No start Citroën C4 Grand Picasso HDI-110 2010-2013

[Steve Walsh]

You could be lucky and have minimal damage, I would take the top cover off and check it out before making a decision as to wether it is worth doing. I would always do it but I have the skills, time , and tools. Plenty of info on the web and forums. I had a mates in workshop a few years ago, belt had jumped, broke two rockers. New belt kit and 2 rockers later it was back on the road. Stiil going strong

[RichardW]

So the rockers are sacrificial to protect the valves, so what happens to damage the cams?

The lobes are pressed on, rather than it being a solid machined item, and they spin on the shaft.

[xantia_v6]

See viewtopic.php?p=570212#p570212 and the pages before and after....

[leithant]

Thanks. Any idea when this started being an issue on PSA engines?

[RichardW]

Not really, certainly a problem on DV6 (and presumably 4) engines, but earlier 2.0 (DW series) HDI engines didn't suffer from this AFAIK.

[shtu]

Thanks. Any idea when this started being an issue on PSA engines?

A roughly 15 year old cambelt breaking isn't really an issue with the engine or Citroen.

[RichardW]

I took the question to be more about the press on lobes rather than cam belt failure....

[leithant]

I took the question to be more about the press on lobes rather than cam belt failure....

yes, sorry I wasn't clearer. The cam lobes.

[shtu]

Ah right, gotcha.

Not really an issue as such, it actually saves the engine from worse damage, as the lobes spin rather than driving the valves hard into the piston and bending them. I've not heard of the cam lobes moving without a belt breakage to force the matter.

It's counterintuitive - most folk (me included) expect a camshaft to be machined from a solid blank. It'll have been done to save half a penny on manufacturing costs.