Engine fault 2.4T

[moriarty]

Hi My engine (2.4T) has developed a strange rattle/ tapping noise at low revs which all but disappears at about 2000rpm. On start up from cold it seems normal but after about a minuet it starts the noise, it doesn't misfire and pulls well through the rev range. I have eliminated the alt bearing by removing the fan belt and someone suggested it could be broken bob weight springs in the dizzy, is this likely to make this noise?
One other point, the noise seemed to appear about 5miles after running through a deep puddle of water but this may not be relevant.
Anyone got any other thoughts before I pull the engine out?
Moriarty

[911hillclimber]

Just my 2d:
Check the chain tensioners?

[moriarty]

Thanks for your 2d, I have pressure fed tensioners fitted and v/good oil pressure but to check them on a 914/6 means engine out
M

[911hillclimber]

I've had one of those fail and the clatter was disturbing.
Hope it is something much simpler.

[bjmullan]

Have you tried using a stethoscope? You can get mechanical ones which may help to isolate the area. I have one if you want to borrow it.

[moriarty]

Thanks for the tip/offer Brendan, just ordered one off ebay!
Maurice

[Robster]

Hi Maurice, mine does somethings very similar. I can't remember if you are running carbs or injection, but mine is caused by some wear in the bushes on my carbs allowing the throttle plates to move slightly and 'flutter' against the Carb body. On wider throttle openings it goes away as the throttle plate moves away from the carb body at wider throttle openings. Makes a ticking/tapping sound not unlike a valve that needs adjusting at idle. I know it is this because if Hold the end of the carb spindle I can feel a little bit of play and the noise goes away.

That is one of my worst descriptions ever, but hope that makes sense!

Just a thought...

[moriarty]

Hi Rob
Thanks for your reply, I will check the carb bushes but have now narrowed the noise down to RH timing chain cover so am suspecting tensioner collapse as others have suggested although they were replaced by the PO and have only done about 24k since!
Maurice

[911hillclimber]

My LHside failed just over 1000 miles after fitting....they were the 3.2 type though.

[KS]

Thanks for your 2d, I have pressure fed tensioners fitted and v/good oil pressure but to check them on a 914/6 means engine out
M

Russell Lewis installed pressure-fed tensioners on my 914/6 with the engine in place...

[911hillclimber]

Yes, replaced mine that way, silencer off, rest was easy.

[moriarty]

Hi Keith
Would you like to come and do mine? I need to check v/clearances and address a couple of niggling oil leaks etc so engine out anyway.
Handy to know it can be done in situ.
Cheers
M