The occasional bottom end hollow clunk.

[srgtlord]

So I never really thought about this until now but, just figured it was just one of those vw noises , but what would cause an occasional bottom end knock on a NA 1.6 that would last anywhere from 15 seconds to 1 minute? Just wondering if there is something else I should look at with the engine out.

[ORCoaster]

OIL Pump?

[RabbitJockey]

When do u hear it?  And what makes u think its bottom end?  Is it just after a cold start?

[srgtlord]

It used to be only after a cold start . It sounded like someone was hitting the oil pan with a hammer.

[theman53]

Tell that someone to knock it off...Or take the hammer away.

[ORCoaster]

Make me chuckle,..   Something then, he meant something not someone.  Or is it the comparative method of association in which he speaks. 

Trolls perhaps?  Don't they live under things?

[RabbitJockey]

It's probably just normal diesel clatter or ur timing is too advanced when a friend of mine first got his diesel rabbit together he thought the pistons were slamming into the head or something,  this was in the summer, I told him loosen the pump and rotate it away from head a bit and all was well

[srgtlord]

Damn gremlins

[RabbitJockey]

Damn gremlins

I named all mine Ronnie, Bobby, Ricky, and Mike.

[theman53]

I would think it would be fuel related. Maybe injector related. Even my TDI will make some bad noise whenever it is cold and cold starting. I think what trev said is accurate as well.

If there is a hammer down there you should take it away, the pans dent eventually.

[srgtlord]

But the strange thing is the issue would come back after fully warmed up at idle after it reached operating temps.

[TylerDurden]

How old are the IM shaft bearings?

[srgtlord]

Lets put it this way, I plan on replacing them. Im just not sure if this will solve this odd issue.

[ORCoaster]

Damn gremlins

? Isn't this the season to be hanging and ringing bells?

Put a bell on it.  Then you won't hear the hammer like noise

[pointynoggin]

I got a cherokee that did something like that, 5sec of hammering on start up.  Turned out to be the harmonic balancer.