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K7M engine (Renault Sandero)

During a timing-belt and tensioner change, I used a locking-pin(an 8mm bolt) to hold the engine while breaking loose the crank-pulley bolt.

Not being an experienced mech', I'm concerned I may have inserted the locking pin at the wrong phase in the 4-stroke cycle(*), and was wondering whether that might have damaged any of the internal moving engine parts e.g. piston, valve, cylinder.

I had to apply quite a bit of force to get it loose and at some point I noticed the bolt I used as a locking pin was slightly bent.

  • I noticed the pin would go in to varying degrees/at varying lengths depending on the current phase. I since found what I think is the best position in the cycle to insert the locking-pin i.e. just before TDC on cam-gear.
Pᴀᴜʟsᴛᴇʀ2
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Jim
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1 Answers1

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Basically, no. With the pin in place, the pistons are going to be in the exact same place no matter what. It is the cam which makes the difference which stroke any given cylinder is at.

To hopefully better explain, when the piston is at top dead center (TDC), it can be at TDC on either the compression or exhaust stroke: the piston doesn't care. When it's at bottom dead center (BDC), it can be at the end of the intake or the power stroke. It doesn't matter. And the pin will still pin the crankshaft because there's only one place where the pin lines up.

Since the cam spins at 1/2 the speed of the crankshaft, it's position is what matters. If, once you've put cam belt back on, as long as the alignment marks are in the right spots, everything should be good to go. In your case, 12 o'clock position for the cam and 6 o'clock for the crankshaft.

Pᴀᴜʟsᴛᴇʀ2
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