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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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Discussion Starter · #1 ·
Hi All,

I am looking to buy a 240D, and came across a local car with a problem. The owner claims that he went through several vacuum pumps in very short order -- each within days of eachother. At first he just rebuilt the pump. But after the 3rd failure, he bought a new one and the new unit failed as well.

He did some digging, and claims that there it too much play in the pulley being driven by the crankshaft. I have not seen an exploded view of these engines, so I cannot verify that this could happen. The current owner says that the motor needs a new crankshaft.

Has anyone seen this happen? Could this be something other than the crank? Is there a source online for an engine diagram? Should I bother looking at this car any further?

Any comments or suggestions are appeciated!

Thanks!

Bill
 

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The vacuum pump is driven off a cam mechanism on the front of the injection pump. If the crankshaft had too much play, there would be serious issues that would be very noticable, i.e. knocking, broke timing chain. Never heard of a bent crank.
What is going bad about the vacuum pumps. Not sucking, bearing coming apart, ?? This will tell alot.

For diagrams, see...

http://www.detali.ru/cat/oem_mb2.as...+++717.400&CT=M&cat=004&SID=03&SGR=015&SGN=01

http://www.detali.ru/cat/oem_mb2.as...+++717.400&CT=M&cat=004&SID=07&SGR=060&SGN=02

http://www.detali.ru/cat/oem_mb2.as...+++717.400&CT=M&cat=004&SID=13&SGR=090&SGN=03

Give us some more info on the car , the condition and the price. We'll tell you if it seems like a fair deal.


Jamie
 

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1985 300TD Wagon
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408 Posts
If the flange of the injection timer is damaged it'll eaten any vacuum pump in a short period of time. Make sure you renew the bronze bushing as well.
And you need a new thrust piece for the oil pump axle as well.
Since the injection pump has to be removed to make this all happen it's not really a regular do it yourself job! Find someone who's been there before! It shouldn't be too costy; although the timers aren't cheap (a good secondhand one would do).
 

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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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36 Posts
Discussion Starter · #4 ·
Okay,

I waent to look at the car today. Short of the partially disassembled motor, it is in great shape. The interior is great - minus the driver seat springs. The body and paint are really nice. It has 175K miles on it.

I am very confident that the issue is a sheared off harmonic balancer pin - the HB is just free spinning. The crank bolt is stationary when I spin the HB. The timing chain is intact, and everything else looks pretty good engine wise. The owner has had this vehicle maintained well - it shows.

How do the HB pins shear, is it purely an issue of inadequate torque?

What are the chances that the the crank has been damaged? Would I need to order a new HB as part of the repair? What is a good source for parts?

Now onto the problem that started this for the owner. He swears that the problem is the vacuum pump. He says that the cam is extending too far, and this is why the diaphram in the pump keeps breaking. The cam feels very solid to me. There is a spot on the cam face that has been damaged, indicating posible mechanical bearing failure. Any thoughts on this?

Should I pursue this vehicle? I am a good mechanic, and am not too conserned about the HB. THe vacuum pump is new to me, but pretty clear. The reassembly might me tricky, but I am hoping many of you have the ability to post pictures that provide a good illustration of how it should look.

THe car comes with a whole bunch of spares as well.

Any additional insights would be great.

Thanks for your help!

Bill
 

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1985 300TD Wagon
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408 Posts
No!!!!
Leave this vehicle where it's at!!!
It's a bummer but the crank is definitly damaged beyond repair (expensive item and repair)! If the injection timer is protruding the guy isn't telling everything correctly. This can only happen if the bushing is wrong or the spacer or things like that, this resulting in the chain tto be out of line causing the rails to wear more sideways.
So with other words get the hell out of there, someone is trying to sell the hopeless mess he made. Intentionally or unaware, it will cost more to repair then a complete and even better car!
 

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Where are you located? If the car is cheap enough, you may do good to buy it and a good motor from a Pick n Pull and swap out. Not too hard to do.

Maybe the injection pump timer/vacuum pump cam assembly went bad? Anyway, sounds like someone with experience in this engines needs to take a look at it.

Jamie
 

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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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Discussion Starter · #7 ·
I am in the San Francisco area.

The owner has freely stated that the car needs a new motor. He is not hiding this fact. The thing that is funny is he is saying this because he thinks the crank is broken - the HB flopping around.

I am open to an engine swap, but would like to know of a good source in the SF area. I have seen some beaters on Ebay, but do not want to deal with it. What would I expect to pay for a motor?

Before doing this, I would like to fix the HB and see if I could find out more about the Vacuum pump. Is there a way to measure the proper position of the cam face to verify the unit is running out of spec. The condition of the car, and milage do not suggest that any of this have been worked on.

It is a gamble, the question is, is it worth it if I have the ability to manage all of the mechanical stuff -- with assistance of course by the folks in this forum.

Thanks,

Bill
 

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Concerning the harmonic balancer, is just the outer ring spinning or is the inner hub that bolts onto the crankshaft with the large center bolt spinning too? The outer ring is mounted in rubber, so if just the outer part is spinning, the rubber simply rotted away and a new balancer will fix the problem. If it is spinning on the crankshaft, the shaft may be damaged beyond repair.

As for the pump, it sounds as if the owner thinks the roller assembly is pressing the diaphragm too far, and apparently breaking the lid. Correct? If so, the problem may not be that the diaphragm is being moved too far, it may be that it is not moving enough. There is a thrust washer, or at least a bearing with a thrust washer attached, behind the injection timer (the part the cam attaches to). If the washer is missing, the cam track actually goes back too far and the bearing on the pump looses contact with the track. This causes a jackhammer effect and can destroy the pump. You may question him as to whether the injection timer has been removed at some time, and if so, might have been assembled wrong. Also, there should be little to no moviement in and out of the injection timer. If there is, that is your problem. If there has been breakage of the pump, I would seriously consider replacement of the timing chain and camshaft supports (if cracked), as the metal may have gotten between the sprockets and chain.

