Ticking noise at idle - fresh rebuilt motor

adampecush

Regular Supramaniac
May 11, 2006
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So I've recently finished the complete rebuild of the 7M in my car. Among some of the other issues (specifically, camshaft seals that won't seal), the car has a rattle/tick at idle. The following describes the characteristics of the noise

Sounds similar to clutch chatter from a lightweight flywheel (which the car has, as well as an ATI pulley), but doesn't go away when the clutch pedal is depressed
Sound is absent above around 1100-1300 rpm and doesn't seem to get louder with increased revs
Sound is most pronounced when standing beside the car, behind the front axle, driver side or passenger side. Much quieter under the front end of the car
Checked for rod bearing issues by pulling plug wires to see if the noise stopped. It did not.
My valves are about .001-.002 above max spec to allow them some space to bed in. The fact that the sound is louder at the sides of the car versus with the hood up tells me that it is not valves.
External wastegate is not leaking
Motor makes 10 psi at warm idle, and around 45 psi at 2500 rpm.

I'm pretty stumped. Next thing I'm doing is pulling the clutch inspection covers to see if there is anything strange going on back there. Maybe a broken flywheel bolt?

Any other suggestions?

Thanks!
 

adampecush

Regular Supramaniac
May 11, 2006
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IndigoMKII;2025857 said:
Noisy injectors maybe

the injectors can be heard from the engine bay - they tick, but I'm fairly certain they're not the source of my issue. I'd think the noise would be the loudest when looking under the hood. It's not, it is most obvious with the hood closed and from the side of the car.
 

supranewbie

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Mar 23, 2011
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I'd be pulling those inspection covers. Water pump can get noisy, but you'd be able to hear it up front. Sounds like you've verified most everything that could sound like what you describe. Couldn't be an exhaust leak?
 

Suprapowaz!(2)

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Apr 10, 2006
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Any of the accessory or idler pullies? You can pull one belt off at a time and run it to see if noise goes away. It'll be kinda hard to test the timing belt idler pulley though.
 

adampecush

Regular Supramaniac
May 11, 2006
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supranewbie;2025878 said:
I'd be pulling those inspection covers. Water pump can get noisy, but you'd be able to hear it up front. Sounds like you've verified most everything that could sound like what you describe. Couldn't be an exhaust leak?

That's the one thing I haven't been able to confirm/eliminate. Very possible, I'll have to dig further into it. Thanks.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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super51fan;2025969 said:
What about valve clearance causing the tick. I usually set them close to min when adjusting the valve clearance. Or in the middle on new set up.
bzzz wrong... ;)

The Gap closes down as the Valve "sinks" on the seat so it you set to minimum you end up with 0 lash or a hung open valve when at operating temp..
 

super51fan

New Member
Jul 28, 2010
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So 1j is saying that valves "sinks" .008" I don't thinks so. Maybe .001" or .002" . Ill stick with setting a running engine to .006" on intake and .008" on exhaust and .008"in and .010"ex on new set up.
 

hvyman

Dang Dude! No Way Man.
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Apr 17, 2007
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You were still wrong. When the valve sinks and you already at the min your below spec when it does.

And 7m have a pretty noticeable valve tick even when in spec...
 

adampecush

Regular Supramaniac
May 11, 2006
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If the tips of the valves wore, setting them at minimum clearance would make sense. The reality is that the wear happens between the valve and the seat, causing a reduction in clearance between the shims and cams.
 

super51fan

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Jul 28, 2010
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The word "running" meant a valve adjust as part of maintenance. "New" as is a new setup with new valves or valve job. I stick by what I said. IF your valve "sink" more than .002" you are doing something wrong. A 7M set at min valve clearance specs are quiet. IMO
 

IJ.

Grumpy Old Man
Mar 30, 2005
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Never said ANYTHING about the Valve sinking 8 thou... and people wonder why I don't bother helping here as much as I used to...

AGAIN if you set the lash to MINIMUM on a new valve job then when the engine is at OPERATING TEMP you run the risk of hanging the valve off the seat and torching it...

The stock SPEC is set around the amount that the Valvetrain expands when hot to ensure the above doesn't happen....

Seriously it's not Rocket Surgery... :nono: