New to MB's & Diesels....help
 

Hello to all and many compliments on an outstanding forum. I just purchased an '87 300 SDL with 220,000 miles. It was a one owner car up until 190,000 and I have all the dealer & maint. papers up to then. The car is very solid and clean inside and out but I do have a few concerns mechanically. It has a terrible cold start. It will fire right away but run very rough and stall after 5 or so seconds. It will do this 4 or 5 times (until it gets a little warmed up?) before it will stay running and then it runs a bit rough until fully warmed up. It doesn't have any knocks or hesitation. I'm noticing a lot of black smoke on start up and also during acceleration and I am VERY disapointed with low and mid-range acceleration. It is almost embarrasing to drive in the city. I can't percieve any feel of turbo boost. I'm going to start with replacing the air (very dirty) and fuel filters and any suggestions would be greatly appreciated. The trap ox. was removed by the dealer. I would also appreciate the name of an honest repair man (for the major stuff) in the metro detroit area. Thanks to all in advance!

Keith

Easy things first
 

Replace ALL filters first, easy and cheap. Then check your records to see when the last valve adjustment was done. There could be other things causing this problem. Employ the "KISS" principal, Keep It Super Simple.

There is no valve adjustment required on these cars. I agree, replace the filters first. Before a cold start, make sure you let your glow plugs do their job. They don't stop glowing as soon as the light goes out, they keep going for about 30 seconds and if you let them glow that long I'm sure your cold idle will be better, assuming all your glow plugs work. If you feel no turbo boost, check for clogging in the plastic vacuum line going to your injection pump. If it's clogged it will prevent the turbo from kicking in.

603's will skip a bit on a cold morning that is normal. But it sounds like yours is skipping really badly.

It sounds almost like you might have a weak glow plug.

As to the being slow off the line I am not sure I have not had to deal with that problem yet. Maybe a turn of the ALDA would help.

Change the filters before you do anything though, a very dirty air filter will cause black smoke.

buying a car nobody loved.(at least in the last while).
 

The air filter is the first place I look as just trying to establish if past owner cared the slightest about maintenance or car at all. Unfortunatly most my aquisitions have had filthy air cleaners. Since this is absolutly the minumin effort to check and replace on a diesel and the results so common and generally known if dirty when i find this it means I will have to check everything of a maintenance nature out sooner rather than after awhile when I get time. Your case sounds simular. You almost know now that the other more involved things have probably not been done either. Some people feel a diesel needs nothing other than fuel filter changes no matter how long they drive it if even that. One thing to check pretty quickly is timing chain condition if the records you have show not changed at recommended interval as if it decides to part company the least of your worries will be the items mentioned in your post. The timing chain will still need checked though as if car has not had it's regular oil changes the chain is the most wear sensitive component with dirty oil inside the block. Think your engine is touchy about overheating as well so check and replace all hoses in cooling system that are even a little suspect. Your other items are most likely modest in comparison. Check belt or belts very carefully as well. Make sure car does not have green antifreeze, Look and see if brake fluid clean or dark. All will give indications and in some ways may make your other complaints easier to rectify as they will almost be just general maintenance items as well. This site will easily get you up to speed if you read the posts pertaining to your type engine. :) If I purchased a 603 type engine would not want to loose it just from lack of general maintenance. We have never met but there are one or two gentlemen on this forum that service mercedes independently in the detroit area and it might be cost effective to let them have a look if you either do not feel up to it or have the time. From their help freely given on this site plus the generally balanced involvement they display I do not need a recomendation as it is about as good as it gets. They will take the systamatic approach to your engine that you may lack plus the equipment or experience to do. Their experience and integrity might also save you a bundle down the road. Wish there was somebody like that in my area but there just is not. :) Just a few thoughts and my opinions. Oh yes, welcome to the forum it's by far the best one I have had the pleasure of experiencing by far. How they tollerate me is beyond my comprehension. :rolleyes:

Welcome to the forum.

If you are not familiar with this engine, or diesels in general, it would be to your distinct advantage to contact WHunter, a professional mechanic, who is also a member of this forum. He works near you in a shop in the Detroit area.

I'm quite sure that the time invested with Mr. Hunter will pay you back many times in starting you off on the right track with understanding this new vehicle.

You can contact him via a private message through this forum to make arrangements.

Good advice listed above!

Congrats on your purchase and welcome to the forum! You need to get all of the regular maintenance items up to date. Replace all filters, check glow plugs, change all fluids, clean pressure line and banjo bolt from intake manifold to injection pump. Once all of that is done, it's time for a nice Italian tune-up to blow out the years of build-up from lack of maintenance and lazy driving.

Thanks!
 

I can't thank you all enough for the help you've given me so fast. I just sent a private message to Whunter requesting his help and hopefully he will get me started on the right path to trouble free enjoyment of this fine automobile.

Thanks again to all,

Keith

way to go.
 

Good move on your part. Once you are sure all the things are checked out pertaining to this engine you will not be in a situation of winning the battle over a little rough start. But totally losing the war a few months down the road through major failure caused from a relatively small item. Who really knows? Possibly many of these small items may check out well. On the otherhand if something is getting pretty bad you will have nipped it in the bud. Really dislike the posts where a timing chain has let go at 70 mph. Or the engine has overheated. Or a guy has spent a lot of money without even doing a compression check when the need is indicated. Subconciously he knows better but just does not own a diesel compression gauge. It would be easier if I had less compassion for people. My guess is hunter will suggest to you how not to abuse this engine and he seems like an upfront friendly type of person as well. Make sure you take in all the past service records with the car as they will also help. Kind of redundant really as he is going to request them anyways. Still suggest you read all the post on the 603 engine when you get time as a little understanding can go a long ways. Let us know what was required on the 603 engine to make it solid again as most of us look for information about this engine model. There are not enough of this model out there to meet future demand I suspect once it really starts. Know I am considering one myself. Again welcome to the site. :)