OM 617.952 engine people I need your help
 

Ok this is the third used engine I have obtained. This one from a friend. He gave me his word on how well it ran. I trust him on that completely.
It had an oil leak from the head gasket I noticed after I got it to my shop. I took off the head and brought it in for checking at a machine shop recommended by a trusted Indy. Its cracked RRRRG.S***,F***,D***.
The cracks are around the pre-chambers on two cylinders. Maybe it was overheated I don't know. Now I'm looking over the block and I see the cylinder liner and block have a tiny gap. I cant tell if it is corrosion or what. It looks to be on a couple of cylinders.
Is this acceptable. Should I go get my money back. I have another head but it needs a valve job. I would get that done, but there is this question over the block now. I'll take more pics later. the battery ran out on the camera so only one for now.

Yes


..

more pics
 

It has decent cross hatches. Is it worth a deck surfacing? It probably has to be disassembled for that right?

and more
 

This one is from the other side of the same cylinder.

I'll get the head tomorrow for pics
 

Its a bummer since my friend was actually reluctant to sell it to me. He wanted it because it ran so well. Now I have to bring it back in pieces. Not easy but I think he should understand. Not exactly what I had in mind. Very frusterating.

What's the stuff on the top of the piston crown?

http://www.peachparts.com/shopforum/...13057_3009.jpg

Is it just muck and gunk?

As for should you get your money back; how do you think your friend will react to the evidence?

I'm like 95% sure that there's no trouble with the corrosion between the liner and the block shown in this picture

http://www.peachparts.com/shopforum/...13042_3000.jpg

It doesn't look like there's evidence of any slippage to me. If the liner had dropped then it wouldn't be ideal...

...however it could be a good idea to get a "real life" second opinion from a decent machine shop.

Question =>

How are the sides of the cylinders? Can you see any evidence of uneven wear?

Do you have a bore micrometer?

the sides looked pretty good
 

I can see most of the crosshatch marks. towards the top of the cylinders it seems to be a little more worn. I do not have a bore gauge. I may get a cheap one today from Harbor-freight.
There is no way to rotate the engine with cylinder head removed, correct?

The stuff on the piston crown is like a carbon crud. Its slightly gooey and doesn't want to come off easily. I even put ATF on it for a couple of days.
Maybe I'll bring the block down to the machine shop for them to inspect.
Can it be decked while assembled. I see a possibility for that if the timing chain was to be taken out. That would be a bunch of work.

So long as you don't mind "loosing your place" turning the crank is perfectly safe - just make sure that the timing chain doesn't get tangled in the guides; if the chain kind of doubles up and jams in the guides then you could damage them.

Strange - can you provide a zoomed in picture? Was this engine run on non diesel "products"?

I think that that is a good idea - pictures on a forum isn't the ideal way to form a diagnosis / plan

I don't know for sure - I've heard of companies that do re-bores with the engine still in the vehicle (they don't tend to have the best reputation!)

number one cylinder is not looking so hot. Unfortunate
 

some light scoring . It must be from coking. That black stuff is more like glue or something hard. It is not east to remove, especially without scratching.
Well this one looks to be not so hot of a choice after all. I'm not having luck with used engines as of late. Three engines from wrecked cars, 2 that ran decently, all of them have major issues.
Vegi oil is the suspected in contributing to the demise in two of them. I think I may be through with used engines.
Here is a photo of the scoring. You can just barely see cross hatches through the score. I ran my fingernail over it and could not feel anything. It must have coked rings or something.

That doesn't look too good =>

http://www.peachparts.com/shopforum/...4-18.43.26.jpg

But I think it is very difficult to judge this with photos. The sides of the cylinder walls look shadowy which "in real life" (as in if I was seeing it for real and not in a picture) would probably indicate uneven wear. When I took my block along to an engine builder he pointed out the shadows to me and said that there wasn't any point in measuring it; he could see that it was worn.

How many broken engines have you got now? Have you reached the point where you can start making a new one?

You only need five good pistons and five new liners (bored to size) a good crankshaft and a refurbished head etc etc...

