Hmmmm,
I have a problem with my inlet manifold!!!

It is home built, but i get a massive resonance at 3500rpm +. It appears then to act as a musical instrument and plays an trombone type noise, which can not be reved out of..in fact a closed throttle will stall the engine in this condition.
I think i may have to somehow baffle the inlet plenum...
Seriously, has anyone else heard of or experienced anything like this????
I will try to make a recording so everyone doesn't think i am a complete nutter!!

Thanks
Simon
Rescued attachment manifold.jpg

Simon, Just had a thought have you tried it with the ISCV unplugged/blanked off it may be using the air bypass as a whistle.
Steve.

Cheers Steve,

I think i have tried that but i will check!!

PS its more of a a flugel horn than a whistle!!

In fact last time i started it i had the hounds running past the house followed by some men on horses in red coats!!!

[Edited on 13/5/06 by diyer]

Have you tried this.

My 2.0L zetec comes "on cam" at 3500-4000 rpm (nearer 4000 with my new cams). The engine note changes from growl to a very loud roar.

Other than trying to insulate the plenum I can't think of anything that will quieten it down without losing you power.

Thanks for that useful information STEVE!!

It might be different when i have some load on the engine.

Brilliant!!

It's probably the FIdle valve
Mine sounds like a moose on heat
It looks like you are using the Ford PWM one
In the original install they are fitted in such a way that they are muffled
The way we tend to fit them in our installs amplifies the buggers.
I've tried a VW Audi one and a Ford one and they're both as bad.
Hillarious

It only lasts for a short while though Till the cold start fast idle shuts off.




If you remove this plug it should stop it.
This will prove if it is the FIdle valve or not,

[Edited on 13-5-06 by BKLOCO]

[Edited on 13-5-06 by BKLOCO]


By the way.
Your manifold air intake is in the worst possible place
It will be sucking lovely red hot air straight from the radiator.
Definately not good.
To get the most out of your engine you need to get the coolest air possible.
If you can duct it in front of the rad it would be best

[Edited on 13-5-06 by BKLOCO]

quote:

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Originally posted by BKLOCO
Mine sounds like a moose on heat

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Well mine used to sound like a snake on smack.

now what the bloody hell does a snake on smack sound like, some sort of vague lethargic hissing sound?????

We used to call it Hissing Sid, it's calmed down a lot now though.

Wheezing Sid now then?

Mike,
I'm getting seriously worried about you
What are you doing with characuture pictures of a moose on your PC?

Brian, if I told you I'd have to kill you
Rescued attachment moose2.gif

quote:

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Originally posted by diyer
Hmmmm,
I have a problem with my inlet manifold!!!

It is home built, but i get a massive resonance at 3500rpm +. It appears then to act as a musical instrument and plays an trombone type noise, which can not be reved out of..in fact a closed throttle will stall the engine in this condition.
I think i may have to somehow baffle the inlet plenum...
Seriously, has anyone else heard of or experienced anything like this????
I will try to make a recording so everyone doesn't think i am a complete nutter!!

Thanks
Simon

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ok, sorted, it was the idle speed control valve causing the noise. So i will have to work on that after SVA!

Cheers
Simon

quote:

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Originally posted by diyer
ok, sorted, it was the idle speed control valve causing the noise. So i will have to work on that after SVA!

Cheers
Simon

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