Reinstall Cylinder Head sequence on OM606.962 - Page 2 - PeachParts Mercedes-Benz Forum

kwmccauley · #16 06-28-2012, 03:59 PM

Hein,

How much history do you have with the car? Owned it since new? Has the cylinder head ever been off the engine before?
If this is the first time the head is being removed and the head bolts now in there were originally placed there by the folks in the factory then your torque estimate makes sense to me. I do recall being quite worried when I loosened the first head bolt. It made a snapping noise and I thought the bolt or the 10mm tool had sheared. The good news is it was the sound the bolt made when it loosened after being in the head for 12 years and 260k miles.

If it would help you, I can attempt an experiment with the original head bolts which I still have. I'll have to think about how to do this but I will attempt to lock the bolt in a large vise and go to increasing levels of torque until the bolt fails if I can make it fail before the 10mm XZN tool fails. The trick will be estimating the torque to failure since I do not have a direct way of measuring it.
Ken

windjammer · #17 06-29-2012, 10:37 AM

Finally got the head bolts all loose with a 2' extension. This Stahlwille tool must be real quality--why not since it costs a lot. Baumtools sells the thing for $19.38 +16.02 shipping. Ordered via Peachparts it costs nearly 45 bucks! Just can't escape ripoffs There must be a way ordering direct.

windjammer · #18 06-29-2012, 11:10 AM

Quote:

Originally Posted by kwmccauley

Hein,

How much history do you have with the car? Owned it since new? Has the cylinder head ever been off the engine before?
If this is the first time the head is being removed and the head bolts now in there were originally placed there by the folks in the factory then your torque estimate makes sense to me. I do recall being quite worried when I loosened the first head bolt. It made a snapping noise and I thought the bolt or the 10mm tool had sheared. The good news is it was the sound the bolt made when it loosened after being in the head for 12 years and 260k miles.

If it would help you, I can attempt an experiment with the original head bolts which I still have. I'll have to think about how to do this but I will attempt to lock the bolt in a large vise and go to increasing levels of torque until the bolt fails if I can make it fail before the 10mm XZN tool fails. The trick will be estimating the torque to failure since I do not have a direct way of measuring it.
Ken

Hi Ken, forgot switching to Page 2. I mentioned that I finally removed all head bolts. Your suggestion is going above and beyond your "duty" you are just great to have you in our community. On another forum there is a guy who offered step by step guidance to head removal, he quit because he allegedly received hate mail for doing. It's hard to believe but if it is true its a real shame. You are right, when the torque breaks it has a real hard, metallic sound and for a moment one thinks its the tool or the bolt. I bought the car last Feb. with 122 k on it. Looks like brand new in and out, paid 10K for it and is worth every penny. There are no indication it was ever touched mechanically. It came with no service records and so performed all the things what is listed under Service B. All came to a screeching stop when this NUT writing the report though he new it all. Finding out the hard way that a lot is written in this wonderful forum for the asking--the hard part is getting an answer. Anyway, Ken, my hearty thanks. Cheers, Hein

PS. one more question: How heavy is the head, and how about the plastic top guide does it remain where it is after removing the bolt?

kwmccauley · #19 06-29-2012, 04:58 PM

Hein,

Glad to hear the 26 head bolts came out for you!

When I shipped the head to the shop that did the valve and related work for me the shipping weight was 54 pounds. This included the cylinder head, box and packing material. Not sure how you plan to lift the head off of the block in terms of exhaust manifold attached or not. If the exhaust manifold is attached your lift will exceed 54 pounds. Dealing with the weight was not such a challenge. It was more of an issue of reaching over the front fender to do the lift. That is why I used an engine hoist which was really overkill for the amount of weight to be lifted.
Also, if you have not yet done this I recommend raising the hood to the vertical position by pressing the tabs near the hinges. It makes for much improved access to the engine bay.
Hope you enjoy your weekend!
Ken

kwmccauley · #20 06-29-2012, 05:28 PM

Hein,

I do not know what this question refers to:

"...how about the plastic top guide does it remain where it is after removing the bolt?"

Can you provide a little more information about it and I will attempt to answer?
Thank you,
Ken

windjammer · #21 06-30-2012, 10:18 AM

Hi Ken, the guide I'm talking about is the one that is prominently sticking out of the head and in which the chain runs. The bolt holding it in place is also holding the plastic balance on which the chain tighteners are anchored, but since the chain is fully enclosed by this guide I assume that the bottom of it is part of the engine block and remains there. Another thing you paid attention to that you placed a new O-ring on the pipe that exits the cooling pipe. What I see is a plastic? pipe that enters the head surrounded by a mounting flange with a screw hole but no clamp or anything. Is that right? Since that pipe eventually connects to a rubber hose do I disconnect at the juncture and then wiggle the pipe out of the head? Question, question, please don't give up on me. Have a good day, Hein

P.S. Another thing, the bolt I mentioned holding the balance Took me at least 2 hours to work it loose and in the process mangled the bolt with a vice-grip to such an extend to be useless. Would you know the part #?-thanks

kwmccauley · #22 06-30-2012, 11:22 AM

Hein,

Attached are four files which show the drawings and parts lists for the cooling system and timing chain system.
The plastic top guide that you mentioned is open on the back side and does not fully enclose the chain. I think all of the other parts you mentioned are pictured in the drawings and have corresponding part numbers on the parts lists.
The "bolts" that you mentioned are probably the internally threaded pins. Is this correct? If that is what you meant, there is a puller tool to pull those out. I believe it is threaded 6mm x 1 (not 100% certain of thread). You can also make a puller out of an appropriately threaded bolt a socket and some washers. put the bolt through a few washers that are larger diameter than the socket opening, pass the bolt through the socket (used as a spacer and bearing surface for your improvised puller) and thread the bolt into the exposed end of the internally threaded pins (#83 and #86 on the timing system parts drawing attached). Tightening the bolt pulls the pins from the block and frees the chain guide.

