new 240D owner!!! I have some questions about car

I don't know if I should be congratulated or scolded. I just bought an '80 240D that was not really represented well on ebay. Don't get me wrong, the car is nice....just a few concerns:

1) The car has about 8-10 inches of blow-by when cap is taken off. It also "mists" a little bit of oil on top of valve-cover when cap is off....but nothing that a paper towel or two can't clean up without it being a real mess. Is this a sign the engine is worn out or is this normal blow-by?

2) The car has always been in Calif. and has no rust. However, the real window seal leaks just a wee bit. After a hard rain I noticed that there were a few drops in the trunk and that the carpet by the back window was a little damp. I looked at the seal and it is cracked in a bunch of places. I called around and was quoted $150 for the repair. Any tips on repairing the window? Is this normal on these cars?

3) The cruise does not work. But, the car holds vacuum (locks continue to work) after car has not be started for a few days. Any ideas?

4) The AC won't kick on. I think the freon is so low that the compressor won't engage. Has anyone converted their GM style compressor to R134 with any luck? I think I should replace all parts (except probably the evaporator...too hard to change...I would think) if I try to convert over to R134. Any suggestions?

5) I have a diesel leak on the outside of the injector that is closest to the firewall. Upon close inspection it looks like the "braided" lines made out of some type of fabric are soaked in diesel? Do these leak a lot? Easy to replace? Does the injector have a rubber seal or something that might need to be replaced to stop leaking?

6)Brakes squeek when pressing on brake pedal ONLY when car is traveling in reverse? Any ideas?

7)This is the BIG CONCERN that I really need some expert advice on: It is a manual trans car and I noticed that around the trans housing that a few dropplets of oil accumulate there and probably 3 or 4 good size drops hit the ground after I drive the car. The valve cover is not leaking at all.....so is this the rear main seal going bad? Do I need to get this changed righ away or is this nothing to worry about? Everything else under the car is dry except for this area. What do you think it would/should cost to repair? I don't want the clutch to start slipping because it is oil soaked.

Ok, sorry for all the questions....I really appreciate everyones time they give in their replys. I have not serviced the car yet and have some basic questions that would aid me in a few areas of routine maintenance:

1) how many quarts of oil does it take?
2) Type of antifreeze I should use in car?
3) Type of man. tran fluid?
4) Type of power steering fluid?
5) Any fittings that need to be greased or are they all sealed?
6) I have read that the valves should be adjusted every 15k, besides getting the special wrenches is there anything else I should know/do when performing this job? Does anyone use any sealant when putting on a new valve cover gasket?
7) Any tricks to getting system primed once the two fuel filters are changed?

The car is almost perfect on the inside. I mean this thing looks brand new. It has only one small crack in the dash and the seats are like new. The only thing that needs attention as far as the upholstery is some cloth around the door on the driver and passenger side....nothing major though.

Car has 240k on it....not sure if the engine has been rebuilt though. I can do 55 going up a very long 7% grade in third gear and temp gauge does not move much. I think it is a pretty good car....maybe I did ok....maybe I didn't. Your feedback is much appreciated.

mike

[skalie]

Originally posted by mrwith
5) I have a diesel leak on the outside of the injector that is closest to the firewall. Upon close inspection it looks like the "braided" lines made out of some type of fabric are soaked in diesel? Do these leak a lot? Easy to replace? Does the injector have a rubber seal or something that might need to be replaced to stop leaking?

mike

Rubber tube covered in fabric, very cheap, cut to length and replace, simple as that. You have to pull those off to unscrew the injectors, after doing that a more than a few times they need replacement.

I'll leave the rest of your questions to the experts, boy are they going to love this thread.

Richard.

[psfred]

Mike:

Blowby is about normal for this car and milage. If you have high oil consumption, too, you may be looking at a rebuild. The oil "mist" is oil flying off the camshaft -- don't drive one of these with the oil cap off!

Get the real window seal replaced pronto -- there is water everywhere! These seals go bad in about 15 years and leak like crazy. Do the front, too when you get a chance. It's bad too, for sure unless it has been replaced. Water leaks from the windows will eat the floor pans out from the inside.

The cruise control is on a separate vaccuum circuit from the locks. Check all the rubber ends on the vaccuum lines at the servo -- they are probably rock hard or melted and leaking. If that doesn't fix it, it is likely the amplifier, a known weak point. Check the tail lamps, too -- if they are bad, the CC won't work (this is how the amp is swithed -- see other threads on the issue!)

