[deanrantala]

Changing/replacing these o-rings requires removal of the timing cover.

The timing cover is sandwiched between the upper oil pan and the cylinder head.

Either the heads need to be removed OR the upper oil pan needs to come off.

On the W163, the upper oil pan can not easily (or at all?) be removed while the engine is in the vehicle. And given how easy engine removal is on the W163.. I just cannot see why anyone would not just pull it and perform a re-seal.

I have heard of people actually removing the timing cover without removing the cylinder heads OR the oil pans. Not sure how, but...

Honestly.. these engines ARE pretty solid. This particular ML320 has been to central Mexico (Hidalgo) and back to Colorado a few times already - PULLING 3,000+ pounds of enclosed trailer through some of the worse mountains you can imagine. Engine still runs smooth-as-can-be. Actually... it runs smoother than my 2009 CLS550 ever has.

A basic re-seal of the entire engine is NOT that bad of a job. Entire engine can be removed in less than 4 hours.

Cylinder head gaskets, new head bolts, new timing chain guide rails, and a "timing cover re-seal kit" from FCP all total less than $400 in parts. And I will easily get another 100k-150k miles from this engine. Still less than the cost of a single car payment for a new vehicle. So the end-result is (IMO) well worth the effort.

Not trying to advertise for FCP here, but.. for $160-ish.. the "timing cover re-seal kit" comes with it all: breather hoses (all of them), front and rear main seals, all the o-rings, VC gaskets, ETC. For another $100.. the head gaskets and valve stem seals are easily sourced on fleabay. The same for the guide rails.

The timing chain itself is a double-row chain. Very robust and really no need to replace it. I seriously doubt it will give you any issues before at least 800k. The guide rails are all usually starting to crack and fracture by now.

I have pushed the M112 well into 400K miles on another ML. Original transmission, too. My last ML500 that was left w/ the ex-wife was about to hit 400k before she got it. Still ran great last I saw it. That one also had original transmission.

Recently did this on an SLK and C as well. Re-sealed the entire engines. Same issue: o-rings swelled up and got pushed through the cooling system. Pull the motors, perform a re-seal and drop the engine back in. Not that hard, really.

4-6 hours to pull, 4-6 hours cleaning and replacing everything. Another 4 hours to put the motor back in.

On an 163 ML, I can pull the engine in about 3.5 hours. Once on a stand, the re-seal goes really quick.

Going back to the comments regarding sending these to the junk yard...

Perhaps. But it depends on the overall condition of the vehicle, I suppose. If you have one in very-good to pristine shape (I personally keep my stuff in top shape).. It is hard to replace a good used vehicle for under $3500. And even at that price: you do not know what you are buying or will end up with. Of coarse, if you can do this work yourself - or with the help of a pal who can help you, it should seem to be a no-brainer. But even at a shop that charges upwards of $100/hr - this entire job should not be more than $2500-$3000. And again, I would like to point out: are you seriously going to buy a used car these days for under $3500 that will not need some major work?

Even a $5,000 used car is going to typically cost you a couple thousand in repairs over the first 2-3 years easily. Step up to a $10k used car and if you do not drive too much... You may be okay for a few years with some luck.

But I have seen many early-2000's era benz and beemers that are just absolutely ragged the hell out. People use them, run them into the ground, and once they die - roll them into the pull-a-part. I get it, honestly. But my vehicles often make very long trips into some very remote areas of central Mexico while pulling trailers. I cannot afford to be broke down in such areas and therefore keep my stuff in top-running shape. And buying a new $60k (or more) car - just to pile the miles on - does not make any financial sense.

Once you perform a re-seal, these engines will easily turn out another 150k (or more) miles. So well worth the investment.

My last ML320 cost me: $750. I have put almost 100K on it and invested less than $1500 over 3 years to keep it going.

My last ML500 (2002 sport!) cost me: $240. Woman did not want to pay the $$ to replace the conductor plate. It is at 200k, and after a re-seal, I will get another easy 100k out of that.

I have purchased some amazing E39 BMW 5-series as well: the M62 engines are known for timing chain guide failure. My last 2001 540i (6 speed!!) was less than $600. Over half the E39 and E38 BMW's found at your local pull-a-part are the result of the owner not wanting to pay the shop rate to replace them guide rails.

I patiently wait for you all to "scrap" that junk so I can buy it for next-to-nothing lol. I only wish I had done the same w/ my CLS550 purchase.

I paid WAY too much for that thing.

