1985 300d turbo - PeachParts Mercedes-Benz Forum

kaleope · #1 05-12-2010, 11:03 AM

not much experience here, had the car 6 months and I love it. Car would not shut off so we by passed the power door locks and it worked ok. Now it started to not shut down again except for using the kill button under the hood. Brought to the mechanic and had belts & oil changed. Replaced brake booster. Get the car back and it wont go over 40 when floored. Some odd smelling smoke comes out at times, like a fiberglass smell. Other times black smoke at full throttle. Rougher idol than before. I returned the car to the mechanic and he says the turbo is no good. I am reluctant to change it because the car ran ok before. Always slow and not the mileage that everone talks about but ok. I miss the car, any ideas ? (120,000 miles)

1985300d · #2 05-12-2010, 11:30 AM

check for cracked hoses under the hood

drivers side under hood make sure no lines poped off

clean the bolt on the back on the intake that goes to the fuel pump, if its plugged with grime is why it runs bad

change fuel filter, the big 1 and small if you havent yet

adjust valves

when the car is NOT running, remove the air box and all so you can reach into the turbo and see how much movement there is, in and out and side to side

i wouldnt go back to the mechanic, a good mech would have told you what else was wrong before ghe gave it back, or ever test drive it before it was returned

kaleope · #3 05-12-2010, 11:43 AM

thank you will do all of that....I appreciate the help.

1985300d · #4 05-12-2010, 02:49 PM

99% chance removing the valve cover off will pop off some little vac line
get a valve cover gasket to be safe before valve adj
black take the black 3-way ends for temp fix if you must

i would do a diesel purge if you never have

after all that, do the italian tuneup, aka drive it like you stole it
change the oil and filter, wont do any harm if you just did it,
only hurts the funds i guess

make sure you get wot with your foot on the floor, when not running

make sure air filtter is clean

disable the egr, goes from the intake manifold to the exhaust,
plug the line with a bb or screw on both ends, remove the vac line back to the drivers front fender, i think it goes to a 3-way, plug with another screw
in future remove and use a block plate on intake and exhaust, or get rare manifolds that dont have the port cast into them

then take off you intake and clean all the junk out of it, then u pimpin lol

ImBroke · #5 05-12-2010, 02:57 PM

While messing with the brake booster, it's totally possible to have knocked off some vac lines. If it ran fine before, what he did should have NOT broken the car. Always go back to the last thing done during a problem like this. Not go back to him, but what was performed.

vstech · #6 05-12-2010, 03:13 PM

near the booster is a little valve with two clear lines attached to it.
odds are good he broke one of the lines. that line tells the alda how much fuel to feed the motor under boost. start at the metal can on top of the IP, follow that hose to the firewall, then around to the back of the motor, and VERIFY it's not broken anywhere. no hose, no boost. also it could have gunk in it. but if it worked before the booster was changed, and not after, then odds are good it got broken.

kaleope · #7 05-13-2010, 01:14 AM

which I had the manual trans like yours !

cirrusman · #8 05-13-2010, 02:19 AM

This is how you check for the vacuum:
http://dieselgiant.com/mercedesvacuumtroubleshooting.htm
They might've broke a line going to / from the ALDA unit, or it might just be dirty. Here's how to check and clean it:
http://dieselgiant.com/mercedesaldaboostsystemservi.htm
You'll also find pictorials on that website on how to do your valve adjustment and your Dieles purge if you're thinking on doing that too.
Good luck!

t walgamuth · #9 05-13-2010, 05:02 AM

It does sound like the plastic line was broken. It will act like the turbo is not working but it just is not giving more fuel when needed.

I would skip the italian tune up and the diesel purge myself.

snookwhaler · #10 05-13-2010, 01:04 PM

Quote:

Originally Posted by kaleope

I returned the car to the mechanic and he says the turbo is no good. (120,000 miles)

This quote tells me that the mechanic is VERY unfamiliar with these vehicles. I would not take it back there.

As others have said check the vacuum lines on the drivers side. Especially the clear lines associated with the boost and ALDA.