AC is most likely low. 134a works fine, I just did all the cars this summer. Unless I'm mistaken, the seals are all rubber o-rings, which may have crapped out and are easy to replace. The 220D has copper seals! All I did there was recharge, then replace the high pressure line that blew (great fun). Don't over-oil the AC, it doesn't need that much.

Overflow tubes have been covered, except that you will be very disapointed if you use anything except the MB stuff -- nearly anything else I've seen leaks rapidly. They usually last a couple years.

Brakes sqeaking in reverse can be pistons not proplerly aligned in the calipers, but only if the dust shields were left out. Might also be missing some anti-squeal shims. Disk brakes squeal by nature, so if there are aftermarket pads in there, haha. MB OEM pads usually wear faster, but are very quiet.

The rear main seal leak is a problem. MB "spikes" the rope seal in both pan and block, so there is no way to pull it out and pull a new one in, to say nothing of the impossibility of removing the oilpan with the engine in the car. I'd get a drip tray to put under it and wait until you have to get the engine rebuilt -- the crank has to come out to get the new seal in, and you are then going to want new bearings (the old ones are too worn to put back in), and since you have already paid for engine removal and dissasembly, it seems to me rather dull not to go the rest of the way and renew cylinders, etc. Your call.

Oil capacity is 6 or 6.5 quarts, (please use good oil).

Green antifreeze is fine, this engine is all cast iron.

Tranny takes 90 wt oil, so does rear end.

Not tricks to valve adjustment if you've done one, although it is kinda a pain for reasons of limited access.

Valve cover gasket is a "u" shaped rubber one -- it can be re-used several times. When it gets hard or gets little cracks in the bottom sealing surface, replace it.

No sealant, but do wipe the sealing surface of the head down with solvent so that it is completely dry and free of oil. Make sure the seal is dry, too, then fit it on and bang it down hard against the head until it makes a solid thump -- seats the gasket on the valve cover. Sounds strange, but this is MB factory training. If there is oil on the head when the gasket is installed, it will leak.

No grease fittings.

To prime when changing filters: pump, pump, pump, pump, pump that primer pump. If the old one is the red handle unscrew-and-pump type, it usually leaks -- replace it with the new push-it-down-and-it-prings-back type. I usually fill the new filter with fuel (outside holes) -- the pump only puts out a few CC of fuel per stroke and takes several hundred strokes to actaully fill the new filter. Crack the bleed screw if you have one and pump until no more air comes out, or the engine may stall shortly after starting and you will have to pump and crank forever!

Other than the rather sedate acceleration, these are wonderful cars. Unless you paid a big pile of money for it, you did fine.

Peter

About that rear seal leak--I also recently purchased a 240D. It too appears to have a leak from the rear main seal. But upon closer inspection it is leaking around the oil filter stand where it mates to the block. You might want to give it a check.

On the cruise control issue, mine wasn't working either. Before you buy a new amplifier, you may be able to salvage the old one with a soldering iron and a few hours labor. There is a method outlined on the Mercedes Benz Club of America website (www.mbca.org) under the technical section.

Thanks for the replys thus far. I plan to get the rear window fixed VERY soon. The truck and floorboard are not rusty....so I think the car just started to leak.

I am not very happy about the rear seal being such a huge deal to take care of. The engine runs so strong I really don't think I need a rebuild anytime soon. I am concerned about the oil messing up the clutch. Is this a concern? Does anyone have a clue as to how much the seal would cost to have it replaced?

I will replace the fuel lines to the injuectors. But are there seals on the injectors themselves that can leak? A lot of diesel has pooled around the base of the injector by the firewall and ran down the block.

I have looked at other posts since writing this thread and have heard where some people put ATF in the man. tran. So, it is 90 wt...not ATF...right?

I forgot to add one more question to the original thread: This may seem weird, but every pin switch on all four doors work....but only if you slightly depress them with your finger. In other words, if you open the door and do nothing...the interior light/buzzer won't work. But if you slightly push in on the pin switch with your finger, everything works fine. The same is true for opening the rear doors for the rear seat light. Do I have four pin switches that are on the blink or can they be adjusted?

Thanks again for everyone's input.

mike

[psfred]

Mike:

You're correct, it is Type A transmission fluid for the tranny. I read the list too fast....