As for the coolant pipe with O-ring at the left rear of the cylinder head (pipe is #179 on the coolant system drawing), I did disconnect the flexible hose attached to it. As I recall, I think I wiggled the rigid pipe out of the head after the head was removed from the block.

I highly recommend that you sign up at this URL for the FREE subscription to all of the parts drawings and part number listings for any Mercedes that you own. It has been a great help to me EPC-net Online
The information is VIN number specific and you enter the VIN(s) when you register.

Happy to help so don't hesitate to ask any questions that may come up.
Ken

kwmccauley · #23 06-30-2012, 11:39 AM

Hein,
While you are doing all of the work on your car, it might be a good idea to proactively replace the coolant pump. Many of the 1999 cars had issues with the coolant pump impeller separating into multiple pieces. Attached is a photo of what happened to mine. This occurred at 226k miles in June 2009.
Also, since the car was built, the thermostat housing was updated so you would need a new thermostat housing if you are replacing the thermostat at the same time as the coolant pump.
Of course, with the miles you have on your car the coolant pump that you have may serve you well for many more years.
Ken

kwmccauley · #24 06-30-2012, 11:56 AM

Hein,
One more thought on the improvised puller described above.....if you go this route please be sure to use a hardened automotive metric bolt. Either an 8.8 or 10.9 graded bolt should be fine for the M6 x 1 bolt. A lower grade bolt may shear off or experience stripped threads when pulling the pins.
Ken

windjammer · #25 06-30-2012, 03:52 PM

Hi Ken, many thanks, as of the threaded pin I'm well informed because all the pins on the old M. Diesels have that arrangement. Truth of the matter, the bolt was frozen tied, I wiggled it loose with a vice-grip. The bolt arrangement would never have worked originally until the very end when I pulled the pin after broken the grip. Tomorrow morning the head will be out. As mentioned, I ordered a new head paid by check on a Friday. Over the weekend I changed my mind and cancelled. No time clearing the check. However, the dealer was most understanding. After checking out the head I will know more. If a new one is necessary I must eat it up. All the best, Hein

windjammer · #26 07-01-2012, 10:28 AM

Hi Ken, I build a lifting device like you mentioned. Works fine. Frankly, the only thing that is holding up removing the head is the bolt holding the bottom of the plastic guide. The head is high enough for a clear view and what I see is nothing but a hole--no thread that would indicate a bolt to be pulled. You and anyone else must have come to that point removing the bolt otherwise there is no way separating the head from the engine unless one is prepared splitting the chain? Perhaps you or anyone else reading the post has an answer. As always I appreciate all advice big or small. Cheers, Hein

windjammer · #27 07-03-2012, 01:35 PM

There was no way removing the pin via threaded rod and spacers. Had to deepen the hole and thread then drilled the pin out past the casing. It then came easy. The head is now on the workbench to work on.

windjammer · #28 07-08-2012, 03:04 PM

Quote:

Originally Posted by kwmccauley

Hein,
While you are doing all of the work on your car, it might be a good idea to proactively replace the coolant pump. Many of the 1999 cars had issues with the coolant pump impeller separating into multiple pieces. Attached is a photo of what happened to mine. This occurred at 226k miles in June 2009.
Also, since the car was built, the thermostat housing was updated so you would need a new thermostat housing if you are replacing the thermostat at the same time as the coolant pump.
Of course, with the miles you have on your car the coolant pump that you have may serve you well for many more years.
Ken

Hi Ken, just to let you know what I'm doing. The head is on the bench. Finally got all the glow plugs removed; even the one I had fouled up badly to the extent that I ordered a new head but had changed my mind over the weekend and cancelled--the weekend saved the transaction from going through. Anyway, the operation I did to save the head I will compose in detail and will send it to you. Removed the prechambers and it is amazing to see soo much carbon crystals accumulated on the bottom. Scraped and polished it all out. Had to buy a bunch of special tools which cost a lot of money. But, I'm pleased and feel good about it. Perhaps you be so good and send me the torque of the prechamber ring, according to the old Diesels it is 127+27Nm? Hope you have it cooler your way, we are miserable--greetings, Hein

kwmccauley · #29 07-19-2012, 08:24 PM

Hein,

Sorry I missed your earlier post. Usually I get an e-mail notification when there is a new post to a subscribed thread. It did not happen this time.

I have the torque on the pre-chamber rings as 130 newton-meters or approx. 98 ft-lbs.

Hope all is going well!
Ken

kwmccauley · #30 07-19-2012, 08:26 PM

Hein,
I am curious if you decided to do the valve work yourself. If so, is this what the special tools were for?
Thank you,
Ken