Overhauling a 1984 300SD

I belived my 300SD has finally died. I am thinking of getting the engine overhauled. Any comments pro or con will be greatly appreciated. Also, how much do you think it will cost to get this purring again?

[Elripster]

Are you doing it yourself or paying someone else to do it?

Frank.

[Ken300D]

What's wrong with it?

- won't start?
- no power?
- burns oil?
- broken timing chain?
- bad glow plugs?

Not possible to give much advice unless we get more information.



Ken300D

[P.E.Haiges]

You might be better off to get a rebuilt engine from a competent rebuilder. You will get a better warranty that way. If you can do the R&R yourself, you will save a lot.

P E H

[CHAPP]

Mine was almost dead and I overhauled the head/injectors and installed a new turbo...it runs great now with no vibration, and little smoke. I was smoking so bad traffic was staying away from me. As long as your bottom end is fine...the upper part of the engine can make it run great or cause alot of smoke.

[RSH]

Depending on the condition of the rest of the car and major accessories like a/c, drivetrain (transmission), power options, etc If its excellent I would buy a rebuilt motor, If its more of a daily driver I would find a good used motor because it wouldnt be worth dumping excess money in to it, or maybe look for another car.

[P.E.Haiges]

RSH,

Do you mean a rebuilt engine or used engine?

Most motors run on electricity but none run on Diesel fuel or gasoline.

P E H

As a previous poster asked, what is wrong with the engine? It very well could be that all you need is a top end overhaul. It would be worthwhile to perform a leakdown test to determine the condition of pistons/rings/cylinders.

P.E.,

I get a real charge out of your distaste for referring to an engine as a motor. It always gives me a chuckle.

The reason is that I used to have the same idea, but after the Army, I somehow got past it. I guess I just got tired of fighting it. I now use the words motor and engine interchangably.

Being devils advocate, how about terms such as "Smiths Motor Cars?" Are they only selling electric cars?

Please don't take me wrong on this, I'm not challenging, making fun or disputing your terminology. It's only for light hearted discussion.

I'll talk to you later, I now have to run out and check the oil in my ENGINE.

Have a great day

[P.E.Haiges]

Larry,

I'm glad I can cheer up you day. I know its tough to change with all the terms such as Motor vehicles, Motoring, Motor oil. Motor pool, ETC being used. Perhaps these terms go back to the days when there were electric cars and it might be true in the future when we go to fuel cells or highbrids with electric motors again driving our vehicles.

Since this is a technical forum, I think the correct terminolgy should be used. It would make for better understanding. Here are some more:

I don't turn my engine or car over (the oil would runout and its much too heavy), I crank the eingine with the starter motor.

I don't turn the ignition on or off in a Diesel (because it has no ignition system) I turn on or off the key switch or main switch.

There is no such word as amperage, its current (in amperes or milliamperes).

Power does not flow thru the wires, but current does.

There are more, but that's all I can think of for now.

P E H

[CHAPP]

Some of us might not do English quite as good as you...Austraila and England do it their way, using their own slang. But I do know what you are talking about, sometimes I have to read a thread 2-3 times to understand what is being asked...depends where the person lives.

Thanks to all that replied with hekp for my 300SD. Here's some more info. The ENGINE leaks oil (it could be from the oil plug), the glow plugs don't glow anymore but it will start on warm days, it doesn't have any power, it has alot of vibration.

I am not a mechanic so I will be paying someone else to do the work. I also don't know a lot about diesel engines so all your suggestions have been educational.

I will get the Leakdown test done and then deside what the next step will be.

Thanks, Ed

[kerry]

Now the answer is easier. If your engine requires valve adjustments, get them adjusted if they haven't been done recently. Do the compression and leakdown tests before making a decision. Fixing the oil leak and glowplugs should be relatively minor jobs that wouldn't warrant considering a replacement engine.

Well. it looks like it will cost me between $100 and $200 to have the engine checked. That is to check the glow plug, compression and leakdown test. Once I have that done, then I can make my next desicion. Meanwhile I am keeping my eyes open for another 300SD. I realy like the car and I wouldn't mind having anotherone.

[RG5384]

If your seriously looking for another one, you should probably give it a valiant effort to try to work on these cars yourself. If you learn to do simple jobs yourself, there are quite a few main advantages. One, is you will save a TON of money, almost any shop that sees the three pointed star goes "caching!", next, it is very rewarding and fun to work on these cars yourself. You will not only learn how to work on these exact cars, but take the knowledge and apply it to other things. For example, there are many times you must think creatively to figure out how to get to something, working on a completely differant project you could realize, "this is similar to the time i had to........." From what i've read and my limited knowledge of these cars( i own and 83 300SD) i can give a couple of possible problems with your car. Firstly, a diesel is hard to start without glow plugs. If these arent working, it will make even a nice car seem like a heap of trash. The glow plug system isn't that complicated on this car. It consists of five pencil type glow plugs, and a relay. The relay is located on the left front fender wall, and has an 80 amp fuse. The fuse is held in by two philips head screws, and is located under a plastic snap on cover. Take the fuse out and see if it falls into two peices, if it does, thats why your glow plugs are not working. The next set of troubleshooting is a little bit more involved, but not complicated. If you want to try to troubleshoot it yourself, do a search for "glowplugs" and you'll find more info than you'll ever need.

Next with regaurd to the rough engine, this could be a couple of issues. If it is really rough after it warms up it could be motor mounts, valve adjustments, or faulty injectors. The test for faulty injectors if fairly simple as well, and the motor mounts you can tell just by looking to see if they are collapsed. If the valves are out of wack it will also cause alot of smoke and hard starts as well as low compression. Get it checked like your planning on doing, but just because of these small things doesn't necessarily mean you need a rebuild. Just my .02 cents
Ryan

Hey PEH,

Nothing flows THROUGH the wires, along the outside yes, but not through them.
Since we are splitting hairs