I don't know if oil will get on the clutch -- I'd suspect not.

There are seals that can leak on the injectors, but I'd get the overflow lines fixed first -- it's not really possible to tell if the injector holder is leaking of the lines do. Check for leaks on the valve cover gasket, too -- if it leaks at the rear it will drip off the bell housing.

The door switches are probably dirty -- work them by had a couple times and see what happens, and try spin the pin some -- cleans the crud off the contats.

Peter

Mike,

You've gotten some very good responses, but I can't stay away from a thread like this. The manual transmissioned 240D's are near and dear to me.

With the engine idling and oil cap off, there will always be a little oil come out. It's hard to describe what is excessive, but it sounds as if yours may be. That alone is not the total indication. Oil consumption plays into this. Once you get a fix on oil consumption you will have a better picture of this. BTW, the engine has probably never been apart. 240,000 is not particularly high mileage on one of these cars that has been properly driven and maintained.

You will certainly want to follow psfred's instructions on the cruise control, but once you've checked all that you may find that there is a problem with the amplifier or some other expensive component.

Changing to R134a certainly CAN work okay, depending upon your climate and how you drive. If you do short hops in a Houston, Texas type climate, it's not gonna cut it. You just lose too much capacity. If you're in a milder climate and don't do short hops, stop light to stop light it can work well for you. You will not have to replace the evaporator. It is best done by removing all connections and flushing thoroughly with refrigeration system flush and compressed air, being careful to remove ALL the flush. As you put everything back together, replace the filter drier and use green o-rings everywhere. Remove the compressor and dump out all the oil you can get out, which may be none. Then put in about 6.5 oz. of Ester Refrigeration system oil. Once the system is back together, pump down with a wet vane pump for 24 hours if possible. You want to get absolutely as much moisture out of the system as possible. Any moisture left behind combines with the refrigerant making an acid that will eat up the system from the inside out.

Your best bet would be to get a stick of the injector bypass hose, cut individual pieces off of it and replace all the lines. Also replace the plug on the back injector.

If the brakes squeak, but still have enough lining that they won't go to metal to metal contact any time soon, my suggestion is to turn up the radio. The squeal hurts nothing.

One of the other posters offered some good advice. The oil leak you suspect to be the main seal very well could be the oil filter housing, cooling lines or another source. Wash the engine thoroughly, then start looking over, under around dilligently until you find EXACTLY where the leak is. I went through a rear main seal wearing out, it was at 380,000 miles and it went from zero leak to GUSHING all of a sudden. I'm not saying they all would fail in that way, but that was my experience. As psfred said, I pulled the motor and did an overhaul at that point. It just didn't make sense to repair the seal and leave everything else alone. Check it all out before you condemn the rear main seal.

I expect it to take 6.5 quarts of oil when changing the filter. I would recommend a universal grade oil. These are specifically designed for diesel engines, and what the truckers use. Examples are Chevron Delo(that's what took my original 240D engine to 380,000 miles), Mobil Delvac, Shell Rotella T. In our area they have the Shell and Chevron at WalMart. You can always get it at the truck stops or truck service shops.

psfred said 90W in the transmission, and maybe that's what yours calls for. My manual showed motor oil. I put in 10W30 Mobil One several hundred thousand miles ago and my transmission has still never been apart.

I have used power steering in quart containers from Auto Zone for years with great results. Don't use ATF even if the manual says so. It has changed drastically since that car was built and is not good for the seals. Power steering fluid is more expensive than ATF, but these power steering components are EXPENSIVE, don't take any chances.

You certainly will want to adjust the valves because you don't know when it was done last. I personally have found 15k mile intervalse to be excessive, but I will never argue with too much maintenance. psfred already gave you the story on the valve cover gaskets, they basically last virtually forever as long as they don't harden.

Everything else has been answered quite well. As far as I'm concerned the manual transmissioned, 123 series 240D is an absolute masterpiece of engineering for it's time. Not fast, not great handling, but solid and longlived.

Enjoy,

Thanks so much Larry for the advice. A couple of questions though:

You don't think that the syn oil used in the manual tran. would cause some leaks? I know you shouldn't use it in the engine...but is it ok for the tran. as you suggest?

You suggest replacing the plug on the back of the injector. Is this just some kind of washer? Any special tools or instructions to remove an injector?

