While taking the cylinder head off my 3.0 M103 engine i broke the very top half of the outer timing chain guide rail (the more straight one),,, can someone tell me how critical the top of this rail is for proper operation and also if it does in fact need to be replaced, what steps are involved, how much time am i looking at?? The head will be ready tomorrow and i wanted to just get it back and throw it on and go.... Also does anyone know if i should drive it under a certain speed for a certain amount of time after the head gasket is replaced to let it seat properly, or can i just drive it like normal??

I would suspect that if you broke it removing the head then they are pretty brittle. If it were my car or one I am working on for one of my friends then I would suggest removing the front cover and replacing all the guides. You will be surprised how worn the oil pump chain tensioner guide gets.
How many miles are on it?

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Jim

there is 189,000..... what kind of work am i looking at to replace all of this stuff??

Evan - to me it is not much to it. The hardest part (if you don't have the flywheel holding tool) is breaking the crank pulley bolt loose. Once that is done everything else is pretty straight forward. The front cover comes off and then you can access all of the guides. At your mileage you will probably find that the tensioner is worn out and will need to be replaced. If you are on the original water pump I would suggest replacing it while everything is uncovered. Do a search on this site. There are quite a few post on the 103 engine cylinder head job with some good pics.

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Jim

Sounds good,, where can i get this tool to hold the fly wheel, and what time frame am i looking at?

Should i replace the chain while eveyrthing is apart?

Do a search on here Evan. It will be this evening before I can get the tool p/n. Phil at "partsshop" may be able to help if you give him a call.

The chain is up to you. Personally, I would change it but there are more experienced than me on here that say they have never had to change a chain on the 103 engine.

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Jim

I do not know if you have seem this post but, here we go:
http://www.peachparts.com/shopforum/showthread.php?threadid=68627&perpage=15&highlight=head%20job&pagenumber=1
I hope it helps.
Good luck!

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J.H.
'86 300E

there is just a small piece of the guide rail missing,, it does not appear to carry any kind of load,, it is the section of the rail that is going straight up to the sprocket.. would this cause a problem if i didnt replace the guide rail???

the problem is the guide is brittle enough to break. and hopefully, the broken piece is in your hand and not in the timing cover, where the chain can pick it up and force the chain off a gear. good luck, chuck.

Yes i have the piece that broke off,,, so does that mean its not vital that i replace it??

it broke because it's brittle and will break again. i wouldn't let it break again. good luck, chuck.

I ordered the parts to replace the Outer Guide Rail and Timing Chain Tensioner... Does anyone have a resource or instructions on step by step on how to replace this,.,

it sounds like you don't want to do the rails and you are looking for an approval from somebody in the forum...and I do not blame you for it. What people are telling you here is that if a piece of the rail broke off with a tap from the head, chances are, that the rest of the rail is just as brittle and may break in the future. You are already half way there so.... Bad things can happen to your engine with a broken rail but, if you take the risk and decide not to change the rails at this time may be nothing will happen but, may be...
Bottom line, this is your engine, car and money. Also take in consideration how long you are planning to keep the car, the condition of the rest of the car and if you have the extra time ( a lot, depending on you expertise), tools (not many) and manuals (highly recommended) in doing the extra work. Only you can decide...
Good luck with whatever you decide to do!

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J.H.
'86 300E

Good job explaining it JH. I just recently did a head on a customers 300SE and broke the upper part of the same guide rail when I pulled the cylinder head. I went ahead and changed out the timing chain tensioner rail and am glad I did. There is really not that much to it to go ahead and do this procedure. I have attached a couple pics from that job.

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Jim