Engine 'tink' when warming up?

[Andy Esprit SE]

Hi,

Please can you have a look at the following video and let me know if the electrical sounding tink is normal?

http://m.youtube.com/watch?feature=plcp&v=yppUQij3PVI

This example video was on a cold morning just started up, I'm hoping its just the exhaust manifold expanding at it gets warm? It doesn't do it at all once up to temperature, does anyone else's do this?

[Andy Esprit SE]

Hi Scott, I filmed it on my iPhone and uploaded it straight on to you tube, hopefully it plays ok via the link its the first thing I've uploaded on to you tube so learning as I go along. It's a loudish electrical sounding crack really, only does it 4 or 5 times on the video, I've had a root round underneath and couldn't find anything loose as of yet, it's had a new timing belt recently but did it before then too ?

[Vulcan Grey]

does sound like an electrical spark.  Can you film again in the dark?

[Andy Esprit SE]

Good idea! I'll give it a go in the dark this weekend and hopefully we'll see a flash

[Sparky]

Can't access the vid for some reason, but I believe I know what you're hearing.  I've heard it many times on Esprit engines as they warm up after being damp. I believe It's rapid heating of the manifold which flashes water droplets to vapour, and it sounds just like electrical discharge.

[Whirlybird]

Can't hear anything on your video clip (no sound) but mine does the same thing if it's been left for a couple of weeks or starting after a very cold spell.

[910Esprit]

I've not listened to the clip, but check the earth lead is present on your tensioner bearing 

[Vulcan Grey]

Earth lead on tensioner bearing??? No such thing on an SE.

[910Esprit]

Oh well fancy that?  The earlier models have one as the bearing is insulated from the tensioner housing, thus causing static build up and discharge.

[Wilf]

My earth strap for the tensioner fell apart and when I asked sjs they said it was more for radio suppression.

[910Esprit]

I suppose it depends who you listen to, but according to my source, the static discharge prematurely destroyed the tensioner bearing

[Andy Esprit SE]

Thanks for all your comments, I only fire it up once a fortnight so hopefully the damp idea is all it is? I'll still check for sparks in the dark just in case, the garage has a problem roof so it's under cover in there but it does get damp ( it's a job for next summer to be fixed)

[Vulcan Grey]

Steve,

 

The later 910's don't have an auto tensioner.  They have a solid metal hub pressed into a dual race sealed ball bearing where the outer race is the belt pulley.  They have an offset bolt hole which makes the hub eccentric.  You manually turn the tensioner against the belt and lock it down with the bolt.