Cambelt tensioner failing?

[copestake]

Hi all,

Here is a video of turning the engine forwards and backwards. Does this look like the tensioner has failed?

https://www.youtube.com/watch?v=0RNDWbXhMCc

Cheers

Edited by copestake on Wednesday 9th September 16:28

[crossy67]

Where's the video?

[copestake]

D'oh, added now.

[crossy67]

Looks knackered to me

[copestake]

Thanks, could have been messy!

[crossy67]

Lucky man!

Had a similar thing on an old Volvo V70 diesel a few months back. Pirelli belt kit fitted previously, replaced it with Gates, cost twice as much but I have never seen a Gates kit cause problems if fitted correctly.

[Spangles]

It's a sprung tensioner, it's supposed to do that.

[crossy67]

Not that freely surely.

[andyiley]

So, let me get this straight, you are alternately turning it the right way & then wrong way?

If so, then the tensioner appears to be doing its job correctly in that video.

[Spangles]

crossy67 said:

Not that freely surely.

That's the range of its movement, we don't how much force is being applied to the belt. However I've never known the spring to fail, only the pulley.

[copestake]

To provide a bit of back story, at around 1500rpm on load you can hear the valves hitting the pistons so seems it's slipped?

Whoever changed the belt last has broke the camshaft so it's not possible to use the locking plate. Great. But reading this there's a special way to set the tensioner, wouldn't surprise me if it hasn't been done like this.

http://ww2.gates.com/europe/file_display_common.cf...

[bearman68]

Doesn't necessarily look failed to me (personal opinion). However if it's at all doubtful, it's worth changing. Had a look at the gates guide you posted, and that would seem a possible cause.
However, I repeat my comment -if in doubt, change.

Best of luck.

[guards red]

You appear to be spinning the engine in the wrong direction in which case the tensioner will slacken as it's not designed to tension the belt in that direction. (apologies if my sight has deceived me)

Spin the engine clockwise a full revolution with the plugs out. It should spin freely and smoothly but as a previous poster has said that tensioner rollers usually fail at the bearing.

If the roller is solid and not rocking on it's bracket and you still suspect the tensioner than I would check that it is fitted correctly.

Finally, are both cams actually spinning?

[copestake]

The last documented change of belt was 2008 decided to order a new kit as advised but just had a look at the tensioner and everything seems to be OK though I did notice this..



You can see the mark where the bolt has been and according to the PDF guide it's not correct. I can't think of any other cause? Cams are OK, VCT seems OK. I should have checked myself to see if the timing was out but didn't think at the time.

[copestake]

Engine now knocking (big end knock). Low compression, looks like valves in cylinder 4 bent. Looks like the engine is coming out.