Ive got three engines at this point. An 81 TD engine from a rolled car. an 83 300DT engine from a wrecked car, and this 85 300DT engine from a rear ended car
The 81 TD engine is in the car now and has a low #5 cylinder. If possible it will stay there until another is ready to replace it. It drives ok actually. Smokes a bit but starts easily as long as it is not too cold. Water injection may help this one, but I dont want to use funding for that. I may need it for other parts. but that is tempting. Compression Psi on #5 is 225
the 83 engine is already taken apart and sits in pieces a my shop. This motor must have been run out of oil or something then repaired. the crankshaft is not original. I can tell because it had mercedes written in paint on one of the journals. Only it was spelled something like "mersedez". After I saw that i gave up on trying to fix that motor. It is sort of my practice piece at this point.

OK so if you include this engine you've got two - is making one from two an option you're willing to consider? This way you keep the friendship rolling along...

FYI-You can make up a WI system for around $150, buying new parts. If you scrounge you can do it for less. A Devil's own pump is $100 new, a big nozzle from McMaster-Carr is $15, tubing and wires you can get at your local hardware store.

Need more info on the 85 300DT

Miles ?

Did you have the engine running at any point?



Pending that info, you need to realize that the motor is used and nearly 30 years old so it will show wear. From the pictures, none of the "flaws" look fatal. Find any used good running older car then take it apart, you will see wear on that one too. Also, if you took apart a salvage yard engine any warranty would be void so don't expect a refund from your likely to be exfriend.

Some head cracks are acceptable no matter the brand. There are standards to judge reuse so check an actual MB manual.

There is going to be some visible line between the block and liner no matter the brand as you are dealing with two distinct pieces of steel.

The scratched / dark wall is a toss up, it may just be colored. Higher mile motors will have scratches / coloration and still run just fine.

What worries me the most about this project is that you rejected the other 83 300DT motor solely because the crank was marked with a paint pen rather than rejecting it because there was actually something wrong with it.

First of all I'm not loosing any friends over it. A salvage yard would take an engine back no questions asked as long as it is assembled and complete . All I have to say is it was not a good engine. I would get a trade in for credit not cash back.
I did not reject the 83 engine only because of the misspelling of Mercedes. The fact that it was writen on the crank as "Mersedez" did not give confidence though.
I removed one piston and saw it to be highly scored along with the cylinder wall. A leaking exhaust valve as well. After that I gave up on it because I didn't wish to rebuild the engine that needed new pistons. I would rather not install an engine that only gets me 50k miles before it craps out or starts running poorly either. It seemed to me to be a rudimentary rebuild or crank replacement. I'm not really interested in that.
Ill gamble with the 85 engine and put it together and do a compression and or leakdown test. I'll see where I'm at then.
I've got a good feeling about the whole project. I think that is what matters.

Just so you know the background I'm coming from, I've built many motors on a professional basis before, during and after owning / operating an auto repair shop for 10 years. Not as many as a production line rebuilder but way more than the typical repair shop.

Unless you have an established professional relationship with a specific yard, no questions returns are not typical policy. Call random yards , tell them you are going to buy an engine, take it apart ( head off at minimum ) and if it does not meet your standards you want to return it no questions asked. Please post the results.

At the end of this post there are polices from two random salvage yards.


The scored cyl and leaking exhaust valve were not in your original post only the crank marking. That new information changes motor status entirely. The miss spelling does not mean much, quick, without use of the internets give the proper spelling P-got ( Pu jo ) , Ren-alt , Mitsu , ( my luck you will be an English teacher or author. . )

That is reasonable and again, was not in your original post.


Two random salvage yard policies ( words in ### are my highlights )


Untitled 1
* ENGINES AND TRANSMISSIONS Absolute German warrants all engines for 90 days from sale against knocks and cracks in heads and blocks. Any motor cylinder head with a melted heat tab is sold “as is, with all faults”. Except as otherwise provided below, Absolute German warrants all transmissions, transaxles, and differentials for 30 days from sale to work properly without excessive noise. Absolute German recommends new oil seals and gaskets before installation of engines, transmissions, transaxles, and differentials. Absolute German does not warrant against oil consumption, oil leaks, other normal wear and tear, emission levels, seals, gas leaks, oil pumps, water pumps, belts, hoses, bolts, tightness of bolts, and accessories if sold with engine and warranty.

