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  #1  
Old 06-21-2007, 04:31 PM
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Question What Exactly does Adjusting the Valves Do?

What does adjusting the valves actually do? i.e., better milage? run smoother? quieter? etc?

I am not too mechanically inclined, but I do love to play with diesel engines. In this case, I will take the car to a mechanic, but what if he does it incorrectly? Will it destroy the engine? What damage can be done to the engine if it is done wrong?

Thank you.

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  #2  
Old 06-21-2007, 04:37 PM
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Worst possible case scenario is that you completely undo the lock and reg nut on the valve and the valve drops into the engine. Chances of this happening are small if you are aware it can happen.

Basically if the valves are to tight they can actually stay open and never fully close. A proper gap also allows for better oiling of the cam lobes.
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  #3  
Old 06-21-2007, 05:26 PM
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A mis-adjusted valve will be prevented from closing or opening fully, resulting in the loss of compression and/or inadequate breathing of the affected cylinder. Symptoms are typically excessive smoking and difficult starting. The job of adjusting the valves is pretty straightforward if you have the right tools (like the special bent wrenches) and a good manual (like the Haynes W123 manual). If you're gonna pay someone to do it, make sure it's someone who's familiar with these diesels and has done the job before.
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Old 06-21-2007, 07:40 PM
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Do not have your valves adjusted on your diesel by a shop that is not BOSCH Certified. Also don't let them charge you more than $120.
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  #5  
Old 06-21-2007, 09:12 PM
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Quote:
Originally Posted by FlossHogg View Post
Do not have your valves adjusted on your diesel by a shop that is not BOSCH Certified. Also don't let them charge you more than $120.
BOSCH had nothing to do with the valve system...why would a shop need to be certified by them to work on it?

If the valves are too tight (which is how they tend to get over time) they can hang open and be burnt (eroded) by combustion gasses. If they are too loose you will not get ideal mileage, and will have some valve noise.

It does take some practice, but is not rocket science. Buy your self a feeler gauge, manual, and if you want the fancy bent wrenches (I have never needed them, but it would make the job easier) and dive in!
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  #6  
Old 06-21-2007, 10:09 PM
ForcedInduction
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It's basically caused by the hammering of the valve and valve seat as they open and close many times per second. Over time, this hammering wears them down and reduces the gap between the valve stem and the tappet. It's not much wear (Hundredths of a millimeter change) but it does make a difference.

If you are doing a valve adjustment yourself for the first time, remember to make sure if you are adjusting an intake or exhaust valve and double/triple check your adjustments before you put the valve cover back on.
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  #7  
Old 06-22-2007, 01:14 AM
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im not sure if i would suggest taking off the cam to do this procidure. (takes a second and thinks about what he just said) lol... carefull not to bust your knuckles.
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Old 06-22-2007, 01:41 AM
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w124 300td iddle low

Hi does anyone here know how to get my otherwise very powerful wagon to iddle stronger? already tried the knob at 7.
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  #9  
Old 06-22-2007, 01:58 AM
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Hi does anyone here know how to get my otherwise very powerful wagon to iddle stronger? already tried the knob at 7.
It would be better to start a new thread to ask such an off-topic question rather than taking over this one.
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  #10  
Old 06-22-2007, 06:10 AM
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Exclamation That's why we have Public Libraries !

If you would take the time and go to your library......look for a book that explains how internal combustion engines work.....and read up on the how and why of any 4 stroke internal combustion engine.

One must walk before one can run.......

SB
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  #11  
Old 06-23-2007, 12:36 AM
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Quote:
Originally Posted by Shorebilly View Post
If you would take the time and go to your library......look for a book that explains how internal combustion engines work.....and read up on the how and why of any 4 stroke internal combustion engine.

One must walk before one can run.......

SB

Now, now Brother Billy.

Remember how that one kind old gentleman encouraged us to find a way back when we were young whippersnapers just getting our hands dirty? Well, we've gotta be charitable and encourage them and pass it on. My boy laughs at me and my advice but I notice that in practice, he falls not too far from the tree...I've even learned a few things from him.

Anyway! Enough of the touchy, feeely stuff..

Damn boy, like Shorebilly said ...go search the threads and check out the library, use yore head son! THIMK!

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  #12  
Old 06-23-2007, 10:46 AM
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Quote:
Originally Posted by Gray 1985 300D View Post

I am not too mechanically inclined, but I do love to play with diesel engines. In this case, I will take the car to a mechanic, but what if he does it incorrectly? Thank you.
If you like too play with diesels, adjusting your own valves is an ideal place to put some time and energy. Owning one of these cars isn't such a good deal if you have to pay someone else too do every little thing. Might as well just drive a Camray or Subaru as its a whole easier too find someone competent to work on them.

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