I will look long and hard to see if the leak is actually the rear main seal. It might just be the upper pan or something like that. I will have to clean that area of the engine well to get a better look.

Anyone else use anything different besides what was mentioned for their manual trans fluid?

This is a great forum. I really enjoy reading and learning from others who truly enjoy their cars.

thanks,
mike

[ricali]

Just like to add my .02.
I had a similar problem at the base of the injectors. The problem turn out to be the sealing washer under the pre chamber I agree with washing everything down and try to pin point the leaks.
A lot of cleaning and wiping sometimes saves a lot of quessing.

How else would you know where a diesel had been parked if you didn't see little oil drops on your nice driveway.

[michael rybikowsky]

After reading your questions and replys I think you have bought in over your head.What did you pay for the car.I bet it was a steal Sell it and buy a ford.

[skalie]

Originally posted by michael rybikowsky
After reading your questions and replys I think you have bought in over your head.What did you pay for the car.I bet it was a steal Sell it and buy a ford.

May I be the first to disagree with that codswaddle.

Mike,

When I changed to synthetic in my transmission it had quite a few miles and there was no leaking problem. I believe this to be because there is no combustion in the transmission causing the nasty contaminants like you have in engine oil. My transmission has never leaked with Mobil One. I indeed would not change my older engines to Mobil One for that reason.

The plug in the rear injector is merely a short piece of that cloth colored hose with a plastic plug inserted in it. ricali brings up a good point about the seals under the injectors, but I suggest that you replace all the cloth covered bypass hose first, then if there are still leaks, replace the injector seals as ricali suggests.

As far as trading it for a Ford goes, that's your personal decision. I get the impression that you are familiar with working on cars, your just new to the breed. I was completely lost when I started working on my Benz diesels, but like anything else you learn as you go. Unfortunately I went about 12 years driving and maintaining them without mercedesshop. I would have ramped up much quicker if there was such a source of information for me early on.

Enjoy,

[michael rybikowsky]

bible I may be wrong I often am.I get the impression that he dosn.t have a clue about working on cars.

[MarkM]

sounds to me like Mike was asking all the right questions.....sell it and by a Ford?!?!?! C'mon! I mean really!

Regarding the AC, I converted my 300D to R-134 by replacing everything except the evaporator. I would follow what Larry said, however I might differ regarding putting old hoses back in....after going to the trouble of taking it all apart, when I did my car it was tough for me to put back original parts knowing that anyone of them may fail soon. On the other hand I have heard of quick and easy conversions that worked.

On mine, I made a few modifications in an attemp to improve cooling....I replaced the original condenser with a universal parralel flow...i put in the biggest one that would fit, and had to have some custom hoses made to make connections. I also wired the aux fan with a relay to the compressor circuit so it would go on whenever the compressor went on (not necessary when tooling down the highway, but helpful during stop and go). The system works very well, even on humid days in the 90's...reasonably well for short hops. Central vent temps down to 41 deg F when fan on high and max cool. The real limiting factor is the size of the evaporator..even if you could maintain constant evap temperature of 33 deg F, you would have limited cooling capacity during very humid weather due to its size....nothing like the the big evaporators on R-12 systems in big older american cars that blew snow!!

good luck,

mark

My books all say ATF in the Manual Trans, I however don't personally believe it matters between a good grade of motor oil, or ATF. I do believe however that 90 weight gear oil is too heavy for the application. Clearances for this weight were not designed in by the manufacturer.

On the fuel leak, dollars to donuts you have a fuel return line, or the plug on the last injector leaking. Do yourself a favor and replace all these little devils, including the one piece to the filter. Also a good autoparts store will carry replacement line that is far superior to the original woven outer layer line. And carry a spare plug for that last injector to avoid unexpected diesel fuel smell, unless you really enjoy it.

Check after cleaning, the oil filter adapter to block junction for your leak, I also have seen a couple of oil filter housings with leaks at the inner stud that holds on the top cover. Check oil pressure guage line connection at filter also.

I agree, 123 manual trans Mercedes is a Masterpiece of Engineering. I worked on them from the time they came out in 1977 until I retired in 1993. I was a registered technician with Mercedes Benz of North America, as well as owner of my own shop for several years.

I have had my 115 1976 240D since new, it also is a manual shift. I have ran it Turbocharged (my own installation) for the past 15 years or so, with no ill effects.

Rob