But back to the original topic here...

This issue affects all the M112 and M113 engines. C-Class, G-Wagon, Roadsters, E-Class.. Those o-rings are slowly absorbing the engine fluids after 20+ years and are all eventually going to swell and cause internal leaks. Just a matter of time now.

 

[deanrantala]

SPECIAL TOOLS NEEDED:

Beyond the basic "engine removal" stuff (cherry picker, engine stand, etc...)

You need the harmonic balancer holder tool in order to remove/install the crank bolt. Can be easily sourced on fleabay and the amazon for about $60.

Some of the early engines did NOT have a hex nut, instead they used a 17MM allen bolt. Not a very common size to find in most allen socket sets. Found online pretty cheap. Autozone also usually stocks a "Special sized allen socket set" for $15 that has 3 over-sized sockets - including the 17mm. If you ever worked on Audis, you likely already have one

If you have an older-model engine w/ mechanical fan clutch (newer cars use electric fan).. you need a fan clutch removal tool. Another $20 or so online.

You will likely want to stick in the new valve stem seals that come with head gasket kits. A cheap $20 "c clamp style" valve spring compressor (ebay or amazon) works just fine for this.

If you are OCD, a parts washer or at least a large plastic tote. Fill it with diesel (or parts washer solvent) in order to get everything clean.

I will snap some pics of my current overhaul shortly.

I have had my 190D restoration project on the back burner for over a year now, but I think I may be doing this to my 2002 ML500 soon. I will likely create a very long "How to remove, re-seal, and replace engine" thread with ton of pics once I start that one.

I no longer have the repair business, and in-fact am doing this current job in the back yard with NO GARAGE and on a sandy yard! Even on the sandy yard, I can have the ML engine out in just under 4 hours. So YES, this can easily be done DIY style.

As soon as the housing market cools down, I hope to purchase a new home WITH a garage, but until then... I am stuck with what I have.

 

[deanrantala]

Dean, I note you are restoring a 190D.

What year ? We had a 1984 190E - the first Benz I bought my wife, back in the day.

Great car - man she loved that thing. But slow as could be. Most gutless 4 cylinder. Probably hampered by the Auto tranny - should have only been offer as a manual tranny.

Gold in color, bought in pristine shape at 90,000 from original owner in about 1992 or so.

He'd drive em 5 or 6 years almost to 100k then sell them.

Paid a reasonable $8500, we drove it for about 5 years & sold it well.

Were it a Diesel, I may have kept it.

Is yours a TD or just Diesel ? Love to hear how you obtained or any details you can share.

Best Regards - David in Texas

Yeah.. restoring it for the second time. Only this time - a comprehensive restoration. Down. To. The. Bare. Chassis.

See the thread here:

1987 190D 2.5 Turbo - Complete Restoration (LOTS OF PICS!)

Ahh... since I have little else to do with my spare time other than sip whiskey and piddle with my cars.. I figured I would share a new project with everyone. So just a little back-story here (all great projects have one, right?).. I did a "so-so" restoration on this car a few years back...

www.benzworld.org

1987 190D 2.5 Turbo (factory). Got 2 of em, actually. Entire story is in the thread.

Between the pandemic and the house I was renting getting sold... that project has been on hold until I get my garage space back.

you can do the job w/o removing the heads but you have to be careful not to damage the head gasket when you reinstall the timing cover.

its a big job. look at tasos mochatos (sp) YT channel. he just did this on a M113k. from what I've SEEN (read as NOT DONE) this would be easier than the guides on the M62s (whoever else here was speaking BMW). if you're a DIY'er and can do this and have the time, tools, talents, etc. I wouldn't hesitate.

Yes, it can be done but... the heads are easy to pull and new gaskets+bolts are cheap. The main reason I personally pull the heads while engine is out: valve stem seals and ability to do a deep clean on all the carbon. Both of these CAN also be done with heads still installed but... why? 10 minutes to remove heads... another 15-20 to install them. I mean - if the engine is out and on the stand. It makes no sense to go out of your way poking around the heads while still installed on the block.

The M62... dear jesus. I love em, but. Always wrenching on them. And yes - the job of JUST timing chain guides/rails could be a bit more involved on those. But keep in mind: you got the VANOS stuff to deal with. You need the flywheel lock, cam locks, etc. While it is broke down - you likely want the VANOS rebuild kit - along with the special VANOS press, etc. And the price of the timing set alone for those is still kind of high to be honest. The M112 and M113 are much more simple engines to deal with.

