Hi all.

I have a 90 300E that I just bought and it needed a head gasket. I had to send the head out for machine work, and when it came back the cam was back at TDC and my alignment marks gone.

I zip tied the cam gear/sprocket to the chain when I removed the head, the crankshaft has not moved.

Can I just rotate the cam so the dowel pin lines up on the sprocket (arrow)? Or must I put the engine at TDC now as well? Dumb question maybe, I just dont want to screw anything up.

If you pm me your email i can send you a PDF with all the info you need.

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600SEL '91
300E 4Matic '88
240D '83
280SE '77
350SE '73
The most complex systems can fail in the simplest way.
Contra verbosus noli contendere verbis, sermo datur cunctis, animi sapientia paucis.

i don't believe in the lord! He's never bought me a Mercedes Benz.

You've got mail.

__________________
600SEL '91
300E 4Matic '88
240D '83
280SE '77
350SE '73
The most complex systems can fail in the simplest way.
Contra verbosus noli contendere verbis, sermo datur cunctis, animi sapientia paucis.

i don't believe in the lord! He's never bought me a Mercedes Benz.

Thanks for that.

Do I have to wait to turn engine by hand until the both the head and chain tensioner are re-installed? Again maybe another dumb question lol.

No you don't

__________________
600SEL '91
300E 4Matic '88
240D '83
280SE '77
350SE '73
The most complex systems can fail in the simplest way.
Contra verbosus noli contendere verbis, sermo datur cunctis, animi sapientia paucis.

i don't believe in the lord! He's never bought me a Mercedes Benz.

Thanks daddi!

Got the engine over to TDC, lined up the cam to TDC, and the cam gear slipped right back on.

One step closer.....

Make sure you torque the head bolts correctly -- very important. Along with the chain tensioner removal and installation in the correct order, again very important and cannot be skipped.
Also take the opportunity to inspect the chain guides.

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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

Yes. I did see the extra caution about the chain tensioner. I pushed it all the way through then re-inserted it from front about 2 clicks by hand when reinstalling.

Torquing those head bolts is a serious workout. I saw two different torque values 55nm and 70m. The Elring gasket I bought said 70nm + two 90 deg turns, so that's what I went with. I bought a cheap torque angle gauge that was nearly worthless, I thought it would be spring loaded or something. So I just eyeballed the 90deg turns to the best of my ability.

Got her fired up this morning, let it idle for 20 minutes without coolant cap to let the gasket swell. All appears good!

Wouldn't start at first; I forgot to reconnect a hose to the idle control valve. . Had a lifter tick for the first few minutes of running that eventually resolved itself. Overall runs much quieter than before the job.

I am still amazed at the cylinder wall crosshatching at 225K. It looked like new still!

Here's to another 225K of motoring.