Strange air intake sound

[MinniTheMoocha]

Just trying to get to the bottom of an air intake sound that has become more pronounced.

If you put you ear up to the air ram on the snorkel you are getting a whoop whoop whoop type of sound.

I listened to BrendanB's today and his just sounds like air being sucked straight in nothing else.

What's interesting is the sound is very much as if you removed the top hose from the intercooler and just allowed air to be sucked straight into the air intake manifold, this really makes a loud whoop whoop sound. I have checked all hoses after the turbo and will check all hoses before turbo including air filter tomorrow.

Not sure if I should be worried or not but if there are any thoughts on this it would be appreciated.

If needed I can record a small video and try capture the sound as I have done my best trying to describe it.

Thanks

MtM

[justinc]

Yours must be a Tdi, this will be the loose tappet syndrome noise, try a valve adjustment:) You will have at least 3 or 4 loose valve clearances. 0.208mm (.008") inlet and exhaust, cold or hot.

JC

[MinniTheMoocha]

Thanks Justin under the bonnet now so will check clearances

[dullbird]

Failing that

I would guess check your ducking for you snorkle doesn't have a small split in it somewhere too.

[Madana]

Sounds as is some of the valve caps have worn away or become dislodged through to much clearance

[MinniTheMoocha]

Well the verdict is in.

Tappets were way way out. In fact one of the end caps has bounced off!

Was able to replace all the valve end caps and then reset all the valve clearances.

It's amazing what plays on your mind as you make allowances for extra motor noise, loss of power and lowered fuel economy.

Was put on to the possibility of loose rocker shaft / tappets by Steve last week but essentially dismissed it having rebuilt the top of the motor only a year ago. I rechecked tappets 1000km after the rebuild which only needed minor adjustments to be made. I haven't really done more than 10,000km so tappets are normally done around every 20,000km so was waiting until I reached that distance. Not good!

Yesterday Steve heard me pull in the driveway and said "you better pull the rocker cover off tomorrow" which I was not keen to do as I had worked with Steve on BrendanB's car most of the afternoon and didn't want to upset SWMBO who was layed up sick in bed and should have had more TLC rather than the car! :-)

Well I am glad I did open the bonnet! So thanks to all who replied and also to Steve for his expert guidance.

MtM