SoCal Mercedes Parts | Policies

Terms of Sale and Warranty Information:
All sales final.
6 month warranty on in stock used parts unless otherwise stated on the receipt.
If a part proves defective, So Cal Mercedes Parts, at its discretion, will either provide a replacement or a refund.
#####
No returns without Return Merchandise Authorization Number.
#####
######
Warranty will be void if parts are not returned in the same condition they are sold. So Cal Mercedes Parts is not responsible for any parts that have been altered, modified, ##__disassembled__,## or damaged by misuse or accident subsequent to purchase.
#####

Engine Warranty:
Used engines are guaranteed not to have a cracked block, head, or bad crankshaft.

All parts external to the block and cylinder head (i.e. distributor, injection pump, manifold) are not warranted. These are left on for the installerÕs convenience.

Used engines are guaranteed against rod knock, excessive smoking, and excessive oil consumption.

Return Procedure:
If you have a return, defective part, or core please fill out a Return Merchandise

Request Form. If you do not have your invoice number, please indicate when your parts were purchased and your full name. You will then be emailed a Return Merchandise Authorization Number (RMA#) in 3-4 business days.

###
When you receive your RMA#, package the part securely and write your RMA# clearly on the outside of the box. ### Parts without a RMA# will not be accepted! ###
###

Once we have received your return, conducted an inspection of the part, and #### verified that the return meets the above guidelines, a full refund will be issued. ###

Yeah, yards are a bit of a gamble. But you now have a few parts motors to scavenge from in the future.

Update waiting for a refurbished head.
 

I'm having a decent non cracked head refurbished. It should be done soon.
I installed the original cracked head on the engine to see if i could get any pressure to hold in the cylinders. I checked number 1 and leaked heavily out of the exhaust valve. So no determination there as how good the rings are holding. Rockers were off for the test, so valve lash should be not an issue.
I figured it was worth it to waste a head gasket for the test. It was inconclusive unfortunately. So I am now waiting for the refurbished head and we will know when it is on weather this bottom end is decent. I am pretty sure things will go well. This motor was strong and did not smoke before so I'm crossing my fingers.
I have got a lot of other things on my agenda at this point that take precedence right now. Gotta Pay the bills. The cars are down on the priority list at the moment. Summertime is very busy. I have got to keep my art business as a priority. That is what pays. Mechanic work is just a hobby. Sometimes I get my priorities switched when I get sucked into a car project.
I want to work on the car until its done, but that is not reality.

Getting the head today.
 

I will install it asap. A new head gasket is on the way. I have new bolts and everything else I need. I'll do a list of items later.

If you take the block in for machine work, I would change the cylinder liners and have new ones honed to your pistons. Check your piston ring grooves for missing chips, since several of mine were bad. There has been much talk about how to change cylinder liners. Search for my post for how I did mine.

Removal is simple, you just drive a screwdriver down the gap and split the thin cast iron. I got new liners for ~$11 ea on ebay, but seems I have seen higher prices since. I heated my block over a camp stove and chilled the liners in my freezer. However, they didn't just drop in. If I did it again, I would get the block much hotter, maybe running a torch down the bores just before installing the liners. I would also sand the bores more. I used a sledge hammer w/ a thick steel block atop the liner. You don't want to hit the liner directly or it will crack. I have a shop press, but it seemed too hard to rig the block in it. You must deck the block after liners since they stick up a bit. I haven't done the machine work, since I don't need that engine yet.

I think it wont come to that. I hope.
 

I measured the cylinders and they are well within specifications. I will double check to be sure.
The rebuilt head came in 2 weeks ago. I just installed the pre-chambers and measured their depth. All is well there. the prechambers were reused but look like new.
I am now waiting on the Head bolt socket to come in the mail. I purchased the Hazet 990SLG-12. the 140 mm 12 point 12mm head socket. I was tempted at the local T55 socket, but i will wait. I dont want to strip any bolts.
the other parts I plan to install are as follows
turbo drain seal
chain Rail and tensioner with spring.
oil filter housing gasket.
new head bolts.
valve cover gasket
head gasket (of course)
manifold gaskets (of course)
Thats all I can think of right now. If anyone has more input it is surely welcome. I must have missed something. Is there a oil pressure relief valve or something in the filter housing to be replaced while its apart.