Most people have never seen a cam/sprocket set that has no splines or keyway. Get the torque spec or alignment just the least bit wrong with those motors (especially the cam!) and it can be a bad day. Plus the electronic thermostats, water-cooled alternators, valley pan, etc. Certainly a lot more to breaking a M62 down.

And don't get me going on the N62. Double VANOS with Valvetronic? Again, I love em... but easy money pits.

I promise to get some pics of the current ML320 I am re-doing up this evening once I get home from the office.

-Dean

 

[deanrantala]

Some quick pics...

Here is my current W163 refresh. Was getting late when I took these photos, so sorry for the poor lighting. As you can see, I am stuck doing this one out in the yard.

Here is the motor. Got it completely tore down. Need to clean it up a little...

Oil pans, timing cover, motor mounts.. Got the lower pan and timing cover clean. Still got to clean up the mounts and upper pan.

THIS will be the next one to get the overhaul. Acquired this one for $240. Woman did not want to put any more money into it. She asked me what I would pay - I told her "scrap value?" she then asked how much. I took the official curb weight and multiplied it by the local pull-a-part yards price-per-pound and it came out to $238. Handed her the cash, and got a clear title. Actually drove it all the way across Aurora and to my brothers house. Ordered a conductor plate, new connector w/ o-ring and 2 gallons of Valvoline MaxLife. After that, I drove this ML just over 100 miles to where I live - where it is parked now. Runs like a top. Needed a few interior pieces, 2 lock actuators, and still needs a window switch module. Nothing that costly.

Sitting under the tarp and to the left is ONE of my 1987 190D's. Stripped down to the bare hull. Soon I will buying something with a garage. The current housing market was just too insane lately for me to even consider a purchase. Once the evictions start, and the free monopoly money stops flowing... house prices will really start to settle - and I will buy.

Yeah.. I buy homes the same way I buy my cars.

 

[deanrantala]

Here is a shot of the timing chain guides...

Notice 2 of the 4 are already cracked?

This is pretty typical of these engines. I would be very surprised to see a 200k+ engine w/ 20+ years that does not have at least one guide rail starting to fracture/crack.

For us BMW guys... this is almost normal maintenance. lol..

Honestly, there is no need to purchase the entire "timing chain kit".

The double-row chain itself is very robust and (under normal conditions) should last the lifespan of the engine.

Likewise, the hydraulic tensioners rarely give any issue and will normally last the lifespan of the engine.

These plastic guides are the only parts that pose an issue after age and mileage. When you do this refresh, get on fleabay and order the guides individually. Much cheaper than trying to find a "set" or "kit". If you scrape around, you can usually get all 4 rails for under $65.

 

[deanrantala]

Spent a little time this afternoon to clean up the engine block a little bit.

Gonna be another week until the head gaskets & valve stem seals come in.

I will try to upload a few more pics as I go along for those who like engine pr0n.

 

[deanrantala]

Finally got some spare time to finish this job up. Figured I would share a few more pics and some notes....

The heads rarely ever give much trouble on these. A quick check with a machinist ruler showed the heads were about as perfectly flat as could be.

I did do a deep clean and re-lapped the valves w/ a drill and some compound.

** I WOULD LIKE TO TAKE A MOMENT TO ADDRESS A SOURCE OF CONFUSION AS WELL **

I have had a few other DIY-ers come over when I had the shop and ask about "sealant around the cylinder head gasket" and the whole "defects in block and/or head" that is mentioned in WIS.

TAKE A LOOK:

This defect is about 1MM deep, and spans several millimeters!

Here is another:

The defect shown above is right between the water jacked and oil passage!

I have ordered BRAND NEW HEADS from MBUSA that had this!

The block can often be found with the same defects. If you see such issues, DO NOT MACHINE THE HEAD. I know.. this sounds nuts but... that is why WIS mentions the sealant around the head gasket.

Here is how I apply the sealant:

I follow the same general pattern on the other side of the HG once I lay it down - just before setting the head.

I usually do not bother w/ the MB sealant (made by locktite). I had a chance to chat w/ some of the guys at Permatex a while back and discovered something: the Permatex "Right Stuff" is the same thing. They are both a "high solids" fast-set RTV that is highly resistant to oil and adheres like crazy to aluminum and magnesium both. I prefer the 90-minute one - gives me a little more working time to assemble everything -VS- the original one that sets in as little as 30 minutes.

