300TD Loss of power - PeachParts Mercedes-Benz Forum

#1 03-10-2003, 04:33 PM

I have a problem with my new used 300TD. After intial acceleration to 40 mph I look forward to the turbo to get me to the 60 mph to 80 mph. I used to have a smooth transition. Now when I give it the gas it needs to get to 60 mph I get a loss of power and big black smoke clouds out of the exhaust. I am at a loss as to what this could be. This is the first Diesel I have owned and need some pointers on it general care as well.

P.E.Haiges · #2 03-10-2003, 05:08 PM

Skemper,

Usually a loss of of power in a Diesel is not enough fuel getting into the cylinders from plugged fuel filters. But you wouldn't get any black smoke if filters were plugged.

It sounds like the Turbo is not working and you are getting a too rich mixture because the engine is expecting more air to be pushed into the cylinders by the turbo. There is also control circuitry that varies the amount of fuel delivered by the injection pump and that could be malfunctioning.

See if you can take off the intake air plenum from the air cleaner to the turbo and see if the turbo spin freely. If it doesn't spin freely, that is your problem. There are also vacuum/pressure lines from the intake manifold thru a electrical box and to the injection pump. Make sure these lines are not plugged or leaking.

P E H

leathermang · #3 03-10-2003, 06:19 PM

Welcome to the forum... We have a great search engine... faster for help sometimes ....

http://www.peachparts.com/shopforum/search.php?action=showresults&searchid=375340&sortby=lastpost&sortorder=descending

benchracer · #4 03-11-2003, 03:05 AM

Skemper, when you mention 300TD, you do mean it's the station wagon right? A lot of new members mistake that TD designation as meaning turbo Diesel. Just want to clarify that.
I have a 300TD also, which I've owned for a couple of years now and have gained some valuable experience.

From what you're describing, it sounds as if your car is a lost cause. Now I hate to be an alarmist, but I really think you were taken by whomever sold this thing to you. Continue to drive this car and you risk an explosion or worse - I mean, it really sounds dangerous to me! These wagons were never really meant to go into production anyway. They were really designed as a joke I think, by Mercedes and the normal quality engineering was ignored because they never intended these things to be driven! I don't know how many made it onto public roads but for God's sake man, for your own peace of mind and your family's safety it's probably best to just give up and go buy a nice 300D sedan. They're much simpler and I'll even help you look for one. Anyway, the wagon doesn't handle very well even when it's in great condition. I don't think you've made a good choice at all. Gosh, I wish I had known you were looking for a new car, any number of people on this forum would have been more than happy to help you look for a nice car.

Meanwhile, just so you can forget about your completely negative experience with this car, I'll be a good guy and take it off your hands. Don't worry, I won't charge you anything. You've already been taken advantage of enough! Just email me when you're ready for me to pick it up. If you're not going to be home, just give me your address and leave the keys on top of the right-rear tire and I'll take care of the rest.

Good luck with everything, Skemper!

leathermang · #5 03-11-2003, 06:24 AM

Benchracer, Such a BIG HEARTED GUY YOU ARE !!!!

#6 03-11-2003, 08:37 AM

Thanks. I take a look at the site

Carrameow · #7 03-11-2003, 09:13 AM

By the way, is it Automatic Transmission?
I t probably is. Is your transmission shift point correctly adjusted? At loss of power do the revolutions (RPM) shoot up suddenly?
What happens when you floor it?(High acceleration)
How does it act at low acceleration?
How does it start on a really cold day?
What is your oil consumption?

I bought my last 300D at a junkyard and restored it. When I bought the car it had no power but when I floored it, it really had some burst. I knew the engine was in great condition right away.
I monkeyed with fuel filters, the tank filter, but in the end it came back to brand new condition after I adjusted the auto transmission shift linkage.

Keep the faith. In my early days I used cheap non OEM rings when I rebuilt my first engine. I didnt rebore either. The engine used a quart of oil every 3 days. But it still had power.

__________________
1983 240D 240K owner rebuilt engine
1985 300TD 250K owner rebuilt engine
http://mywebpages.comcast.net/changrich/BENZ.html

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03-11-2003 07:13 AM

#8 03-11-2003, 01:22 PM

I too suggest you use the search function. There is a lot of good info in previous posts on the vacuum system, the turbo system and its controls, valves and safety cutoffs, the ALDA, etc. , that you should find and study to get the big picture as to how the fuel/turbo syatem works and how to maintain and trouble shoot it. Eventually you will see that there is a progression of things to do to check elements of the system before you have to bring in tech reinforcements. Also, my own experience is that these cars are so old now that we get old-age problems that shop techs sometimes have trouble figuring out because they are busy trying to keep up with new models for which owners are willing to pay big repair bills. This forum is the absolute best place for you to start. As you narrow down the problem, come back on the forum with more specific questions and you will be amazed at the help you will get. ( with the 300TD wagon - wait till you get to the self leveling system issue - tons of invaluable help on this site for that) Good luck!

benchracer · #9 03-11-2003, 10:56 PM

But seriously Skemper... I don't have an answer for you on this one. I'd be curious to know the outcome as we all learn a great deal from one-another here.

Good Luck and keep us posted.

mercedesmatt · #10 03-12-2003, 12:35 AM

a few things to check. first, if you havent done so, replace the fuel filters, and air filter. while you have the air filter out, check the small 3/8" rubber hose, about a foot long, that is on the turbo, runs to the waste gate, look it over very carefully for holes, cracks, etc. give that baby a few sharp tugs, then just go ahead and replace it since it maybe clogged with gunk!!!

3/8 fuel line will work ok, oil resistant hose is better. then check the hose that runs from the back of the intake manifold, to the soleniod on the firewall, and then to the aneroid valve on the fuel pump, small, clear or white plastic line, trace it all out and look it over very closely like above. ill sleep on this tonite, im beat now, if i think of more ill post tomorrow!! good luck!!
matt

rderton · #11 03-12-2003, 12:50 AM

skemper,
I had a similar problem last week with my 84. The hose mercedesmatt refered to was loose. I tightened it up and the problem went away. Find the alternator and go back about a foot and you should see it.

Carrameow · #12 03-12-2003, 07:30 AM

Everyday someone passes me in a Maxima or shiny SUV its good to know you guys are out there...my 240D may look different and be sluggish but hopefully the time Im putting into restoring its worthit and we will grow old together...

autozen · #13 03-12-2003, 11:31 PM

skemper,

#1 You need to provide either a VIN# or a description of the vehicle you have so we can accurately diagnose your problem. There are people here who can help you, but we need to know what you are driving.

#2 I don't know what benchracer is smoking, but it would be civil of him to share it. The 123 and 124 model wagons are incredibly well designed automobiles. They are very functional and safe. Volvo only beats them in the design of the rear seat headrests. MB rear seat headrests are a pain to deal with when folding the rear seats while the Volvo headrests are not.

Pete

autozen · #14 03-12-2003, 11:49 PM

Carrameouw,

Be proud of that 83 240D. That was one of the best cars made for the money. THey finally got it right and then discountinued it. The 83 had velour carpeting, electric right hand mirror, and delayed interior light. I'm not saying it was a 380 SEL, but for value it couldn't be beat. In my opinion, the 83 240D should go down in history as a magnificent production.

Peter

leathermang · #15 03-13-2003, 04:54 PM

Autozen, Benchracer was kidding in that first post.... I recognized it because I have done the same thing...and the next time he said " But seriously Skemper " ...

Sometimes the effect of a humorous post is lost if you have to put the little smilies on it....But it can get one in trouble if others do not read it as meant to entertain.....