420SEL won't start... cracked valve cover..
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Joined: Jun 2009
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420SEL
420SEL won't start... cracked valve cover..
To start things off, I don't know a whole lot about cars but I'm good with my hands. I've searched and haven't found any good answers to my question.. Here's the story. So I go to start my car and it starts up fine and runs for about 2 seconds and I hear a snapping sound.. I figured it was the timing chain but it wasn't.. The valve cover is cracked but the chain looks fine and it's clean and tight - even when I try to start it. It has spark and the vacuum seems good. What should I check next??
Super Member
Joined: Aug 2005
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From: Mercerville New Jersey
1991 560SEC Teal 1989 420SEL Ice Blue 1984 500SEC White
Tensioner, rails, guides, sprockets you can name it.
Something did happen to the chain to allow it to crack the valve cover.
Have you tried cranking it over by hand?
Does it start and run?
Most likely not.
Something did happen to the chain to allow it to crack the valve cover.
Have you tried cranking it over by hand?
Does it start and run?
Most likely not.
Thread Starter
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420SEL
Thank you.
Super Member
Joined: Aug 2005
Posts: 801
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From: Mercerville New Jersey
1991 560SEC Teal 1989 420SEL Ice Blue 1984 500SEC White
It must have jumped timing. Do not run it any longer.
It will need the chain rails and guides as well as the tensioner replaced.
Hopefully no head damage since it seems like it has jumped timing from one of the 2 cam sprockets.
It will need the chain rails and guides as well as the tensioner replaced.
Hopefully no head damage since it seems like it has jumped timing from one of the 2 cam sprockets.
MBWorld Fanatic!
Joined: Apr 2006
Posts: 1,332
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From: Toronto
2006 E320 CDi, 2008 3/4 Ton Suburban, 2007 "rice rickshaw" Accord 5 speed
I replaced my w126 timing chain at 100,000 miles and had done some research on this. The job is expensive. MB charged me about CD$3,000.00 at the time. New chain, new sprockets and "fingers" or followers, labor included.
If nothing is damaged and you intend to keep the car then you should do the repairs.
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420SEL
Hey guys! I'm really sorry I haven't come back for an update, I've been very busy. Well, I'm tempted to do the job myself but I'm kind of afraid that I'll get half-way though and get stuck on something or mess something up. I've called around and everyone has told me it's going to be about $3,000 to fix. Can I check for valve damage myself? If so, what tools would I need? I really want to keep the car but I definitely can't pay $3k to fix it.
