[Guest]

Any takers on this one:
Not the normal tappet noise - just to get that out of the way http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >

When the engine is cold at idle, sounds normal.
If I raise the revs normally the engine sounds normal.

However, if I blip the throttle quickly - generating positive boost on the boost gauge then it makes a very strange, slightly high pitched rattle. Its only a light sounds, not a deep grumbling you would get with a crank or similar.
I've had my head under the bonnet and bliped the throttle using the cable directly to try and trace the noise. It appears to be coming from the turbo or turbo area. IE definalty loudest with me ear-hole near the turbo (warm !)
If I allow the engine to warm thourghly (I.E. not just the water temp but long enough for the oil temp to get up as well) then it doesn't make this noise.

Oil has just been changed to a good quality semi-synthetic of the right grade (This is an Evo 1 by the way). It had started to make this noise prior to the oil change. Oil has been changed every 3k previously.
There is no smoke, power seems normal, no oil consumption to speak off.

So... what does anyone reackon ? Turbo bearing, or something worse. Or hopefully someone will say they had the same noise and it was a loose pipe (please [img]http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle > ) I suspect turbo as it only comes on as the boost gauge starts to generate positive boost - i.e. when the turbo is starting to be stressed. If I bring it up slooowly then there is no noise - that I can hear anyway.

Help appreciated fellas....

TonyC

 

[Guest]

That sounds like wastegate flutter , which can be caused by a weak wastegate actuator , does it hold boost ok?

 

[Guest]

Tony,
Are you sure it comes from the turbo and not the clutch area. Have a similar sort of noise and when i push the clutch in it goes away. The noise happens whatever the temp though. Been told its to do with arm in the clutch area just touching the clutch casing. Have talked about this on another thread, but carnt remember where it is or what its under.
Been told is nothing to worry about, think other people have this problem as well. Sorry i carnt remember what the exact cause of the problem is.
Cheers
Al

 

[Guest]

Had a good listen last night by the power of the very long screwdriver held against the engine. Difficult to track down but is not coming from the turbo.
Its not the release bearing in the clutch either - sorry Al.

The car wasn't on a ramp so it was hard to listen to the top and bottom of the engine to work out where it comes from. Boost is held ok so I'm going to pop down to the people who service it to see if we can work it out on their ramp.
Current possibilities so far range from piston slap (eek !) through a tappet being very weak and 'flying open' when the throttle is nailed to an injector 'fluttering'. It could also be something daft like part of the manifold loose/broken bolt. You can hear the noise along the fuel rail if you hold the screwdriver to the rail and your ear AND the fuel consumption has increased suggesting that perhaps an injector is weak and leaking.
When I discover what it is I will post it on hear with further symptoms for future reference.
Thats if the forum manages to not commit suicide again http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >

TonyC

 

[Guest]

Hi Tony,
I know this is nothing to do with your problem, but did you get that anti-lift kit from Oz. Have you fitted it, becuase since getting the full kit I have been getting a knocking-hollow kind of noise from the front suspension. Changed the top mounts but made no difference, noise is it there, getting worse. I was just wandering if it is the poly brushes on the lift kit rubbing? If its not this it could be something more sinisterhttp://www.ltregister.f9.co.uk/graphics/sad1.gif border|EQU| 0 align|EQU| absmiddle > and expensive[img]http://www.ltregister.f9.co.uk/graphics/sad1.gif border|EQU| 0 align|EQU| absmiddle >[img]http://www.ltregister.f9.co.uk/graphics/sad1.gif border|EQU| 0 align|EQU| absmiddle >, nothing changes[img]http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >
Any news on your problem,
Cheers
Al

 

[Guest]

Hi Tony,
Remove the induction pipe from the turbo, you should just be able to get your fingers in the check the endfloat and free play on the compressor shaft. There should no real movement either way, if there is then the blades may be hitting the turbo casing on either the compressor side or the exhaust side when load is starting to build up in the unit (not goodhttp://www.ltregister.f9.co.uk/graphics/sad1.gif border|EQU| 0 align|EQU| absmiddle >). Other than that make sure all the turbo heat shields are secure and free from rattles.
Regards,
Paul.C

 

[Guest]

Hi all, Al - I did get the anti- lift bushes but they don't appear to fit the Evo. Currently myself and a jap in Aud who bought them are helping whiteline to work out why not -as whiteline say they have had them fitted on CD lancers.

No 1 suspect on the sound so far is in fact a tappet ! After my posting title http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle > Its not in the turbo area at all - its loudest if you listen to the fuel rail whihc is mounted solidly to the cam carrier. Currently I've got it booked in for a check over. At the moment its perfectly possible for me to drive it without it making the noise so I should minimise any damager.
No 2 suspect is a cam follower slapping around.
It hasn't affect performance though : Over the weekend El' Evo gobbled up a Clio 172, Scoob WRX and a new model BMW 330i Sport [img]http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >

Yum, yum

TonyC

 

[Guest]

TonyC,

It's kinda far-off but it might be your A/C system. The magnetic bearing of the compressor isn't working properly anymore so the compressor is creating a clacking noise. Have the same probem with my E4. Just a though. Goodluck!

 

[Guest]

If noise is coming from fuel rail area and the engine layout is similar to the evo 6 it could be the valve which goes into the rocker cover. I think it is called the crank case pressure valve and to the left hand side at the back of the rocker cover on the evo 6 there is a little rubber pipe which just pushes into the rocker cover, there is a little piston in it, the actual noise sounds like something 'floating' about in the rocker cover or a tappet, sounds slightly higher pitched than a tappet. But sounds like it is coming from the fuel rail/cam cover area. If you can get it to rattle, get a pair of pliers and gently squash the pipe to block it off and then it should stop. Don't panic, its nothing major and cheap and amp; easy to replace.

If not, dunno!!!

 

[Guest]

Tony C,

If the noise is a light tinkling from the turbo area then the cause is a penny valve in the turbo housing.

My car does this...... Its a result of it not sitting 100%.....It can be solved by undoing the activator rod and turning it 1/2 a turn so that it is a little tighter. The only problem with this is that you get less control over boost and you will experience more overswing of boost levels.

Hope this helps

Jon

 

[Guest]

Thanks all, the car had its cam-belt changed the other day and they also checked out the source of this noise.
They are about 95% sure the problem is the exhaust/manifold/turbo area. They can not be exactly sure as they could not strip that section as I needed the car back the same day.
They think it is a very small blow on the exhaust area. Obviously as the car warms up the metal expands and the hole closers - hence it only does it when cold. Also explains the increase in volume as the throttle is pressed harder - more air flowing - as opposed to gently raising the revs -that doesn;t generate the noise.
After listening to it again it does sound like a very short, tight, chug chug. We did wonder about this when we first chcked.
The other noises were redherrings caused by my duff gearbox. the car is now about 70% quieter (at least !) than it used to be since the box was replaced. The thing must have been well knackered.
Seriously, you will not believe how much quieter the car is now when you stand next to it !

TonyC