On the problem of the timing chain

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Re: On the problem of the timing chain

Postby pantiancai » Sat May 05, 2018 4:34 pm

Technician wrote:CGMA?

I read something about management and training regarding the above, but I'm sure it might mean something different!

Then there is a difference of the OTTO cycle that I'm not aware of, that being crank rotation being in opposite direction to cam rotation!

That's got to be a misunderstanding surely!

I am a newcomer and I do not understand the truth, but I want to understand it. I am not sure if you have a better opinion to help me. Thank you.
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Re: On the problem of the timing chain

Postby Technician » Sat May 05, 2018 6:50 pm

pantiancai wrote:
Technician wrote:CGMA?

I read something about management and training regarding the above, but I'm sure it might mean something different!

Then there is a difference of the OTTO cycle that I'm not aware of, that being crank rotation being in opposite direction to cam rotation!

That's got to be a misunderstanding surely!

I am a newcomer and I do not understand the truth, but I want to understand it. I am not sure if you have a better opinion to help me. Thank you.


Sorry if it came across wrong, I was basically saying that I did not know what you meant by CGMA and what I read online was probably incorrect to your abbreviation.

Whichever way the manufacturer chooses to design the engine to rotate does not matter, it can be either clockwise or anti-clockwise, however, most engines if not all I've ever worked on do rotate 'clockwise'. This means that unless an idler gear or pulley arrangement has been included, then the camshaft and crankshaft will both turn in the same direction, i.e. normally clockwise.

If you could take a photo shot of the engine drive assembly and let us have a first hand look at the arrangement then I'm sure we will be able to advise you accordingly.

Sorry for any misunderstanding.
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Re: On the problem of the timing chain

Postby pantiancai » Sun May 06, 2018 5:12 pm

I am a novice and don't know much about it. Do you have a better explanation to help me? Thank you
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Re: On the problem of the timing chain

Postby Technician » Mon May 07, 2018 9:15 pm

What I think you are concerned about is 0.7 degrees difference between new chain(s) fitted against the old chain(s) fitted prior to work being commenced, what I'm not sure about is whether you changed one chain or two!

A professional would more than likely change all the parts as a kit, so two chains and gears including the tensioning device. I never come across a duplex chain setup causing problems, which is not to say it is not impossible.

Does the engine run normally and if it does what exactly is the problem?
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Re: On the problem of the timing chain

Postby ashtray1987 » Tue May 22, 2018 3:34 am

Hi Guys,

Do bear in mind that unless the camshaft adjusters are disconnected, the engine control unit will try to correct for any timing chain stretch by adjusting the PWM signal to the camshaft solenoids.

This is the case with Mercedes-Benz, when the timing chain stretches, or the balance shaft sprocket is worn, when the camshaft is out by 6 degrees crankshaft angle, a fault code is set stating "continuous camshaft adjustment".

Once the electrical connection at the camshaft solenoids is disconnected, the hydraulic adjusters will retard to their base setting, allowing you to see the true cam/crank correlation.

Hope this helps.

Kind Regards
Ashley
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