I'd take the GPs out also and anti-seize them.

If you are suspecting injectors, I'd forget the snake oil like Diesel Purge or what I call Double Penetration. Take the injectors out and have them tested. That way you will KNOW for sure if it is good. At 172K, I suspect at least one of them is crudded up. I had them out at 100K and 5 were good while one was dirty and needed to be disassembled, cleaned and retested. Total bill for that part of the work? $70. You could spend $200 on DP and not know for sure if the injectors are bad or good. Though you would have a SWAG.

Check the turbo. Take out the front hose and see if you can spin the blades freely. There should be no noticeable drag and you should not be able to wiggle the shaft back and forth. Look around the exhaust manifold all the way to the turbo and see if it is sooty at the joints.

As a last resort, you might disconnect the down pipe and run it BRIEFLY to see if the cat is clogged.

Thats in/out there should be none of, some side/side is normal.

Sorry, I was thinking of something else that goes back and forth or in and out. :D

Yes, A LITTLE side to side is normal.

The transducer controlling boost is down by the right (pass) side motor mount. You'll see it from below; prob have to remove the belly pan first.

The transducer controlling the EGR valve is mounted on the firewall on the left; the EGR is beneath the IM and the trasducer is directly adjacent to it.

Do not blend 50/50 diesel/kerosene; is not an approved blend for your engine and the IFI computer won't like it. If you need al ower gel point use D1 instead of D2.

I'd leave your inj's alone until you know if you have boost (or fuel leaks) first. Then I'd test your MAF. Search MAF Test Procedures.

It's not getting enough fuel, air, boost or combination thereof.

You dont have a K&N air filter do you?

Spray a little electronic cleaner on the MAF. You take out the sensor part and clean the housing with brake cleaner and use the electronic cleaner on the sensor part. Not a direct spray but a gentle mist.

I haven't had the chance to check the turbo charger yet, But im planning on upgrading the turbo charger at some point anyway. I know that its going to be a bit of work to get one on, but I want a VNT charger, I have an actuator controller VNT2556V in my garage from a BMW 530d, but it doesn't look like I can get it to fit in the engine bay even if i get an adapter plate made up. So does anybody know any VNT turbos that are actuator controlledbut have a flange to fit the exhaust manifold on this engine?

My first suspect would be the MAF. Isopropyl alcohol on the element to clean. Don't use carb cleaner.

Don't touch the element.

You should be doing 0-60 in no more than 9 seconds. Can you hear the turbo spooling when accelerating?

Second port of call is to swap the two vacuum actuators over. One does the EGR, the other does the turbo. They look like this:

http://farm1.static.flickr.com/46/14...b3d91fa23d.jpg

(the black cylinder and pipes on the left, not the ABS pump). Its a 5 minute job to swap them over, its dead easy, no need to go underneath.

There should also be some small cone filters on the vacuum lines in your engine bay. Check they're all there (they'll be hanging around the tops of the wheel arches. You can see one in this piccie:

http://farm1.static.flickr.com/44/16...731d64c7dd.jpg

(orange filter on the right).

Lastly, and I know its stupid, but check that your accelerator pedal isn't being blocked by the carpet, and that the full range is available at the BOSCH potentiometer in the picture above (get a mate to stomp the accelerator pedal and watch to ensure the pot winds fully).

I drive a RHD car, so I'd imagine that potentiometer is on the other side of your engine bay than mine.

Your flange is unique to that turbo and engine. You will have to make a custom manifold if you can't get anything to fit with an adapter plate.