Hi all,

My '93 190 2.3 is at a local shop, getting it's head gasket replaced after finding oil in the coolant.

I've used the mechanic before, and he's competent, but not a Mercedes mechanic per se.

After buttoning things up, mechanic ran and test drove - and the CAM BROKE!

He replaced it, and the replacement CAM BROKE!

What would cause this? I looked at the head and Cams with him, and nothing looks awry ( of course, I am NOT a mechanic ) but he's a bit stumped.

Any help much appreciated, as at this point I'm soliciting expert advice from people experienced w/ Mercedes in particuler.

Thanks in advance,
Mark
markl@aracnet.com

Ask if he had to shave the head....

sounds like the timing chain may be too tight. maybe hr forgot to reset the chain tensioner.
paul

__________________
Paul Roberts
Mercedes Centrum Inc.
Bellevue,WA.

I would guess the cam timing is way off (two teeth or more).

however, if the head was warped and it was machined to flatten it, the cam is now running crooked and the head is toast unless it can be align bored straight through the cam bearings. The cam will NOT flex as it turns.

If the head exceeds the warp limit, it must be bent back into shape, it cannot be machined flat unless the cam bearings are also bored and a cam with oversize bearings fitted. Failing that, replace the head.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

If the head was resurfaced because it was warped, chances are the cam bearigs are now way out of line. Top of head where cam bearings mount still has the identical 'warp' that was removed by resurfacing the head--causing the cam to bendwhen rotating and possible seize in the bearings.

Continual bending will cause it to break.

Paul was correct!!

ON the M102 engine & most other MB's the timing chain tensioner MUST be dis-assembled & reset before re-installing back into the engine. IF not there is too much tension & the cam will break as it is hollow! Have seen that problem at least 4-5 times when the "mechanic" doesn't have MB engine knowledge!

IT was his fault for not reading correct info on removing & installing the tensioner!

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