Reinstall Cylinder Head sequence on OM606.962

[kwmccauley]

On Friday I will begin reinstalling the cylinder head on my 1999 E300 turbodiesel. I have an engine hoist and will use it to slowly lower and maneuver the head on to the new head gasket. If anyone has done this job please let me know if you installed the exhaust manifold on the head first or installed the head first then bolted on the exhaust manifold.
It would seem easier to install the head on its own and add the exhaust manifold later. My only concern is clearance between the head and the turbo's three bolt mounting flange once the head is on the block.
Thanks,
Ken

[KarTek]

Ken, I've had the turbo and manifold off several times and it's really no problem. The oil feed line is a little difficult and you have to get at at least one turbo mounting bolt from the bottom but other than that, it's OK.

[kwmccauley]

KarTek,
Many thanks. Will go at it with the head only and bolt on the exhaust manifold later once the head bolts are in before I go through the full torque procedure on the 26 head bolts.
Ken

[warmthesea]

I have removed the cylinder head off of my 1999 E300TD, OM606. Glow plugs #1 and #6 were frozen in place. I successfully used the drilling, tapping and extracting procedure on #1, but #6 didn't work out as well. After much anguish and pain I decided to remove the head. It is currently at Vellios Machine Shop in Lawndale for a valve job while it is out. The engine has 214,000 miles. This is my first time and I was hoping to find some advice for putting it all back together. Any advice, no matter how small or trivial would be so appreciated!
Thank you,
Dale

[kwmccauley]

Dale,

Good timing. I just completed this job and started the engine yesterday. I am happy to pull some notes together for you and other readers. To help me focus it on your project can you tell me if you plan to do any other work while you have the top end of the engine apart? For example, in addition to the valve job, I replaced the timing chain, tensioner and guide rail. Also did the 6 hard plastic fuel lines, fuel shutoff valve (w/O-ring) and had new nozzles installed in the fuel injectors and got them balanced for correct pop-off pressure. If you are focused mainly on the head replacement I will focus the notes in that area.
Thanks,
Ken

[warmthesea]

Ken!
Thank you so much!
I do hope things went well for you when you started her up again.
Hoping the same for my little unplanned fix-it project
---> http://www.youtube.com/watch?v=zyScW8gAFjM

In response to your query, I'm most concerned with being able to put her back together properly. I'm not planning on replacing the timing chain, tensioner, guide rail, aside from new guide rail pins. Those things seem fine to me, as well, that stuff seems tricky!
I am replacing gaskets and o-rings that i've found taking things apart. At the same time I am trying to find a fuel leak coming from somewhere around, or from the injection pump. I'm afraid it is leaking from the pump itself somewhere, can't exactly tell without being able to start it. I have in the past, recently replaced the plastic hoses and 0-rings with viton, the seals that connect the hard lines to the top of the pump have all been done and all those seem just fine. So if there is also any advice available for fuel leaks about the injection pump, but below the top of it, I would be most grateful!
Thank you again Ken! and all PeachParts Shopforum users!

[EdzBenz]

Thank you for the posts and suggestions on the head gasket reassembly. This is a project I plan to tackle in the next few months and I'm reading up on anything I can find for the project... especially "other" items I can do to the engine while I'm at it.

[kwmccauley]

This job was just completed on Sunday, 2/20. Performance is great and after 100 miles it seems all of the fluids are staying where they are supposed to be.

An engine hoist or some type of lifting equipment is highly recommended to do this job. The cylinder head with exhaust manifold mounted is not all that heavy but the ability to maneuver the head and position it properly on top of the new head gasket the first time is vastly improved with a hoist. It also helps in getting the turbocharger mounting studs to line up with the mounting holes in the exhaust manifold.