MB uses the Locktite one on the production line because: these engines are assembled, filled and run within hours in the factory. They do not have time to wait 24-hours to fully cure.

You are not the factory. And I highly doubt anyone here will be able to re-assemble this engine AND have it back in the car and ready for service in less than 24 hours. Fast-paces shops often need things like valve covers to be ready-for-service in short order - and that is understandable. That said... the "Right Stuff" is a premium RTV that seals these engines perfectly and I have NEVER had a leak from a joint sealed by this stuff. Trust me when I say: I have personally put over 100K miles on [Mercedes] engines sealed by the stuff and never had the first issue.

Anyway... Got her all back together and buttoned up. Full belly of Mobile1 5-40, nearly 3 gallons of G-48 spec coolant (the G-05 works, too). Just stay away from the green. It certainly causes corrosion buildup around all the gaskets, orings and where the hoses connect to the nipples.

Took it for a 20 mile trip this evening - smooth as butter.

 

[deanrantala]

G'day @deanrantala,

I wanted to say thank you for your help. I own a 2005 ML350 with a W163/722.6 and had the dreaded coolant/oil soup mix. Upon investigation and removal of the water pump, i managed to feel around for the non existent seals and well... the next steps were obvious.

Fast forward several months later and my ML is rebuilt and purring like a kitten with an all new seals kit throughout.

I do have one last question... What would you recommend is the best way to clean out the coolant system. I still have some residual oil kicking around in there and am curious as to what is the best way to clean out the system without destroying all my hard work?

I have read everything from expensive coolant flushes to dish washing detergeant will work. Deagreaser mixed with water. And clothing laundry detergeant. It is a maze of pitfalls that i would rather avoid. Any advice is appreciated.

I have pressure tested the radiator. It holds 15psi easily, so I am fairly confident its residual oil. (Also test drove for an hour and neither the oil/PS fluid/ATF dipped at all). Which i would have expected to happen if there was a leak of some form...

Any help would be appreciated.

And thank you again. your post answered and solved my problem beautifully. Thank you

Adam

Any good engine flush ($8-$12 should be sufficient. If you had a LOT of contamination, it may take 2 or 3 flushes.

Also, some responsibility falls on the person or shop who performs this repair - especially when you have a LOT of contamination. It really helps when the engine is out and you have everything broken down to perform the following:

• Manually flush out the heater core with a garden hose. Pouring a bucket of very HOT water and lots of Dawn Platinum into one end of the hose followed by a good rinse-out with the garden hose. Repeat this 2 or 3 times.
• Do the same with each hose. Submerge each hose in a large bucket/pale of scolding hot water w/ Dawn and squeeze the hose (working the soapy water around). Rinse completely.
• While heads are removed, it is very easy to clean 99% of all the water passages in the block AND head with soapy water and a bottle brush.
• Same goes for radiator.. hot soapy water w/ dawn.

Obviously, if you already have the engine re-assembled - some of these steps will not be valid. But some of it you CAN do....

• Drain the coolant
• Remove upper and lower coolant lines from radiator
• Remove 2 coolant lines going to/from on heater core
• Flush radiator and heater core each with hot soapy water. Have a buddy hold their hand over lower outlet and pour the hot soapy water into the top by bending the hose upwards. Fill, drain, rinse with garden hose. Repeat. Do the same for the heater core. You can unhook the 2 lines that come to/from the heater core from the back of the driver-side cylinder head and the circulation pump (pass side fender). Hold one line upwards and use a large funnel to pour the hot water into. Rinse completely with garden hose.
• After both radiators are completely flushed, fill with water and flush solution. Regardless of what the flush bottles say, drive the thing a good 40-80 miles. Do this when you know there is no freezing weather expected. You should have very little (if any) contamination after doing this twice. You may find virtually no contamination after just a single flush.

Some other notes on the flush:

