Slow and Clean OM617 Turbo Complete Rebuild

[Mersadie]

Well, I can now say I understand why there are only a handful of people who dive deep down into the depths of these older Mercedes engines. I suppose its not worth spending thousands of dollars on a rebuild to most people when you can go buy a decent running engine for a couple hundred dollars. I suppose its most interesting to everyone to see the pictures and hear the struggles and successes of other peoples journeys. So here is a thread that is going to follow this build from the start to the beautiful moment where the key turns and the engine is running again. This is the exact opposite of a quick and dirty rebuild where it takes one weekend and $100 in used parts. Be warned, this will be EXTREMELY Picture heavy. but that is what everyone wants isn't it? Hopefully this can end up being a very helpful and informative thread to all the wrench-ers out there! I also hope that this isn't the last of my threads, and by the time im done with this car I will have yielded many helpful and informative threads on all the cars systems. So.... Here we go.

Obviously, the first step was to remove the engine. An engine puller is 100% absolutely necessary, with a leveler being extremely helpful to lean it back so you can get the tranny leaned back. This step is fairly simple and doesn't have too many tricks... The oil pressure gauge is always a tricky line to get off... and don't forget the ground cables. Other than that though, label everything and that's the easy part. I'm sure most people have the issue of their engines leaking EVERYWHERE, and honestly, that was one of the main reasons for starting this project.... So once the source of the leak was removed to be fixed, it was necessary to clean up all its mess... It took about 2 days, and the pictures don't really even do it justice, (see attachment. Sorry no before picture, switched cameras 3 times throughout this whole project) but after many bottles of different cleaners and rolls of paper towels the engine bay was a beauty. Simple Green seems to be a praised product by many of the people on this forum, but when it came down to it, it didn't really cut it. I made a secret potion that was a mixture of simple green, and like 3 different cleaners. It worked good for the light stuff, but anywhere that was flat there was a very thick layer of dirt oil mixture.. Oddly enough, foam oven cleaner did a great job. sprayed it on thick, let sit overnight, and it literally wiped off the next day.
Next was the disassembly of the grotesque engine... I will write that up soon. There isn't very many pictures from the beginning of the project, but gets heavier as time goes on. Please leave your comments and questions below!

[oldsinner111]

thats what i use oven cleaner to strip grease and paint so I just have to repaint

[mach4]

Looking forward to future episodes documenting the process.

[Colorado220]

Looking forward to the project!

[Mersadie]

Ok, so I uploaded to the Engine Bay picture on the last post. It didn't upload last time. Sorry there was no "before" pic.... but im sure everyone has seen a disgusting greasy and grimy engine bay. You should be able to get an idea of just how bad it was with this picture of the engine before cleaning... it was horrid. I've decided to not paint the engine bay because I don't want to do a crappy job with a color that doesn't even match.... I plan to get a paint job within the next year hopefully, so that can be done then.

So, there are no pictures of the engine fully assembled, but once again, if you're reading this thread you've probably seen an om617 with all the pumps on etc. The engine is overall extremely easy to disassemble. There are just a few quirks that you have to be aware about before you begin so that you don't end up breaking things.... And yes, I might be speaking from experience. It is 100% MANDATORY to label every part that you take off. have a big fat box of ziplocs and a sharpie and you will be so happy when it comes time to assemble. I suggest putting a piece of masking tape on the bag and writing on that because now that i am back to the assembly point i am seeing that some of the writing has rubbed off and that could become disastrous. After all the pumps and brackets are removed (see first photos) you hit your first difficult thing. All the timing chain rails, which are usually in major need to be replaced, are attached by pins that are threaded on the inside. They have to be removed via slide hammer. It can be tricky but if you get the right bolt/washer/socket(or tube) combo it should be fairly effortless. Make sure the bolt has plenty of threads in the pin so you don't just shear the first few threads off... A tap and die set is very helpful throughout this whole build but especially here if they are really caked. Next is the harmonic balancer. I pulled this with a generic pulley/ balancer puller which worked fine, except for the fact i used the balancer bolt and washer to rest the tip of the puller on so it didn't mess up the threads in the crank. Well, to my surprise, the balancer keys are round (see picture). so when i started cranking down and pulling with the puller and that bolt, it sheared the keys .... Don't make that mistake. watch what you use to protect the threads... make sure it doesn't cover the keys. When removing the head it is beyond necessary to make sure you get the proper triple square twelve point bit for the head bolts. You will strip them if you try to use anything else. I drew out the diagram of the head and head bolts (see pic) so I could place them in it. This is necessary if you plan to reuse head bolts, but nothing more than storage if you're buying new ones.

