Ticking valves, but not always, 2000TC

[Wilfred Oldtimer]

Good evening,

Most of the time my engine runs very nice and smooth, however sometimes I can hear one or more valves ticking varying in sound level.
Immediately after purchasing the car I changed the oil to clean the engine and drove some long distances to let it getting hot and happy.
This made a lot of difference in how the engine is performing now, but occasionally I hear a ticking valve.
For example, this evening I took it out of the garage, drove a little, turned off the engine off and voila and there was the valve again, to disappear after five minutes of idling.

I'm not sure how much tension I'm suppose to sense on the upper timing chain, my idea is that this one is too low, so my question is how to increase the tension and does this affect the timing on the camshaft ?
Since the ticking is not always there, the timing chain tension could be the reason for this ?

Btw, compression test showed about 12.5 bar for each cylinder, with minor difference between them

Cheers,
Wilfred

 

[harveyp6]

Tensioners are hydraulic so set the tension automatically, but early ones had a plug that can fall out and so the oil pressure is lost, but I doubt that will cause the ticking, but it's worth checking.

 

[Wilfred Oldtimer]

Yes I know they are hydraulic, but I wondered if there was also some kind of pre adjustment.
The strange thing is that it’s not always ticking, on idle it sometimes comes and goes.

About the tensioners, could they be blocked or polluted due to old oil?
That might perhaps explain something.
The oil was definitely dead and very black.

Thanks
Wilfred