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High pitched sound coming from engine/intake area

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Old Dec 21, 2005 | 08:15 AM
  #1  
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Question High pitched sound coming from engine/intake area

This started a few days ago.. the car had been sitting out in the sun on a hot day for about 6 hours. I started the car and could hear this really high pitched sound - as you know with high pitched sounds its hard to pinpoint where they come from. (as you may know my cars been in a panel beater for past 3 months, so only been out for about a week)

I thought maybe it was the fuel pump as it tends to get noisier on hot days.. drove without too much hassle.

Start it up next morning, its whining again, this time I check it out and its coming out from under the bonnet somewhere around intake.

We had a look at it today, when we pour water over the engine it bogs down and revs low for quite some time..

Mate of mine said that this noise is often the sign of a rotor near death?? Hope not!

Anyway tonight I changed over the LIM gasket and put new O rings on primary injectors - will test it out in the morning,

just wondering if anyone has ever had this issue and what it could be?

Cheers,

Paul.
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Old Dec 21, 2005 | 09:36 AM
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something is definitely sucking air...

how does it run? any idle trouble or does it run like a clock save for the whistling?
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Old Dec 21, 2005 | 11:02 AM
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^I was thinking the same. Check for vaccum lines that may have been punctured or loose.
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Old Dec 21, 2005 | 11:34 AM
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Does the sound disappear when the engine is warmed up? If so, it could be a water pump bushing squealing. Check the weep hole for leaking coolant.
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Old Dec 21, 2005 | 12:40 PM
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It sounds like the water test found it's way to the vac leak.

Have a close look at the inlet duct from the AFM to the TB.
Cracks in the old hard plastic can hide until you pull it off & flex it a little.
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Old Dec 21, 2005 | 12:42 PM
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maybe it's electrical... check the coils

edit: is the sound there when the key is on / motor off?


does it get better or worse when the motor is reving?
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Old Dec 21, 2005 | 12:48 PM
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^^well you never know but I would rule it out for now^^

given that the car bogs when he wet it down - that would indicate it is sucking up water through either a lakey vac line, a worn/leaky gasket or some passage that leads IN to the motor...

if he had a high pitched squealing that was caused by electrical his thread would probably say...anyone known where to take a cremated carcass?
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Old Dec 21, 2005 | 12:51 PM
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^^^^^^^^^^^

Originally Posted by H4Inf
as you know with high pitched sounds its hard to pinpoint where they come from.

Cheers,

Paul.

???
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Old Dec 21, 2005 | 02:01 PM
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i encountere this same problem when i removed my uim.. turned out to be lod gasket i didnt remove causing a leak between the uil and lim.
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Old Dec 22, 2005 | 01:27 AM
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hey guys, thanks for all the feedback.

It wasn't feeling very responsive down low, but still over 5000rpm it was coming to life... anyway. I have solved the problem I think.

Last night I was fed up and decided to rip everything off the engine and put it all back on My UIM and LIM are welded together so no leaks there.

I replaced the primary injector seals/o rings (and noted that the old ones were about half the height of them). I also replaced the LIM gasket with one of the exact same type (3ply aluminium).

While I was at it, I decided to pull off the brake booster attachment to the intake and clean that up to ensure there were no leaks there. Put that back on and I think it went on tighter than before , as I could rotate it a bit beforehand.

I put it all back together about midnight and went to bed.

This morning I got up and started it, it ran about as smoothely as a rotary does on a cold morning, but I noticed the idle had dropped a fair bit.. I'm thinking this is probably because I have sealed up a vac leak? Maybe? Any ideas?
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Old Dec 22, 2005 | 08:03 AM
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Sounds like you got it.

Just a final tweak on the idle stop & TPS, and your goo to go..
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Old Dec 22, 2005 | 12:52 PM
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Originally Posted by H4Inf
Last night I was fed up and decided to rip everything off the engine and put it all back on My UIM and LIM are welded together so no leaks there.
Can you post a picture... I am wondering how they welded each port runner or do you make an aluminum gasket bolt it together and then weld it???? sounds interesting
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Old Dec 22, 2005 | 04:28 PM
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I have never recalibrated my TPS, I will do a search on it though.

Welded UIM to LIM:
http://rx7.pw.cx/photos/intake_leak_...leak%20040.jpg
and
http://rx7.pw.cx/photos/intake_leak_...leak%20046.jpg
and
http://rx7.pw.cx/photos/intake_leak_...leak%20042.jpg

All Pics from the teardown:
http://rx7.pw.cx/photos/intake_leak_21dec2005/

Thanks again guys

Last edited by H4Inf; Dec 22, 2005 at 04:30 PM.
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Old Dec 22, 2005 | 06:42 PM
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311unity13B's Avatar
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i had a high pitched squealing noise, about 2500rpm, and no idle, it was a blown intake gasket where intake meets with block
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