• Stick with Dawn Ultra or Platinum. The Ajax and other brands just do NOT cut oil like Dawn - trust me on this.
• Be sure to flush the dawn out very well. Also note: the Dawn is only for the manual flush - DO NOT PUT IT IN YOUR ENGINE AND RUN THE ENGINE.
• Stay away from degreasers. Most engine degreasers have Sodium Hydroxide (a.k.a. Caustic Soda). If you are un-familiar with Sodium Hydroxide, let me explain what it is: a mild acid that reacts rather aggressively with aluminum and is also rather harsh on seals/orings. It is also the main active ingredient of Oven Cleaner. Depending on which degreaser you are talking about (one of my favorite is the Zep industrial).. they will even turn aluminum a darkish color due to oxidation.
• Coolant tanks are cheap. Spend the $20 for a new one AFTER you are done flushing the system. The tank typically does not get enough "flow" to really make any amount of flushing effective. Again, the tank is dirt cheap.
• No need to change the thermostat if it has recently been replaced. However, the o-ring for the thermostat is only a dollar or two. So if you pull the thermostat and flush the block out with fresh water, be sure to use a new o-ring. Again, they are dirt cheap - do not risk it.
• While the Zerex G-05 and MB original fluids are excellent choices - do NOT be afraid to head to Wal-Mart. They now sell a generic version of the Teal-colored (branded as "Teal Color, For European vehicles") that is the same exact chemical that was originally used on that vehicle. It is only $10 a gallon and pre-diluted. You only need 3 gallons to fill a bone-dry M112 and right at 3 gallons to fill a bone dry M113. Stay away from the generic green stuff. While it will not cause catastrophic issues, it DOES allow mild corrosion at various connections and seal points throughout the coolant system on these vehicles. You will NOT see this issue with the generic teal-colored stuff, zerex g-05 or official MB fluid (either the older blue OR golden colored).
• The hose clamp for the upper hose is very deceiving. If it is not perfectly straight around the neck of the thermostat, it will slowly dribble. I know this sounds easy, but trust me - very easy and common mistake to not get that clamp perfectly flat around the neck.

Hope this helps.

-Dean

 

[deanrantala]

While the MB flushing agent is a fine choice, I would like to point out:

Depending on how bad the contamination is, no amount of flushing agent is always going to get the job done. Other times, it may - but will easily take several rounds.

Also remember this: while technically you could run a flushing agent through the system 4 or more times, what is your time worth?

At the dealership, MB often will NOT FLUSH/CLEAN certain components out if the contamination is severe enough. They replace. The components in particular here are: radiator, heater core, and possibly some of the hoses. Why? TIME.

Each flush requires you:

1. Fill a cool engine with fresh water
2. Add solution
3. Start engine and bring up to temp
4. Wait several minutes
5. Turn off
6. Wait several minutes
7. Drain
8. Inspect
9. Hope it is clean, if not - repeat.

If you need to repeat this more than a couple times (as could be the case in moderate-to-severe contamination), you can easily spend many hours on this.

Now - I would like to point out that my initial flushing advice is based on the assumption you have moderate-to-severe contamination. For those who have not worked around a repair shop and seen first-hand what "moderate-to-severe" means, I will explain.

When you have a large (1" or thicker) layer of emulsified oil laying in the bottom of the of your expansion tank. Perhaps a solid quarter to half-inch layer built up around the entire inside of the radiator. Or the coating of emulsified oil along the inside of your hoses is 2 or 3 times thicker than the wall of the hoses themselves... If this is the case, forget about a flushing agent as step-1. Much more time-efficient and effective to break out the good-ol soapy water and give it a proper cleaning. If you have never seen a truly "contaminated" system, imagine a medium-brown substance with the consistency of pudding. Sometimes, it can be so bad to the point of almost completely blocking.

If all we are talking about here is a light residue and some signs of a light film floating along the top inside the expansion tank - skip the comprehensive cleaning I outlined above. Use your choice of flushing agent. Honesty, the Prestone stuff is 1) just as effective, 2) available at any walmart, or parts house and 3) plenty safe and poses zero risk of any damage to your MB cooling system. If you feel better using the official MB-branded stuff, that is absolutely fine.

One last point here regarding the use of distilled water (I know the purists are just boiling over by now)... Tap water from the garden hose is not going to be in your cooling system long enough to cause any "deposits" or damage. And on the topic of the flushing water for a manual clean/flush - I want to point out again... The HOTTER the water, the better. If the contamination is really bad (lots of the brown pudding-like paste stuck everywhere), lot's of hot water is the key to washing it out. Also note that when the contamination is this bad - a simple flushing agent would be foolish since you may wash/shift large chunks of this emulsified oil into other parts of the cooling system. Which again - is why I prefer the manual method while the engine is out or when I am doing a head gasket job that suffered severe contamination.

But again... if all we are talking about is light residue... A simple flush is just fine. The cheaper Prestone is more than effective, but use the MB stuff if that is your preference. And do NOT be afraid to drive around town a day or two with it in the system to ensure it really loosens up the residue if the residue was slightly nearing the "moderate" side.

Cheers!