I'm sure that some veterans out there know all of this stuff, but i really hope my experiences can help some of you guys out there so you don't go through the same hassle as me WHEN you tackle your projects

As you can see this engine was horrific as far as dirtiness goes. I think that the majority of the leaks came from the turbo drain tube, the oil cooler lines, and many valve jobs without replacement of the valve cover gasket... I dread the day when she starts leaking oil again.....

[Junkman]

There was a post on "leak ferr engine" one of the regulars posted. Basically use good quality gaskets and JUDICIOUS amounts of black RTV or RightStuff. I had the passenger side parts off to the head. It's clean so far.

[sag]

any up dates?

[Mersadie]

Originally Posted by Momoclo

The ONLY place on the engine where RTV should be used is the upper oil pan surface (there is no gasket).

If you absolutely insist on using a sealant, use High Tack. No matter how little RTV you use, it will squish out and contaminate the engine internals. Using a "JUDICIOUS" quantity is guaranteed to cause internal problems/damage, primarily plugging the oil pickup screen. Bits that get past the screen can also wedge in the relief valve and cause low oil pressure issues.

I have to second this. We bought gasket kits for the whole engine and replaced every single gasket and used RTV on the upper oil pan.

I am sorry it has been so long since the last update. I had an accident about a month ago, involving this engine. We were attempting to crimp the new masterlink on the timing chain with a tool that we found at harbor freight that we thought might suffice. The tool was a harbor freight chain breaker. (see picture 3) It worked fantastic on the first one. I walked over to watch the second one and the rod on the end(very high carbon cheap steel) shattered. I had just come in the garage and didn't yet have my safety glasses on. So of course out of everywhere it could have gone a 4mm piece entered my left eye. We rushed to the emergency room and thought that the black spot in my iris (see picture 2) was the steel and they would be able to remove it. We later found out that the black spot was just a hole where the steel passed through my iris, shattered my lens, passed through all of the viscerous gell, and punctured my macula, which is the center of your retina, the part that you read with. So I was then rushed to Emory for intensive surgery. I no longer have a lens. Its been an intense recovery process and it has left me partially blind in my left eye(still healing, God is good).

ANYWAY! The moral of the story is wear saftey glasses always and dont buy harbor freight for anything important!!!!

There is one thing good to come out of this, and that is it made me so upset that I was so close to finishing that engine and it had defeated me so I got my dad and my grandfather and within 4 days from when I was actually able to go outside, we had the engine in the car running So that made me happy, and weve actually been driving it and working some kinks out!

Im sure you guys would love to just see the finished project, but I'll just pick up where I left off

I left off at Engine Dissasembly.... SO the next would be a stupid amount of cleaning. If you have a car that is so greasy you have to literally SCRUB every part down 20 times before its some what clean, it is just worth taking them to a machine shop and letting them jet wash it for you. Its such a time consuming, grueling task that its just worth spending a couple extra bucks to let them do it. Plus They are gonna get it cleaner than anyone ever could by hand. (Cant wait to show you the pistons )

After cleaning, I would say the next step is Ordering Parts and Machine Shop. LISTEN TO THIS NEXT STATEMENT. Find someone who knows what they're doing and is confident. The grey-er his hair the better. We took the head and the block to a guy that all he did was v8's. We decided to leave it there because it was close. Like 3 minutes close. He was the nicest guy in the world, but was scared of this engine. The head and engine sat there for 2 months (maybe 3 ) and all that happened was he honed the cylinders and rubbed down the head with high grit sandpaper. WASTE OF SO MUCH TIME. We finally broke down and drove an hour to this machine shop in acworth (Goza Machine for anyone in north GA area) and we knew he was good. He could hardly hear us, waddled around, and had all grey hair! He had a huge, organized shop, he had driven a diesel mercedes before, and worked on domestic and foreign. Now, you have to take your stuff to the machine shop before you order parts so they can measure everything out. So within a couple days we were ordering cylinder sleeves, all new exhaust valves, valve stem seals for him to replace. We also brought him all the pistons and he told us they were all worn equally. Very little though. which is incredible because they had 300,00 miles on them. and FYI you cant get a new set of pistons for under $1500 So he decked the block, the head, put the new sleeves in, bored them to the pistons, pressure tested head and replaced exhaust valves, and replaced all stem seals. He also washed everything, including pistons. It all looked brand new.... I think that that set us back $1800....?
After that the rest of the parts were ordered. We love pelican parts. Probably spent $2500- $3k there now. Just on the engine. I dont even feel like listing out everything weve bought, would take days. Lets just say everything that could possibly wear and more... besides pistons.

