V6 screw up

[jens_munk]

A broken cam shaft!? That sounds pretty wild and I have never heard of this on any car before. Is this a known problem on the KV6?


I used this tool to hold the cam sprocket wheels with the lock pin temporarily removed.

Originally Posted by mh007

As already said, depending on how you removed the rear sprockets, my first thought was broken camshaft.
How did you hold the camshafts still when you loosened & tightened the bolts?
Another thought is that if you had a stray spark from a coli pack etc, that would also give you a misfire of course but you may also hear a kind of 'ticking' noise.
Personally, I would remove both cam covers & physically check the camshafts & also re-align all the timing (with cam covers removed) & check the position of the cam lobes.

[SD1too]

Originally Posted by jens_munk

I did buy a set of tools, but besides the locking pin, I ended up not using it ... I did temporarily remove the lock pin loosening and tightening those two bolts.

That’s interesting.

1. When loosening the rear sprocket bolts, how did you stop the camshafts turning?
2. How did you refit the rear sprockets and new belt assembly without the special holding tool?
3. Without using special tools, how did you turn the exhaust camshaft back into position when refitting the rear belt/sprocket assembly?

Simon

[SD1too]

Originally Posted by jens_munk

A broken cam shaft!? That sounds pretty wild and I have never heard of this on any car before. Is this a known problem on the KV6?

Only when people try not to use the special tools.

I used this tool to hold the cam sprocket wheels with the lock pin temporarily removed.

Front or rear please Jens?

Simon

[jens_munk]

1: With the tool in the previous post.


2, 3: With care and then I actually used a guide pin from the tool kit to get the sprocket on the intake cams in place.

Originally Posted by SD1too

That’s interesting.

1. When loosening the rear sprocket bolts, how did you stop the camshafts turning?
2. How did you refit the rear sprockets and new belt assembly without the special holding tool?
3. Without using special tools, how did you turn the exhaust camshaft back into position when refitting the rear belt/sprocket assembly?

Simon

[jens_munk]

I used the holding tool on all of them being very careful to ensure the cams were "free" when loosening or tightening the bolts.

Originally Posted by SD1too

Only when people try not to use the special tools.

Front or rear please Jens?

Simon

[SD1too]

Originally Posted by jens_munk

2, 3: With care ...

Sorry Jens, I need a proper explanation. I have done this job and know the difficulties.
How did you keep the two sprockets and new belt as an assembly whilst refitting it over the guide pins? How did you simultaneously turn the exhaust camshaft so that its sprocket could engage with it in the correct timed position?

Simon

[SD1too]

Originally Posted by jens_munk

I used the holding tool on all of them ...

Let’s take the front sprockets. How did you hold both of them in a precise position whilst threading the new belt tightly? How did you then simultaneously refit the hydraulic tensioner and engage its pulley? Did you have people helping you?

.. being very careful to ensure the cams were "free" when loosening or tightening the bolts.

Sorry, what does “free” mean?

Simon

[kaiser]

If you have countered the torque from loosening/tightening the bolt at the end of the cam, by holding the sprocket, your cam will be fine. The only thing you don't do, is holding the camshaft, as the torque from undoing the bolt can cause it to crack or break.
If you have not done that, move on, as the crank will be fine.

[jens_munk]

Yes, I did have a helper, since you are at least one hand short doing to yourself.


The methods are described in the Haynes manual. For the rear belts, the wife holds the exhaust sprocket at the marked position (with the tool in the front end), and with the guide pin in the intake cam bolt hole, the belt and intake sprocket can be put almost in place. You then rotate the exhaust a little so the intake catch the notch and hand tighten the bolt initially.

Originally Posted by SD1too

Let’s take the front sprockets. How did you hold both of them in a precise position whilst threading the new belt tightly? How did you then simultaneously refit the hydraulic tensioner and engage its pulley? Did you have people helping you?

Sorry, what does “free” mean?

Simon

[jens_munk]

I have always held the cam sprockets with the tool when tightening or releasing the bolt. Never from either end of the cam. The only thing done through the cam is locating the intake sprocket but that torque is just normal valve spring operation.

Originally Posted by kaiser

If you have countered the torque from loosening/tightening the bolt at the end of the cam, by holding the sprocket, your cam will be fine. The only thing you don't do, is holding the camshaft, as the torque from undoing the bolt can cause it to crack or break.
If you have not done that, move on, as the crank will be fine.