To attach the hoist to the cylinder head I made two identical fixtures of plywood drilled on each end with a hole to fit the 7mm bolts that will fit the threads of the head. Into the top of each of the two wood blocks was a heavy duty screw-eye to use as an attachment point for the hoist chain (S-hooks attached the chain to the screw-eyes). Mercedes has very nice aluminum fixtures for this but the cost and lead time did not make sense for me on what I hope is a once in a lifetime project. The MB aluminum fixtures are part # 119 589 01 40 00. They are called cylinder head lifting brackets.
The wood blocks worked just fine.

I used the parts system on EPC to identify and get all of the parts I needed in advance. Also used AllDataDiycom (best $16.95 I ever spent) for procedures, torque values, etc. as well as thoroughly researched several forum resources before doing this job. This forum and others were very valuable sources. Thanks to all past contributors!

Some cautions worthy of note:
[*]clean the engine block gasket mating surface as thoroughly as possible being careful not to scratch the surface[*]avoid holding parts over the opening to "the abyss" where the timing chain resides. If you drop something down there it is not trivial to recover.[*]Treat the camshafts with care and follow the torque procedure when replacing the 7 bearing caps. The caps are labeled 1 through 7 on the passenger side top of each the bearing caps. #1 goes at the front of the engine with #7 at the rear. The camshafts are hollow and susceptable to fracture.[*]Clean out the 26 cylinder head bolt holes. I used a compressed air blow gun with a rag around the top of the bolt holes to keep oil from getting where I did not want it.[*]After the cylinder head is back on the block and properly torqued down in the recommended bolt specific sequence of 15nm, 35nm, turn 90 degrees then wait at least 10 minutes and turn another 90 degrees, install the six new seal rings and bolt down the camshaft housing with two 7mm x 41mm bolts. These are a very unusual size. I used two of the cam bearing cap bolts with washers to take up the excess length. This keeps the cam housing from moving around as you replace the cams. This is VERY important. Remove the two bolts when you need them to install the last cam bearing cap.

I used new head bolts (26 pieces). If you plan to reuse the old ones measure them to make sure they are still in spec. The long bolts can be a maximum of 117mm. The short bolts can be a maximum of 104mm. The new bolts are 2mm shorter than these maximum length specs.

In terms of the fuel leak that you asked about, one place I had a leak previously was at the fuel shut-off valve which bolts to the left side of the injection pump. The fuel shut-off valve is part number A 000 078 44 49. The O-ring seal on the back of it where it mates to the Injection Pump (IP) is part # A 021 997 75 48. The other place is at the O-ring on one of the six hard plastic fuel lines. It sounds like you already took those out of the equation by replacing them recently.

Where the coolant pipe exits the left rear corner of the cylinder head, I installed a new O-ring prior to reassembly. This O-ring is part # A 012 997 51 48.

Ordering the cylinder head gasket kit simplified some of the parts ordering since it contained many of the other gaskets and seals required. For example, in addition to the head gasket, the kit included the intake manifold gasket, exhaust manifold gasket, O-rings for the so called "bushes" of the trim cover. These "bushes" are the risers or stacks that surround the fuel injectors when installed. The head gasket kit also included the fuel injector heat shields and the six O-rings that seal between the top of the cylinder head and the camshaft housing.

If your cylinder head was resurfaced by the machine shop ask them what thickness of material they removed. This will determine of you can use the standard 1.65mm thick head gasket or need to order a thicker "repair size" which is 1.85mm.

ONCE THE TIMING CHAIN GUIDE RAIL PINS (2) ARE REINSTALLED IN THE HEAD, STUFF CLEAN CLOTHS INTO THE OPENING TO PRECLUDE ANYTHING FROM FALLING INTO THE ABYSS MENTIONED ABOVE.

Spend the most time and focus the most care on proper camshaft alignment and timing. The crankshaft should still be at TDC from when you started the job. The exhaust cam dot at the 3 o'clock position should meet up exactly with the intake cam dot at 9 o'clock AND the #1 bearing cap bore should line up with the hole in the intake cam gear. If you marked at the start of the job which tooth on the exhaust cam drive sprocket matched up with which link on the timing chain it should be straightforward to bolt it up in the right position to maintain the timing as it was before.