When it comes to assembling the engine, its pretty easy... Its amazing how everything just wants to go back together. Just make sure you have a nice torque wrench! Im also not gonna repeat myself and say stuff that is easily found on these forums or in the haynes manual. (get one).

I will say, dont try to pull off the power steering pulley unless you have the mercedes puller. bad idea. Also, unlike gasket sealerm you can never go wrong with judicous amounts of assembly lube. everywhere. bearings, cylinders, everything.
When painting the block and head, and everything else for that matter, spend your time in masking and prep and use high heat engine paint. its worth it. Use naptha to remove all traces of grease or oil, and spray. I did 3 coats and its beautiful.

MORE TO COME.

[mach4]

Originally Posted by Mersadie

We were attempting to crimp the new masterlink on the timing chain with a tool that we found at harbor freight that we thought might suffice. The tool was a harbor freight chain breaker. (see picture 3) It worked fantastic...

Can you describe how you used a breaker tool to crimp? I've looked at the tool and thought that it would be possible to modify it by making a "v" shaped insert that would make the crimp like the real tool, but I can't conceive how you did it. Of course given your life shattering experience with the attempt I'd not try it myself and hopefully others will be dissuaded as well.

[JustSomeOlddude]

Hi Mersadie Hope that you are recovering.
I just created an account here because i stumbled across your experience with Harbor Freight.
So very sorry that happened to you and i feel motivated to share your warning.
I too have had very bad experiences with HF tools, either the metal was too soft or it was too brittle. I bought a hand held grinder and it melted and seized up. Apparently, instead of of bearings, that grinder was built with bushings. The dust from the tile i was cutting clogged the bushing. On another experience within 5 minutes Pneumatic Cut-off Tool just died. After exchanging it the same day, the new one died again within 5 minutes on the same job. And yet in another experience a socket breaker bar bent in half.
If your'e working on engines , it's worth it to pay extra for quality tools.

[Diesel911]

Originally Posted by JustSomeOlddude

Hi Mersadie Hope that you are recovering.
I just created an account here because i stumbled across your experience with Harbor Freight.
So very sorry that happened to you and i feel motivated to share your warning.
I too have had very bad experiences with HF tools, either the metal was too soft or it was too brittle. I bought a hand held grinder and it melted and seized up. Apparently, instead of of bearings, that grinder was built with bushings. The dust from the tile i was cutting clogged the bushing. On another experience within 5 minutes Pneumatic Cut-off Tool just died. After exchanging it the same day, the new one died again within 5 minutes on the same job. And yet in another experience a socket breaker bar bent in half.
If your'e working on engines , it's worth it to pay extra for quality tools.

I have had decent luck with Harbor Freight stuff. When you buy cheap you take a chance.

I have a few of their Angle Grinders the hand held tool that welders use to grid welds or bevel metal. The cheapest ones quickly developed bearing noise. Cheap and not hard to replace a better quality bearing.

Concerning eye protection. Most powered stuff comes with warnings on what protection to use although even that does not guarantee protection. I have been wearing corrective lenses/glasses since I was n the 2nd grade and was always pissed that was so.

However, my eyes have been saved discomfort or injury innumerable times where my Glasses protected my eyes. Especially after I started working as a Mechanic.

The most memorable one is I was about 11 years old and frying some Bacon which popped and spewed about 1/4 teaspoon of scalding grease directly onto the glasses lenses of my right eye. It was bad enough that it ran off the lens onto my cheek bone and burned the skin there but it would have been much worse if the hot grease had hit my eye.

[Mersadie]

These wouldnt go on the last one...
#4 - new sleeves
#5 - new valves

[Mersadie]

Crap. I just spent like an hour typing a post and it didnt post and got deleted. Ill have to wait till tonight to type it up again... sorry

[Simpler=Better]

Ouch! Sorry to hear about the eye, but I'm glad you didn't lose it completely.

Those pistons are gorgeous!

If you're paranoid about timeouts on the server, typing it up in notepad & pasting over is sometimes worth the work...but you already found that out

Make sure your insurance company sees those receipts and marks down the full value. If you get hit you don't want to lose the $$ you've poured into her.

[Mersadie]

Like I said, dont try to pull off the Power Steering Pulley without the special puller.....
https://www.flickr.com/photos/113280060@N03/13308885764/lightbox/