Seeing you've done all that--Might as well replace the Chain and the Vac Pump....

I too would consider the chain replacement but you need to have the crimping tool so that makes it a bit more complicated (if you had your crank out you could batt your eyes at the dealer and ask them to join the ends of the chain together for you and then loop it over the crank and up... but it isn't worth taking out the crank for this!)

The only other thing I think you might have missed is the gasket for the vacuum pump to block. I wouldn't be replacing the vacuum pump though (I'd be rebuilding it). You have to bear in mind though that I put way more effort into cars than most - so you have to take my additional recommendations with a pinch of salt. I aim for perfection and then get disappointed... rather than saying oh bugger it it will be OK...

I had those on my mind.
 

I will be covering those as well now that you guys affirm my feeling. The chain looks close to being only a degree or so off. rough method. The cam gear has some wear. I shined a flashlight to look at the crank gear and it looks ok from what I can see. I will likely switch the cam gear for another. Ill post a pic.
I hopefully will be able to find the crimper here on the rental program. I have done this before on my previous 240d.
BTW it says in the FSM a closed chain is to be used when rebuilding. I wonder if that is available from MB/IWIS. There is a cheap Beck-Arnely closed chain. I don't plan to go that route, but just curious.

Hazet
 

I just received the head bolt driver. I am hoping to have time to install the head on Sunday.
I have one question. Does anyone use the angle of rotation gauge, or is just eyeing the 90 degrees acceptable. Where is this tool available. I don't believe I have seen one available anywhere.
Have a great weekend.

You need to have a fair amount of leverage to do those 90 degree turns (in between counting one mississippi, two mississippi...) it is relatively easy to see 90 degrees on a long long grolly bar - the longer the bar the easier it is to see.

the head is on
 

It is on. The cylinders seem to hold pressure according to the leakdown tester. My tensioner rail pin bolt stripped but it came out still. Another is in town already for me to pick up. Somehow a local indy found me one in Oakland. The dealer hooked me up with the indy.Have you ever heard of that. They like me over at the dealer I'm often. My parts guy at the dealer actually called the indy to see if he could help since the only one from MB is in Germany.
So Im looking at vacuum pump related stuff and the rebuild kit is $220 for the Pierburg pump. A whole new pump costs $320. I'm deciding if its worth it for the new pump as my time is limited. I wonder how long it would take to rebuild. It looks rather easy.

The vacuum pump rebuild is an easy job if the screws on the cover aren't corroded in place. You'll loose time drilling out snapped off stubs but even then it isn't too too difficult. Before installing a rebuilt or new vacuum pump make sure that the bushing on the intermediate bearing isn't shot - check for end float on the intermediate shaft as per FSM.

By the way I've seen the whole pump for cheaper than the price you name - it was closer to the costs of the parts you quote => I think it was on ebay...

getting it buttoned up
 

I got it mostly together. I am still pondering the timing chain. It doesn't have any stretch when I line up the timing marks.

If this is an old timing chain and there is not an offset key fitted to the camshaft cog then you're probably not reading it right or you've got it wrong.

Take a look at chapter 05-215. It is expected that you'll see about 2 degrees of elongation after about 20,000 km

timing chain master link
 

So I decided to go ahead with the new chain. I have it here with the master link
It has been seven or so years since my first timing chain job on the old 240d.
My manuals are at the shop. Please forgive if this is covered in the book. I am looking at the master link. I have one question that i could use help with just in case I have to order a new link.
Should the center link should just slide onto the pins easily? The links are both pretty much identical and neither slides over the pin. Pressing it in seems like it wont work. Whats the issue. Do I use the one from the old chain. That seems odd. One link does seem to have a slightly lighter blue color. I can order a new link now and I'll have it tomorrow for assembly.
Appreciated
Chris

This is the way the master links are delivered today.
Before they had 2 different plates, one would slide on and the other one had to be pressed on.
There must be a tool available now,to press the center plate on.
I always ream one of the plates out, until I can push it on by hand.
Be care full if you do this, it has to fit really tight on the pins.

