I'm looking for a good web site for a DIY job for a head gasket replacement on a M103 (1990 300E). I certainly appreciate your input. Thanks!

Try this download

Ian B Walker Pdf - Download Owners Manual PDF

Or

startekinfo.com

shop resources

Manual is in there.

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Jim

If its a straight gasket swap, this should help you:
http://w124-zone.com/articles.php?article_id=36

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2016 Monsoon Gray Audi Allroad - 21k
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2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

GOLDEN!! Thanks all for the input...will be in up to my elbows in about 30 min. Then I have another head gasket to replace on a 300SEL with the same engine. I should be well versed in the art before I get done.

It is straight forward, just take your time with it. You will want to get someone to help with lifting head in/out.

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Jim

I got stuck with the threaded pin on one of the timing chain guides. I have a sliding hammer, but nothing that small to pull that pin...any suggestions? Do I need to buy the special tool to pull that? (And everything else was going so well!!)

As Jim said, it is a straight forward job. There are, however, a few things to be aware of if you have not done one, or one like it before:

The chain tensioner is a ratcheting tensioner. You will have to reset it when you go back together. With the tensioner removed, push the plunger all the way through toward the engine and out, then START it back through before putting the tensioner in place. When you start the engine oil pressure will adjust it in position.

If you take out the camshaft, when you put it back in place get all your rocker arm assembly bolts started, but tighten them all a little bit at a time. If you tighten one pair of cam journal bolts all the way, you can break the camshaft. A little at a time all across, then a little more....

Make sure you measure the headbolt length and compare to the maximum length specified in the manual. If they are too long, get new ones.

When you torque the headbolts you will feel like you're going to twist them in half. Either mark each one after the initial torquing so that you know which ones you've turned 90 degrees or work the pattern for the 90 degree angle torque WITHOUT STOPPING. This is so that you don't get out of order or add 90 degrees to one that has already had 90.

For the M103 I find it easier to leave the intake manifold in place. On the M104 I think it's easier to leave it on the head and remove the whole thing. On the 103 you can get to some of the manifold bolts from underneath with a very long extension.

Be careful when installing the top timing cover. Use your fingernail to make sure the shaft seal does not fold as it goes over the end of the cam while you slide the cover STRAIGHT rearward. Use a slippery sealant on the U gasket below that cover.

Hope this helps.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

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I have a fancy and expen$ive puller for those, but it's really unnecessary. With a long bolt that will screw in the pin and a series of nuts and washers, you can fashion a way to get them out easily.

Hope this helps.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

I never did understand how a puller could pull that pin without breaking the guide. Does it go around it?

Please excuse my ignorance, but its been 5 years since I did the m103 head, and I remember having the same issue.

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Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2

If you go to my link it shows you guide pin removal. I hope you are leaving the intake manifold in engine....

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

Try to get your hands on a long "Wobble head" extension. A universal joint will not do you much good as it is a very tight clearance. When I did this job I found it invaluable for getting some of the intake bolts off.

I totally agree. It is a little controversial, but I believe that leaving the intake in place in the M103 is the only way to go.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

As long as you release the timing chain tension before pulling the pins, it won't break the guide.

Good luck with it.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

[IMG][/IMG]

this is how I removed the pin....