General loose bolt/terrible rattling noise in engine

[dcj]

Hi there - hope someone can shed some light on my problem.

I was motoring along the highway in my Ducato 2005, 2.8 turbo charged deisel, when I noticed what sounded like a rattling/vibrating noise coming from the driver's side of the engine (RHD). It steadily got worse and worse, and I ended up limping into a country service station and getting a tow to my destination.
The engine still runs fine - no loss of power, no oil or water leaks, and I can still drive it OK, except for this terrible noise.

The only thing I can find that's out of place is the threaded end of a bolt sticking out of the end of the motor, about 1/2 way down. I can pull the bolt out to about 6cm, and also push it in so only 1 cm is protruding. The bolt's about 10mm dia, and I'm sure it's at least partly responsible for the rattling noise.

Does anyone know what's supposed to be attached to this bolt? It's just sitting there loose, with no nut on it - as if whatever was on it, fell off as I was driving. The fact that I can pull it out a long way seems to indicate that something inside the engine was attached to it, and fell off or broke, allowing the bolt to come out 6cm or more.

I've attached a picture of the bolt, taken from under the vehicle looking straight up.
thanks,
David
Sydney, Australia

 

[Techno100]

Looks to me like it secures the plastic shield in place, can just see wear marks in the plastic where the drive belt travels.
I'd be looking at resecuring it with nut & washer and see the difference?

 

[dcj]

Thanks Techno - I did think of doing that, except the bolt can be pulled out 6cm or so, exposing a large unthreaded section - this implies to me that something was on the bolt inside the cover, and it's now not there (maybe a pulley?)

 

[K333fer]

It does hold the cover but also its the stud for the cambelt tensioner from memory

 

[Techno100]

I would say some dismantling is required to get to the route of the problem, clearly whatever the is the issue is behind that shield. Good luck and please do show us when you sort it

 

[ecunotemu]

DON'T start the engine again until you've got that cover off and fixed if the timing goes you're facing a huge bill.

 

[rayc]

Can you identify it from this photo?
http://www.motorsbros.com/images/Fiat-Ducato-28-JTD-03.jpg

 

[dcj]

Thanks for the photo RAYC - I reckon it's the bolt on your photo down in the left hand bottom area - I can see the nut about 1/3 of way across, and 1/4 of the way up the photo. It's holding a small pulley in place.

Do you happen to know what that pulley does? Is it a belt tension pulley?

 

[K333fer]

Yes that is the cambelt tensioning pulley

 

[Techno100]

I think it unlikely that the tensioner pulley itself has come loose but rather what is attached to the face of it. As said above best not risk it until you know.

 

[ecunotemu]

I think it unlikely that the tensioner pulley itself has come loose but rather what is attached to the face of it. As said above best not risk it until you know.

It looks to me like the double ended stud that the tensioner pivots on if he can pull it in and out as far as he says then its either snapped off flush with the block or stripped its own thread or the threads in the block :yuck:

 

[dcj]

Thanks to all for your valuable input. I'll get the van towed to service centre in the next couple of weeks (the van's in northern NSW, and I'm in Sydney at the moment) and get it fixed, and then I'll let you all know the outcome.
Cheers, David