I installed all new fuel return lines. The original fabric covered hose part number is A 605 078 05 81. You will need to cut this into 6 pieces. One piece is 340mm for the return line from injector #1 to the fuel return line fitting at the fuel filter, the other five are 165mm to daisy chain between the fuel injectors. The stub (cap) at fuel injector #6 is part # A 605 070 00 55.

Get some new fuel line clips that hold the rigid fuel pipes (6) to the valve cover and cylinder head mounted brackets. The clips are part # A 603 078 01 41. I replaced all 7 pieces. Torque on the rigid fuel lines is 23Nm on the injectors and at the IP.

Also installed a new O-ring inside the EGR valve prior to reassembly. This is part number A 606 997 06 45.

Check the oil and refill the coolant. One thing I did was leave the top off of the coolant expansion tank to keep any pressure from building up in the cooling system until after the new head gasket had a chance to get used to its new home. This may be unnecessary but it gave me some peace of mind.

When you are ready to start it up for the first time, it will help reduce cranking time if you fill the pre-filter and final fuel filters with fuel. As you know, there is no priming method on this engine and it takes a while for the fuel pump to purge the air from the system. My car was out of commission for some time so I brought the battery up to a full charge while I was putting the engine back together. This helped when it was time to crank and purge the air from the fuel system.

I'm sure there are some points I did not think of in this summary so please ask and I will answer the best I can.

Best wishes for success. It sure does sound sweet when that engine fires up!
Ken

[windjammer]

Originally Posted by kwmccauley

This job was just completed on Sunday, 2/20. Performance is great and after 100 miles it seems all of the fluids are staying where they are supposed to be.

An engine hoist or some type of lifting equipment is highly recommended to do this job. The cylinder head with exhaust manifold mounted is not all that heavy but the ability to maneuver the head and position it properly on top of the new head gasket the first time is vastly improved with a hoist. It also helps in getting the turbocharger mounting studs to line up with the mounting holes in the exhaust manifold.

To attach the hoist to the cylinder head I made two identical fixtures of plywood drilled on each end with a hole to fit the 7mm bolts that will fit the threads of the head. Into the top of each of the two wood blocks was a heavy duty screw-eye to use as an attachment point for the hoist chain (S-hooks attached the chain to the screw-eyes). Mercedes has very nice aluminum fixtures for this but the cost and lead time did not make sense for me on what I hope is a once in a lifetime project. The MB aluminum fixtures are part # 119 589 01 40 00. They are called cylinder head lifting brackets.
The wood blocks worked just fine.

I used the parts system on EPC to identify and get all of the parts I needed in advance. Also used AllDataDiycom (best $16.95 I ever spent) for procedures, torque values, etc. as well as thoroughly researched several forum resources before doing this job. This forum and others were very valuable sources. Thanks to all past contributors!

Some cautions worthy of note:
[*]clean the engine block gasket mating surface as thoroughly as possible being careful not to scratch the surface[*]avoid holding parts over the opening to "the abyss" where the timing chain resides. If you drop something down there it is not trivial to recover.[*]Treat the camshafts with care and follow the torque procedure when replacing the 7 bearing caps. The caps are labeled 1 through 7 on the passenger side top of each the bearing caps. #1 goes at the front of the engine with #7 at the rear. The camshafts are hollow and susceptable to fracture.[*]Clean out the 26 cylinder head bolt holes. I used a compressed air blow gun with a rag around the top of the bolt holes to keep oil from getting where I did not want it.[*]After the cylinder head is back on the block and properly torqued down in the recommended bolt specific sequence of 15nm, 35nm, turn 90 degrees then wait at least 10 minutes and turn another 90 degrees, install the six new seal rings and bolt down the camshaft housing with two 7mm x 41mm bolts. These are a very unusual size. I used two of the cam bearing cap bolts with washers to take up the excess length. This keeps the cam housing from moving around as you replace the cams. This is VERY important. Remove the two bolts when you need them to install the last cam bearing cap.

