Something in the engine

[Andy1972]

Hi I think a small nut or something 4mm5mm dropped into air intake on our izusu engine couldn't find so thought it was ok put the air filter back on after cleaning it started engine to charge batteries slight tapping noise I know izusu 42 is pretty bomb proof but if it has gone in do I need to worry

[Midnight]

7 minutes ago, Andy1972 said:

Hi I think a small nut or something 4mm5mm dropped into air intake on our izusu engine couldn't find so thought it was ok put the air filter back on after cleaning it started engine to charge batteries slight tapping noise I know izusu 42 is pretty bomb proof but if it has gone in do I need to worry

 

You "think" or you know for sure? If sure I suggest you worry or take the head off and fish it out before it completely knackers the piston

[Graham Davis]

Duplication reported.

[matty40s]

Two somethings...

[MtB]

9 hours ago, Midnight said:

 

You "think" or you know for sure? If sure I suggest you worry or take the head off and fish it out before it completely knackers the piston

 

That will have happened the very first full revolution of the engine on starting it.

 

Whatever it was will have been embedded in the top of the piston immediately. If the engine still runs ok it will probably stay there for the rest of its life -  but there will always be a risk it comes out and bends a valve or does something terminal at any point in the future. No doubt just as you're passing an unprotected weir on the Trent or something critical. 

[Bee]

As MtB says, it will be embedded in the aluminium piston.  Personally I would take the head off sooner rather than later. I find engines can cope with hazel nuts and peanuts but anything bigger than cashews is trouble. Coconuts are terminal.

[MtB]

2 hours ago, Bee said:

I find engines can cope with hazel nuts and peanuts but anything bigger than cashews is trouble.

 

You've fed all of these into into your engine's air intake to find out what happens?

 

You're NUTS! 

 

 

Edited December 1, 2021 by MtB

[john.k]

Taking the head off just costs a gasket and a bit of time.......Ive found where things like nuts and screws go into a cylinder,they move about pockmarking both piston top and the head surface......it may even cause the piston to crack if the hit is at the edge .

[David Mack]

1 minute ago, john.k said:

Ive found where things like nuts and screws go into a cylinder,they move about pockmarking both piston top and the head surface.....

You make it sound as if you regularly drop things into engine air intakes!

[MtB]

12 hours ago, Andy1972 said:

Hi I think a small nut or something 4mm5mm dropped into air intake

 

More seriously, can you clarify please if you mean a machine nut made of metal e.g. steel, or an organic nut like a peanut?

[David Mack]

Would something 4-5mm in size get past the inlet valve and into the cylinder? 

[john.k]

You often see one piston and head marked where something has been there,and either gone out the exhaust,or manually removed ..........one of the more common things is a broken ring that works its way up into the top in pieces.

[manxmike]

I once dropped a small piece of a wooden pencil into the air inlet of one carb on a Triumph Bonneville. When I say small, it was about 2mm and WOOD. It completely knackered the piston and the valves. I would seriously suggest you lift the head and extricate the offending item, carefully inspecting the piston crown, valves etc etc.

[Tracy D'arth]

You now realise the folly of dropping your nuts into an engine. And the even bigger mistake of starting it up!

 

There is a distinct risk that this nut will be imprisoned at the edge of the piston and the deformation of the aluminium will trap the top ring causing a bore score. If it jumps about and wedges a valve open, the piston will hit the valve head and do considerable damage, busted piston, bent con rod, and/or smashed rocker. Heaven forbid if it breaks the head off the valve.

You will not have peace of mind till you take the head off.

[MtB]

13 hours ago, Andy1972 said:

started engine to charge batteries slight tapping noise

 

A regular tapping noise or a generally random clatter? 

 

If absolutely regular I'd say it is embedded in the piston now, and hitting the top of the combustion chamber on every piston stroke. If a random clatter it's probably chattering about behind an inlet valve and will do some serious damage if it manages to jam the valve open.

 

[Slim]

14 hours ago, Midnight said:

 

You "think" or you know for sure? If sure I suggest you worry or take the head off and fish it out before it completely knackers the piston

I would think "thinking" is worse than knowing..

[john.k]

If you want a horror story......motor has a miss and a rattle, I say a head dropped off an inlet valve ,and apparently neatly wedged in the combustion bowl of a piston.......rocker cover off,and one valve has no clearance,more indication of a broken valve.....tow back to the yard,and Im ready to take off the head......boss comes out,along with assorted crawlers,starts motor......"ooo..ooi john lad ,oi dont think it be valve,it will likely clear itself "  one of   the crawlers revs the motor ,there is a massive crash ,and lots of noise and smoke.........boss is ."..oo..ooi ,better have the head off then".......head off,valve is smashed through the  head ,piston broken ,rod bent like a pretzel, a maincap broken ,and bent crank.

[magnetman]

I remember this coming up before with Isuzu engines. 

 

Some sort of poor design which allows a nut to be ingested. 

 

I think it was a nut holding the air cleaner box on which vibrated loose. 

 

It was years ago, a thread on here

[magnetman]

This thread 

 

 

 

 

[Peter Thornton]

On 01/12/2021 at 10:12, manxmike said:

I once dropped a small piece of a wooden pencil into the air inlet of one carb on a Triumph Bonneville. When I say small, it was about 2mm and WOOD. It completely knackered the piston and the valves. I would seriously suggest you lift the head and extricate the offending item, carefully inspecting the piston crown, valves etc etc.

I’m guessing you were balancing the carbs?

[manxmike]

Yes I was, a fairly simple job usually, set the revs on one carb, match on the other, then run with both and fine tune. I never bothered with vacuum units - too much like hard work. I'm still not sure how I got a piece of pencil in there though ..............

[Peter Thornton]

After which you'd try to adjust the two sets of points...........

[cuthound]

It may prove cheaper and quicker for the OP (or his mechanic) to use an endoscope to look into the combustion chambers by removing the injector or glow plugs, rather than removing the head.

 

However if the nut is seen, then it will be necessary to remove it and repair any damage.

[manxmike]

On 02/12/2021 at 14:03, Peter Thornton said:

After which you'd try to adjust the two sets of points...........

Ha, I'd gone electronic ignition by then - soooo much easier and far more reliable, Boyer Bransden I seem to remember

 

Edited December 5, 2021 by manxmike