I don't know where the guy got the information that the crankshaft is related to the pump breakage. If it is a manual transmissioned car, I have seen engines run with thrust play in the crank with no problem (have heard manuals have this problem more than automatics).
 

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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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Discussion Starter · #10 ·
Here is the update.

I bought the car. It was delivered on Friday. The motor is in a state of partial disassembly, so the puzzle to put it back together has started.

What I am planning on doing initially is getting the motor back together for the least money possible to get it to run. I am hoping that this will allow me to do my own diagnosis - with the help from these pages. A lot of the stuff the PO has said, does not make complete sense. He was not a mechanic, he was technical, but definatly not a mechanic. If there are any tips on getting this running, I am all ears! And the journey begins!

I went right to work on the spun harmonic balancer. A PO had broken the bolt off deep inside the crank. I have succesfully removed the portion that was broken inside the crank -- those years as an apprentice machinist payed off! The hole is now clear and the threads have been chased with an 18x1.5 tap.

Now that this is done, what is the best source for a new HB, bolt, dowel pins, and 3 washers?

I put the questionable vacuum pump back on. I could rock it on the cam while it was still loose (only a coupl of bolts holding it on), and I could feel the pump still pulling a vacuum. I don't know if this is false hope, but an interesting observation. There was some damage on the cam face, thus, an old pump must have had a catastrophic failure. Is there anythng I should look at here. I did not that the cam bolts were loose. I tightened them up. I have seen that some drawings have skirted bolts (I am assuming shoulder bolts?) here, and others do not. Which is it? Does it matter?

I put the valve cover back on. The cam looks new - I am sure it is not, but interesting none the less. The timing chain looked fine, but I did not check for stretch yet. Can this be done without the HB in place?

Any other advise so far? I am really waiting on the HB now.

Can the motor be run monentarily without all of the accesories hooked up? How do I prevent a runaway? I will have the phone book handy.

Thanks for any comments!

Bill
 

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Go to a Pick & Pull and get the balancer, bolt, etc. While your there, take off the vacuum pump from the scrap engine so you can see how everything goes back together. The motor can be run for a few minutes without any belts on it. Just be careful not to let it overheat. You should be able to still use the STOP lever to kill the engine. In case this doesn't work, stuff a large towel into the air cleaner intake.

Jamie
 

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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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Discussion Starter · #12 ·
IT LIVES!

I pulled a HB from a junk yard. I put it all back together and it started right up!

There is a big oil leak out of the side of the block however. There is a hole in the block just aft of the vacuum pump. It is squirting oil. What goed in this hole? I do not see any hoses or brakets that attach. Seeing that the car was partially apart when I got it, there is a chance that the PO lost something.

Can anybody help? Any diagrams/pictures of this area that will assist me?

Thanks,

Bill
 

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I assume the hole is man-made. It may be for the oil pressure line that feeds the injection pump. You should have a plastic line the bolts with a banjo fitting into the side on the IP and runs to the block in front of the IP. If this is gone, you will have a oil leak in the area described.

Jamie
 

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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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Discussion Starter · #14 ·
Yes,

It is man made. It does look like something that a banjo fitting would connect to.

What is the purpose of this line? Is it just an oil supply for the IP?

Any pictures or diagrams out there?

Thanks,

Bill
 

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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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Discussion Starter · #15 ·
Any possible damage to the IP without this in place? The only oil leak I saw was from the hole in the head. I plugged it. I ran the motor for about 30 minutes to look for cooling and other leaks.
 

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1985 300TD Wagon
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The IP has 1/4 litre of oil in it if everything is allright, the oil does return via axle/timer. So it get's hotter and dirtier without refreshment.
Make sure when you order a new oil line and banjo bolts to include 4 copper o rings.
 

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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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Discussion Starter · #17 ·
Okay,

Just took a look. The IP oil line is in place. The hole in the head is about 1 inch below the connection for the IP pump. Any ideas? If it is supposed to be a plug, what size? There is a lot of old oil in this area and on the engine bay. Could it have been missing for some time? I do not see anything else in the area that could be a possible connection.

What a great car to work on! Everything is so visible!

Bill
 

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On my 300, everythings not so visible! The power steering pump and bracket are sitting directly over that area. But from what I can see, there is just a plug there. I can't readily find it in the fische, so I'm unsure of the size. Your best best would be to go back to where you got the balancer, and get it off that engine. Can you tell if there is actual oil pressure coming from that hole, or is the oil just slashing out? I'll try to snap a picture tonight.

Jamie
 

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1980 240D OD stoped at 175K, 1992 Volvo 740 Turbo 185K, 1992 Volvo 740 200K
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Discussion Starter · #19 ·
I went to the yard after work. The parts car I looked at had the same hole. I looked at a 5 cyl, and there is a bolt in the hole. Looking into the Vac pump hole, it looks like the end of the bolt rides on the timing chain at the quadrant of the timning chain sproket. Is this a tensioning device? Does anyone have the part number and name as found on the 240d? I will need to order one.

Thanks!

Bill
 

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I believe what you're looking at is the screw, number 615 052 01 71. It is simply a plug with a seal ring. I have read in manuals that Mercedes had a special tool that could be placed in the hole to lock the injection pump sprocket in place while working on the engine, I assume for work on the camshaft so the timing did not get thrown off. The screw does not normally contact the timing chain, it is just a plug. The old OM621 diesels had the same plug/hole.
 
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