Looking for advice on my new 83' 240D
 

Well, I just picked up an 83' 240D with an automatic trans. and am looking for a little advice from the experienced Merc. Diesel tinkerers on this site. The car has 190,000 miles on it, and appears to be in very good condition. Very little rust on the body and none on the undercarraige. I have driven the car a total of about 70 miles and it seems to run quite well, though I have very little experience with Mercedes diesels. I own a 98' VW TDI as well, so my plan for the Merc. is to primarily use it in the summer, especially when the VW is laid up for service.

This is what I know about the car so far:

-Engine starts a bit rough when cold, but fires right up when warm without glow plug cycling. The engine will turn over and start to run after briefly turning with the starter, but then it generally dies. I have been starting it with the idle adjuster turned all the way to the left (high idle), and then turning it to the right as the engine warms. Generally I need to turn it over 2 0r 3 times and tap the accelerator a couple times before it will begin to run smooth. Within 30-45 seconds of running, it begins to idle smooth with a little injector nailing (this is the occasional metallic slap, correct?) which goes away as the engine warms.

-No oil in the air filter tray so I suspect the engine is pretty tight with decent compression. IS this a reasonable assumption?

-According to the previous owners, the engine uses little to no oil. By my inspection, there are no oil leaks. The engine seems quite clean and it leaves no drips. SInce I have owned it, the oil level has not dropped.

-The oil pressure gauge pegs at 3 as soon as the engine starts, and drops to about two in gear at a stop, but then goes right back to 3 as soon as I tap the accelerator.

-The car seems to perform quite well. It accelerates quite slowly in the low range, but once it is going it accelerates quite well. I've had it up to about 60mph on country roads and it seems like it will go considerably faster. It climbs hills without decellerating much.

-The car smokes a bit at startup, but once it warms it does not smoke at all at idle, and under hard acceleration it does not appear to be smoking, but the exhaust pipe angles down like my TDI's, so it is difficult to tell.

-The vacuum system is working fine, and the engine shuts right off.

It seems that the only problem with the engine is the rough cold starts, and my hope is that this is not a result of poor compression. My plan for initial maintenance and trouble shooting is to change the oil, oil filter and all fuel filters, adjust the valves per the Mercedes source tuning manual, and replace the glow plugs and relay with a longer glow relay. Is there anything else I should do right away?

In terms of starting the car, should it start right up after briefly cranking and run without tapping the accelerator? Should I generally start it with the idle control adjusted to high idle?

I plan to use Rotella T non-synthetic crankcase oil in the engine. WHat do other people use? How much does the crankcase in the four cylinder hold?

Thanks in advance for any responses. I know I will be spending some time on this forum.

Sounds like you found a good one and sounds like your maintenance plan is good.

Valve adjustment might help the rough idle at startup. That could also be a weak or burned out glow plug. You can disconnect the glow plug harness at the relay and ohm out each plug. Should be less than 1 ohm cold on each plug. Really no need to replace glow plugs unless one is bad. Really though, a little stumble on cold startups is par for the course.

You can make a minor wiring change to enable afterglow. Do a search on the words: "purple wire" for details.

15W40 is fine for the summer, but you might need want to re-think that for the Yankeeland winters unless it is garaged.

Check the fuel primer pump for leakage. You might want to update that to the new style.

Welcome to MercedesShop.

First hope you will enjoy your new aquisition. Suspect your problems are relatively minor. Rather than changing to longer glow relay etc just check your current glow plugs as you may just have a bad one in there and as winter driving is not contemplated they usually start and run fine with the normal system working properly. At least my 82 does. Find it is really helpful to use the high idle setting to start on with both my 240s. The next or first thing is to check your valve settings as you mentioned before trying to set up idle a little. But again if you find a bad plug or valves really out of spec. idle adjustment may not even be required. A can of diesel purge would not hurt either in my opinion in fact may be helpful. The general state of the air filter may indicate if the last owner cared at all about car. Anyways I really enjoy my two when i get time. :) Edit: sorry for the partial duplication pelang as I was typing a response while you were posting I guess.

Welcome to the best source for info you are likely to find. Great folks here, some smart-alec, some not.
Your plan of attack sounds pretty good, and the advice you received was spot on. Only one important thing to note, and while my tongue is slightly in cheek, this still holds true:
'Merc' = Mercury :eek:
'Benz' or MB = Mercedes :)
We're anal about that kind of thing... :cool:

The smoke on startup may mean you need valve seals.... cost almost nothing....all labor...
Do you do your own labor on your cars ?

Thanks for the advice gentlemen. I will break out the multimeter and check the glowplugs, and then do the valve adjustment. I'm real excited about this car, as it seems to be in very good shape, and is quite a pleasure to drive. A guy here in VT brought it up from Texas a couple years ago, and it hasn't been driven in the winters up here at all. I plan to keep it that way and just use it in the summer, so 15W40 should do it.

Barry,
The previous owners have been using biodiesel and reported dramatically improved performance, so I'm going to hold off on the diesel purge for now, but I do plan on doing it soon. The air filter looks like it is in good shape and relatively new. Absolutely no oil on it or in the tray, and I was very happy to see that when I inspected it before purchase.

JimmyL,
Thanks for the info regarding the proper terminology. I guess now that I am a MB owner I need to keep the lingo straight.

