knocking sound from the snorkel

[janderson]

Is it normal to hear a knocking sound from the snorkel? 2001 Gu TD4.2T.

[Ben-e-boy]

nope but you are going to have to give a bit more info

[AB]

Airbox all secure, snorkel all secure?

Could be a lot of things rattling inside the engine coming up through the snorkel too but my money would be airbox or loose snorkel mate.

[taslucas]

Maybe a stick in there!?

Tap, crackle, pop

[happygu]

Nope, definitely not normal....

Is it a sharp metallic sound or a dull thud?

[nissannewby]

Have you had the head off recently? Or any part of the intake removed/ disassembled?

[janderson]

Thanks for replies. Nothing has been disassembled. Dull thud, thud much like the exhaust. Sounds like normal engine noise being fed back thru the snorkel. But being my first Diesel I just don’t know if it’s normal. 18 months ago the car yard that I got it from did change the head gasket thou

It’s not the stick, I pulled it out.

[happygu]

Sounds like it is the normal induction noise from the motor....

[threedogs]

Obviosly you've had a look and pushed and pulled a few things, Harmonics are a bugger in 4x4s
make sure all is tight asap , you do get slight engine noise after fitting snorkel, but not like you have described
Lift the bonnet get out the socket set and go for it

[nissannewby]

So how long ago was the head gasket changed? Do you notice any coolant loss?

[janderson]

So how long ago was the head gasket changed? Do you notice any coolant loss?

Head gasket don 18 months ago. No coolant loss

[Robo]

Not something between snorkel and car body is there?.
Have you compared your vehicle to another for comparison ?.
Snorkel is securely mounted ?.
Inner plastic mud guard loose flapping and echoing through panel to snorkel ?.
I'd hazard a guess,
a piece of the induction piping is flexing at low revs and causing a drumming sound to echo up the snorkel.
even a flex pipe with a layered construction a piece peeling back and flapping about.
some possibilities that come to mind.

(what you describe, my work truck mitsu 7 tonner has had a drumming sound from day 1).

[threedogs]

I like the inner guard theory as that would sound like what you describe but nowhere you will be looking, Might have broken a plastic plug on the dirt roads up there
Worth checking, Good call ROBO