300SD Q's

[mcamara]

I recently purchased a 1983 300SD. What a tank. Love the steering wheel and the comfy seats. Can you tell this is my first MB?

Anywho, had a few questions. I'm new at this so please bear with me. If I should break this up, let me know and I'll resubmit in a "per problem" format.

1. Blue smoke. Possible causes. Is it normal?

2. Sometimes it seems sluggish. Warm or cold.

3. Oil consumption. I'm used to a Toyota Celica.

4. Warmup before driving. Do diesels need to reach 80 before driving off?

TIA for all the tips. Love the website.

[Mr. BILL]

Welcome to the German Yact Club! I'm not a tech but have some history and have gained info reading this forum.

Answers: 1,2&3: Did you have a compression check done on this car? It sounds like you could have a problen with "blow by". #4: I don't think so, a couple of minutes when cold outside should do it. Just take it easy until the temp comes up.

In any event, do a search on your topics and you'll find alot of useful info. The people here are great! I've learned alot and saved twice as much$$$.

[mcamara]

Thanks for the info. This is a great site.
I have not had a compression test done yet but I plan to. It starts easily but I do give it three pumps of the accelerator on cold mornings. How much do these tests cost in your experience?

[rickjordan]

German Yacht Club, I like that. Anyways, mcamra whe you say blue smoke is this on initial start-up or all the time. My '80 300SD lets out a puff of smoke on start up then will see some faint blue smoke, but only until the engine is all warmed up. I will second the taking it slow until the engine is warmed up then you can get on it.
Of course welcome to the best MB web site, where the info. is endless and priceless. Don't forget if you are a DIYer, you can buy parts through the "partsshop".

[mcamara]

There is more smoke in general at startup when it is cold. Black, blue, you name it. After warmup it is not as bad. I notice it most at night because it is more visible when illuminated by other cars headlights. I also notice it when I am sitting at a stoplight during the day. Faint blue smoke wafting past my window.

A thorough "tune up" should reduce the smoking
1-compression test (2 hrs, $100?), while the injectors are out have them rebuilt BY A PRO DIESEL SHOP, not some mechanic who might know, costs $35 each, test glow plugs at same time (or buy rebuilt Bosch injectors outright)
2-Dump a can of Power Service fuel conditioner or equivalent in the tank, improves fuel and cleans engine (available at Wal-Mart, $4.50 or so)
3-air filter and fuel filters (2)
4-valve adjustment (2hrs, $100)
5-adjust linkages for transmission and throttle/lubricate
6-adjust idle and pump settings, a good diesel mechanic can do it

It will cost a few hundred to complete all this but in the end your car will be cleaner burning and get more economy/power. Be sure you chose a good mechanic, it can make all the difference! These items should address the sluggish problem and smoking a little. Sometimes you'll swear they replaced the engine, if the maintenace was lacking from the PO. I have zero oil consumption on my 500000 mile car, and would not accept any if it did. Is it leaking anywhere? I had to replace four or five seals and gaskets lately, common for an engine with blow by (diesels in general that is). Alot of people say a quart per 1000 miles is fine, I would consider this to be the maximum it should use, anymore and the engine has real problems (leaks or rebuild in order)
Because it is an older engine and turbo charged, a block heater is recommended (if under 40F) and two minutes of idling before driving. Of course drive it gently untill ALL the fluids are warm (not just the temp guage reading). Synthetic oil will make a large difference on cold starts too, I use it and it improves my cars cold starting ability be 20 degrees F if not more. Don't forget to let it idle a minute after extended drives or a hard run (which is apparently the only way most people drive em) to let the turbo spin down and cool.
Greg

[mcamara]

Thanks! I will look into the "tune-up". There is a small leak on some kind of contraption at the bottom front of the engine. It looks like an oil pan type thing with a hose running down to it. The leak/wetspot is where the hose connects to it. Other than that it appears dry. By the way,
presently there is Castrol 20w50 in this engine. Could this just be breaking down quickly and causing the smoke? It is rated as SJ which, as I understand it, is not a diesel rating.

I have been letting it warm up for about 5 minutes before driving and then taking it easy until it gets up to 80c. I'm not a lead foot type. My buddy is a mechanic and chastises me if I am abusive towards vehicles. Unfortunately he has no diesel or MB knowledge. He does have lots of tools though!

Thanks again to all in the "German Yacht Club". I have another question but will re-post to keep the thread clean.

Matt

[Edited by mcamara on 02-07-2001 at 08:22 PM]

Greg,
You are my hero! The guys at work make fun of me 'cause I have five cars (all running) and two boats for two adults. Unless you have a whole herd of children, there is no way I can compete! Keep up the good work and give me a call if you need another car!

[Larry Delor]

Hello mcamara, and welcome. I read in one of your posts, that you pump the pedal two or three times in the morning before you start it....You do not have to do this, as you have no carburetor. The gadget that you are describing sounds like the drain tube that connects to the bottom of the airfilter housing. There is a rubber seal there, it may be leaking. I am not sure, but the tubing also may be a two piece tubing, (on a W123 it is) and there may be a small chance that it has come apart..(not likely though).
Always use OEM filters, and every now and then blow off the dust on the freeway, to air things out a bit.
Once you've done a search here on different issues, (like oil, and antifreeze, points of lubrication) you will know alot more than you do now, and enjoy your yacht even more!
-Larry

['79 Super Turtle]

Larry, I also have a 300SD, and my owner's manual states to pump the accelerator pedal 3 times, and then to hold the pedal to the floor for proper starting when it is really cold. I wonder why the owners manual would suggest that? It works for me.

[rickjordan]

From the owner's manual on my 300SD, page 37, "at ambient temp. below 32F and with the engine cold, completely depress accelerator while starting. Actuate starter until the engine fires regularly and engine speed rises. Then ease off the accelerator slowly. Cranking times of up to one minute will not do any harm to the starter. At ambient temps. of less than -4F, depress the accelerator three times prior to cranking."
Just as a side note. I can't believe it's ok to crank the starter for up to 1 minute. Every gas car I have owned has always said not to crank for more than 15 seconds at a time for fear of over heating the starter. These have to be some seriously strong starters to handle cranking a diesel for 1 minute. Over-engineering, you got to love it.

[be459]

At below 32F, a drop of water on the starter may become ice right the way. I think cranking time of up to one minute should be okay; you just warm up the starter. If you keep cranking, the battery possibly dies first before the starter. I may be wrong. I have never had a chance to start a car below freezing. The weather is just too warm here in Southern California.

David

[Jim H]

While a 1 minute cranking DOES require a serious starter, have you looked at the starter on your diesel?

I'm impressed!

BCingU, Jim

[mcamara]

It starts fine. I started to run the battery down before I read the Owner's Manual. Now I have no problems. I have never cranked for a whole minute at a time. It will startup immediately though it may die within a couple of seconds. At that point I crank it without pumping the accelerator as I figure there is probably enough fuel in the right places.
Thanks for replying.

[pgasch]

My '87 TD starts on cold mornings and dies after a couple of seconds unless I crank the starter for 15-20 seconds.

The glow plugs continue to heat up the combustion chamber as long as key is in the "crank" position. This helps warm engine up to idle smoothly.

Bosch starters have very good drives which operate well when the flywheel turns faster than the starter is turning. I believe they call them "underrunning" drives.