Leathermang,
One of the things that attracted me to this car is its "workability". I do a good bit of work on my TDI like general maintenance, but leave much of the major stuff to the pros. I did install an SVO conversion in the VW 2 years ago, and plan on doing the same to the Benz. I'm also going to experiment a bit with some Kero. WVO blends considering the price of diesel and the amount of WVO I have laying around these days. I plan to do as much of wrenching on the Benz as possible myself, so enlighten me as to where I can learn more about the valve seals.


One more thing: How much oil does the crankcase in the 240D hold? And, are Mercedes the official car of Texas or something?

Mine doesn't have an oil cooler and it takes exactly 6 quarts to the top mark. Yours will probably take 6.5 or so. I'm sure somebody will chime in with the exact figure.

Legend has it that these things like to maintain a level halfway between the marks, although none of mine have ever acted that way. Point is though, that you might be chasing your tail if you try to maintain it on the top mark.

Speaking of oil changes, let us know what brand of oil filter you plan on using. Hint: if it's marked "Made in India" or "Hecho in Mexico", that would be the wrong answer.

Interesting that you ask about the oil filter type. The PO left an oil filter in the trunk and it says Made In India on it. My plan is to get a Bosch or Mann if possible. I saw a photo on an SVO forum of a filter (perma cool I believe) that was made in India, and when the guy cut it apart, the filter media was lint and mouse bedding. I have made it a rule to only use good quality filters ever since seeing that photo. I suspect that the one in the car now is made in india, and that the oil is not diesel rated. Hence an immediate oil and filter change.

Hee Hee, How did I know that??

There was a big thread here a while back about the cotton gin floor sweepings in the oil filters, but it turned into a brawl so it got deleted. Bottom line was, most all brands including the premiums had junk in the bypass section. Fram filters made in Turkey had clean cotton thread in the bypass, so I stocked up on those. Some of the Frams are Mexico though and those are worse than junk. A lot of members settled on Wix filters. The Wix is all pleated paper, without a bypass section. No easy choices on oil filters anymore.

I did not follow that filter thread much because I could not figure out what the problem with having cotton ( and a few twigs ) in there was... When I asked what people would suggest as proper filler I don't think anyone responded... So I did not even realize it was deleted...
There was a good post in there by Randy about a site which seemed to do a good job of comparing filters... wonder if that information is lost ?
A search for ' skinnerbox' will bring up the online engine manual for how to replace the valve stem seals.

Welcome
 

Welcome to the ‘elite’ group of 240D owners and welcome to the forum. I got my first MB (’81 240D) a couple of months ago. I love this car!

The people on the forum can be VERY helpful. I like to lurk around and learn as much as I can and post a question here or there. To keep some of the folks off your back, be sure to search before posting a question. :rolleyes2

Other than that enjoy your new toy! :D

Was this vehicle purchased locally? If so, I would double check for rust in the undercarriage. The factory coating makes it especially tough to see at first. As you probably already know, rust is the nemesis of old cars in the northeast. Tap around with a rubber mallet, and if you find a soft spot, do a search here on POR-15. Welcome!

See post #6...

Do A Search
 

"To keep some of the folks off your back"

That is not the reason to do a search.... for most important questions many people and many ideas are included in the already existing threads...

And EVEN IF everyone were willing to retype everything they had said in the past about a given subject you would have to wait around until everyone stopped by the forum again after you asked....... and some great answers are in the archives from people who have died or sold their Mercedes and no longer stop by .....

NOT LOGICAL. NOT EFFICIENT.

Just an Update on my maintenace schedule
 

Well, I've owned the car for just over a year now so I thought I would update for anyone who is interested. Last summer (I garaged the car for the winter in Nov.) I just did oil changes every 2500 miles, changed the air filter twice and did a valve adjustment. The valves were close to spec. so I suspect it had been done withing 10,000 miles. I slso had the dealer do an allignment which was successful. I put on about 9,000 miles last summer with no major issues.

Since April 15th I have:

-Installed SVO conversion detailed in a thread entitled "83 240D SVO Conversion".

-Had dealer do engine and transmission mounts, transmission service, Valve Stem Seals, header pipe, and glow plugs. I tried to do the glow plugs but could not get them out and did not want to strip them. Dealer tech struggled as well but did get them out. I also replaced all the fuel filters, and the air filter.

On the list for this summer is:

-Water pump and engine belts, power steering filter and fluid, brake fluid flush, and coolant flush. I'm still getting a clunk/rubbing/vibration at high speeds after 45+minutes of driving which I believe is the passenger rear half axle. I may replace this as well with a reman. part. The boot looks ok but fuel was leaking from the filler vent (hose had fallen off) beneath the tank and out the body onto the boot, so is probably a good idea to change half axle.

- I'm working on a leak which I think is the rear window seal. I took apart both passenger side doors, and don't think water is getting in there. I will also replace the outer window seals. Anyone have a good technique for this?

- I replaced the passenger window switch as the front window did not work. Tried to repair the switch but was too far gone.

-Replaced oil filler cap to keep valve cover clean.

Long term projects include:

-Front and rear suspension, Oil Coooler lines, transmission cooler lines, and hood pad. Minor rust on the rear around tail lights.

Thanks for all the great knowledge on this site. I'll continue to keep you all posted as I slowly restore this incredible vehicle. CHeers!