I have 2 master links now.
 

Ill be installing the chain this weekend as long as time permits. I'll go read the FSM and figure it out.

I may try
 

That sounds like it may have to do. I wonder why they changed. I would rather press it on if I can figure it out. I just can't picture it

timing done
 

The new chain has been installed. Thanks for the tips Mog and Stretch and thanks for Brian for the rental tool. I ended up just rolling the chain through, like Mog had suggested in a another thread, by leaving the outer link off and never letting slack on the chain while rollling it in. I had no issues. A helper was thankfully available to turn the engine.
I think Ill get a new vac. pump. I don't have any extra time to search for the correct bearing. If you add up the rebuild kit with the vacuum pump bearing kit it runs the same as the pump new.
Now I have a little list of things to do on this motor still before it gets hooked up to the transmission and moved out for installation.

For the vacuum pump I show what I chose (and why) here =>

http://www.peachparts.com/shopforum/diesel-discussion/339870-more-than-you-likely-ever-want-know-about-om61x-piston-vacuum-pumps.html

In either case - rebuilding the pump or replacing the pump (with new used or what ever) you need to check out that end play on the intermediate shaft before fitting it (also discussed in thread linked above as well as the monster one started by Beagle - link for that thread is in that thread...) because if the intermediate shaft is rattling back and forth you'll kill a healthy pump just like that.

timing device?
 

Can I check the endplay without removing the timing device? I would rather take off the IP if it can be measured that way. I read the article but I was not sure still. Ill have to look over the procedure for its proper removal.

See post #35 in the thread I linked

Intermediate shaft bushing replacement
 

Well I just measured the end play and it is 0.33 mm with .02 mm margin. It looks like I'll be getting even more of a challenge now. I've got the FSM and have read over the process.
I am eager to get this project working, but i have got a lot to do. Time is limited. It will get done one bit at a time. At least I have another ride, but I want to be in the Benz not the Ford f150. The ford is no pleasure to drive. It gets the work completed though.
Any ideas out there on a device to raise the chain out of the way to remove the timing device. I am calling my guy at the dealer to see if the special tool for that is available and affordable. I kind of doubt it.
the tool seems to be a bent pice of sheet metal to slide in there and keep the chain out of the way. its tool # 616589024000.
Wish me a steady hand.
thanks

Do you remember this thread "9 degrees of chain stretch"? Cell did a great job of documenting the chain replacement.

This post shows the tin plate he made for the Timer.

http://www.peachparts.com/shopforum/2801399-post32.html


Charlie

For the functionality of that special tool I just used several screw drivers to hold up the chain away from the timing device (one the tensioner has been removed).

Bearing bushing
 

So Ill be replacing both front and rear bearing bushings to clear up the play.
That means the IP has to come off as well.

Yep the IP needs to come off if you want to sort out this intermediate shaft bearing. It is a bit of a shame that you have to go through the drip test fiasco but it is better than a deed engine...

RIV
 

If I can get the tool. This IP has the port. I dont like doing the drip test either. I can do it with the engine out of the car though. That will be easier.
I rented it from MBDoc years ago I wonder if its available still.

Head decking
 

It says in the FSM, if you have the head shaved ,you must adjust start of delivery. I planned on doing it anyway.

I am waiting for the tool
 

I went ahead and got the chain lifter tool off the web. It was 60$ after shipping. I hope it helps. Maybe I'll put it on the tool list for rent. It likely wont get used much after this, but I can see it helping me along.

Timer front bearing bushing
 

I was looking on the other 617 engine I have apart and I cant see how the bushing comes out. I took the screw out that looks to retain it but it does not seem to have an easy way out. I measured that one and it is at the limit. 0.12mm play. It is supposed to be .05 to .12mm. I wont be using that one. I will give the dealer a call in the morning to see how long it is to get one here.
Thanks again

lock washer
 

I am looking at the FSM. It looks like i may need to get the lock washer off still. I am just practicing on this other motor.