I used new head bolts (26 pieces). If you plan to reuse the old ones measure them to make sure they are still in spec. The long bolts can be a maximum of 117mm. The short bolts can be a maximum of 104mm. The new bolts are 2mm shorter than these maximum length specs.

In terms of the fuel leak that you asked about, one place I had a leak previously was at the fuel shut-off valve which bolts to the left side of the injection pump. The fuel shut-off valve is part number A 000 078 44 49. The O-ring seal on the back of it where it mates to the Injection Pump (IP) is part # A 021 997 75 48. The other place is at the O-ring on one of the six hard plastic fuel lines. It sounds like you already took those out of the equation by replacing them recently.

Where the coolant pipe exits the left rear corner of the cylinder head, I installed a new O-ring prior to reassembly. This O-ring is part # A 012 997 51 48.

Ordering the cylinder head gasket kit simplified some of the parts ordering since it contained many of the other gaskets and seals required. For example, in addition to the head gasket, the kit included the intake manifold gasket, exhaust manifold gasket, O-rings for the so called "bushes" of the trim cover. These "bushes" are the risers or stacks that surround the fuel injectors when installed. The head gasket kit also included the fuel injector heat shields and the six O-rings that seal between the top of the cylinder head and the camshaft housing.

If your cylinder head was resurfaced by the machine shop ask them what thickness of material they removed. This will determine of you can use the standard 1.65mm thick head gasket or need to order a thicker "repair size" which is 1.85mm.

ONCE THE TIMING CHAIN GUIDE RAIL PINS (2) ARE REINSTALLED IN THE HEAD, STUFF CLEAN CLOTHS INTO THE OPENING TO PRECLUDE ANYTHING FROM FALLING INTO THE ABYSS MENTIONED ABOVE.

Spend the most time and focus the most care on proper camshaft alignment and timing. The crankshaft should still be at TDC from when you started the job. The exhaust cam dot at the 3 o'clock position should meet up exactly with the intake cam dot at 9 o'clock AND the #1 bearing cap bore should line up with the hole in the intake cam gear. If you marked at the start of the job which tooth on the exhaust cam drive sprocket matched up with which link on the timing chain it should be straightforward to bolt it up in the right position to maintain the timing as it was before.

I installed all new fuel return lines. The original fabric covered hose part number is A 605 078 05 81. You will need to cut this into 6 pieces. One piece is 340mm for the return line from injector #1 to the fuel return line fitting at the fuel filter, the other five are 165mm to daisy chain between the fuel injectors. The stub (cap) at fuel injector #6 is part # A 605 070 00 55.

Get some new fuel line clips that hold the rigid fuel pipes (6) to the valve cover and cylinder head mounted brackets. The clips are part # A 603 078 01 41. I replaced all 7 pieces. Torque on the rigid fuel lines is 23Nm on the injectors and at the IP.

Also installed a new O-ring inside the EGR valve prior to reassembly. This is part number A 606 997 06 45.

Check the oil and refill the coolant. One thing I did was leave the top off of the coolant expansion tank to keep any pressure from building up in the cooling system until after the new head gasket had a chance to get used to its new home. This may be unnecessary but it gave me some peace of mind.

When you are ready to start it up for the first time, it will help reduce cranking time if you fill the pre-filter and final fuel filters with fuel. As you know, there is no priming method on this engine and it takes a while for the fuel pump to purge the air from the system. My car was out of commission for some time so I brought the battery up to a full charge while I was putting the engine back together. This helped when it was time to crank and purge the air from the fuel system.

I'm sure there are some points I did not think of in this summary so please ask and I will answer the best I can.

