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[claydoc]

I was driving along when without any warning, a major drop in power and a very bad sounding engine…? Stopped the car ASAP and checked under the hood, nothing out of place here? Restarted the engine and the bad sounds from the engine again… I thought I may dropped a valve. !@##$%

Put car on a tow truck and took home. Removed cam cover and spark plugs, checked all valve clearances and compression tests all OK???? The noise was coming from the top of the engine so I assumed the Turbo and waste gate systems all OK. I just happened to bump the top of the throttle body when putting back the cam cover and the 2 springs and throttle cam assembly went flying across the garage ?????? (What The!)

On closer inspection found the butterfly valve shaft on the throttle body had broken in the little screw hole that holds the butterfly valve onto the shaft. But of course where was the missing little screw? Yep you guessed it inside the engine! @#$%^&* (Number three cylinder) The good news is that it has not damaged anything (Head or piston) just the cost of removing / replacing the head back on the engine.

What is the cause of this? The throttle cable was too tight before I got the car and it had worn out the bearings in the top of the throttle body which put too much pressure on the butterfly shaft and over along time broke it.

Check your cables and TB bearings out ASAP

Regs Chris
_________________
Go racing .. It's fun!

[Raceboy]

thanks for the warning. Did that in the morning, luckily everything was ok
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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[924guy]

wow , that sucks..thanks for the heads up, just added to my to-do list...

are these supposed to be loc-tite'd in? if so, it occured to me that there might be an age limit for loc-tite or similiar stickies...could be an issue for those of us who have original engines that havent been rebuilt...
another thought in ref to the pistons thread, im wondering if flat tops would have been as toarant of that little screw?
_________________
Eric
78 924
82 931 SE "smokey"
99' VehiCross
Y2K Honda Insight
http://www.cardomain.com/id/924Guy
Performance by Pasha

[claydoc]

Thanks guy's ..

Looking at what's is to stop these screws coming out on the two TB's that I have looked at is the end of the screw is burred over or center punched out, but remember mine broke because the top bearing was RS and this broke the shaft which let the screw fall out into the inlet manifold... So check ya bearings dudes.

Yep it would have been a disaster if the piston were flat!

Regs Chris
_________________
Go racing .. It's fun!