Best wishes for success. It sure does sound sweet when that engine fires up!
Ken

Hi Ken, I consider myself very lucky having found your post. Had to purchase a new cylinder head (99 300dt) and have to transfer valves and pre-chambers from old to new. Did you ever do a job of this sort? If you did perhaps I could ask for info ? Hein

[kwmccauley]

Hein,
I did have a valve job done on the cylinder head but I did not do that work myself. The shop in Wisconsin (Black Forest) that did the work removed all 24 valves to replace the valve guides and seals and check to confirm that all valves were straight.

As for the pre-chambers, this requires some special tooling. FIRST- the glow plugs must be removed before attempting to remove the pre-chambers. After the glow plugs and fuel injectors are removed, the threaded retaining ring holding in the pre-chamber must be removed. This can be accomplished with Sir Tools #M0009 which is a splined socket. Once all 6 rings have been removed, you will need another tool to thread into the top of the pre-chambers. Sir Tools #M0046 works for this purpose. Into the top of the M0046 you need to thread a slide hammer which exerts the necessary upward force to remove the pre-chambers. The guys at Peach Parts were very helpful when I needed to round up parts.

Hope this helps. Let me know if you want photos and I'll look through what I have on my computer that did not crash since doing the work back in early 2011.

If you don't mind me asking the question, what happened to the cylinder head that caused you to get into the project of replacing it?
Ken

P.S. My 1999 E300 Turbodiesel now has 46,000 miles on it since the February 2011 posting above. Running well.

[windjammer]

Hi Ken, sure appreciate your quick reply. Thank you! As to your question: by drilling out #1 plug I got off course and eventually drilled right into air duct. I was sure that the plug is at right ankle to the block it isn't, it is somewhat to the left. I ruined a perfectly running engine and i could kick my butt for being so absolutely stupid.So much for that. I understand all you are writing. One quick question: Today I received the 12pt socket to remove the head bolts, put a 18" bar on it and tried. I couldn't budge with all my power--and I'm no weakling believe me. In fact I was afraid I my twist the bit or strip the bolts--I tried more than one! Is that normal? Tomorrow I get a 2' extension pipe but afraid I may just do that. I have a lot of experience with Mercedes Diesel, Have a 615 in the boat for the past 40+ years.All is so different on the new Diesels. Looking at the valves I'm lost; somehow The spring and valves have to come out but all I see on top the valves is something I can't make sense off--perhaps another special tool? I must pluck on and any help is appreciated. Best regards, Hein

[kwmccauley]

Hein,

There is a special tool recommended for the valve work. I do not know that it is REQUIRED but it is recommended. I will look for a picture of it and send as an attachment later tonight. Basically what it does is anchor to a location on the head and provide a fulcrum for the lever arm to compress the valve spring such that one can then remove the keeper/retainer.

As for the head bolts, I remember that I was also concerned about how much force I had to exert to remove them. Fortunately, the 1/2" drive XZN or "DoubleHex" or "Triple Square" 12 point 10mm tool was made by Hazet in Germany. I believe I used it with my 18" breaker bar to loosen the head bolts. In my case nothing broke in terms of head bolts or tools but I did have to apply a lot of force to get the head bolts started on the way out out of their place in the head.

Back to you later with more information about the valve tool.
Best wishes,
Ken

[kwmccauley]

Hein,
Perhaps the three attached files will be helpful to you on how to remove the valves from the old cylinder head. I did not do the valve job on my OM606.962engine so can't offer any practical advice based on first hand experience.
Best,
Ken

[kwmccauley]

Hein,
Two more files attached on valve detail and parts list.
Please let us know how it all goes.
Ken

[windjammer]

Tks Ken, everything is helpful. Back to last email talking about the excessive force required (in my opinion) to loosen the head bolts is there a danger stripping or breaking the bolt or wrench? Did you losing yours with a bar or impact wrench. Looking in the manual for my old Diesel, the final setting for hex bolts are 74 ft/lbs--for 12pt 30/50/-90deg,90deg--what I assume to be equal 74ft/lbs and conforms to the new Diesel. Certainly not excessive. Your opinion--Hein