valve spring change?

coloradoe92m3 · 07-07-2014, 11:03 PM

Forgot to ask this, at 100k would changing valve springs be good investment given these high revving motors must stress springs? I've spent a lot of time above 7500rpms. Is this a big job?

s85e90 · 07-08-2014, 06:56 AM

No unless they need changing its a waste

apecush · 07-08-2014, 01:45 PM

At 100k miles, you are well over 10^8 cycles on a valve spring. As this is beyond the fatigue limit of most steels, it is very improbable that a spring would ever fail. Any manufacturing flaws would have either caused a failure well before 100k, or will remain dormant for the balance of the life of the engine.

BPMSport · 07-08-2014, 02:18 PM

Quote:

Originally Posted by apecush

At 100k miles, you are well over 10^8 cycles on a valve spring. As this is beyond the fatigue limit of most steels, it is very improbable that a spring would ever fail. Any manufacturing flaws would have either caused a failure well before 100k, or will remain dormant for the balance of the life of the engine.

x100.

Most spring failures I've seen have been on lower mileage cars.

edwinm3 · 07-08-2014, 04:08 PM

If it ain't broke don't fix it

IMG · 07-08-2014, 04:22 PM

Quote:

Originally Posted by edwinm3

If it ain't broke don't fix it

+1

coloradoe92m3 · 07-08-2014, 06:55 PM

Thanks guys! I've had 85k no engine prob mikes tuned with hard driving and want to enjoy 85k more!

s85e90 · 07-08-2014, 06:56 PM

Quote:

Originally Posted by coloradoe92m3

Thanks guys! I've had 85k no engine prob mikes tuned with hard driving and want to enjoy 85k more!

Springs don't go bad. Same as your suspension springs. "Spring" steel should last forever unless defective.

Edward · 07-28-2015, 03:58 PM

My car has something going on in cylinder 7 and they are opening it up today at 22k miles. I think it may be a broken valve spring considering it wasn't ignition coil or fuel injector. Would be totally lame if it were. I haven't had my car since Friday and I I'm losing my mind in this loaner.

07-07-2014, 11:03 PM	#1
coloradoe92m3 Banned 40 Rep 496 Posts Drives: m3 Join Date: Mar 2014 Location: u.s iTrader: (0)	valve spring change? Forgot to ask this, at 100k would changing valve springs be good investment given these high revving motors must stress springs? I've spent a lot of time above 7500rpms. Is this a big job?
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07-08-2014, 06:56 AM	#2
s85e90 Brigadier General 203 Rep 3,633 Posts Drives: black e90 Join Date: Jan 2014 Location: everywhere iTrader: (2)	No unless they need changing its a waste
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07-08-2014, 01:45 PM	#3
apecush Lieutenant 31 Rep 526 Posts Drives: 2008 E90 M3 Join Date: Aug 2011 Location: Edmonton iTrader: (2)	At 100k miles, you are well over 10^8 cycles on a valve spring. As this is beyond the fatigue limit of most steels, it is very improbable that a spring would ever fail. Any manufacturing flaws would have either caused a failure well before 100k, or will remain dormant for the balance of the life of the engine.
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07-08-2014, 04:08 PM	#5
edwinm3 Brigadier General 1053 Rep 4,035 Posts Drives: F82 Join Date: Nov 2011 Location: Broward iTrader: (32)	If it ain't broke don't fix it __________________ Grigio Telesto M4, 6MT. Coyote 5.0 F-150 991 GT3
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07-08-2014, 06:55 PM	#7
coloradoe92m3 Banned 40 Rep 496 Posts Drives: m3 Join Date: Mar 2014 Location: u.s iTrader: (0)	Thanks guys! I've had 85k no engine prob mikes tuned with hard driving and want to enjoy 85k more!
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07-28-2015, 03:58 PM	#9
Edward Colonel 391 Rep 2,983 Posts Drives: 2013.9999 E92 Jerez ZCP Join Date: May 2010 Location: Los Angeles iTrader: (2)	My car has something going on in cylinder 7 and they are opening it up today at 22k miles. I think it may be a broken valve spring considering it wasn't ignition coil or fuel injector. Would be totally lame if it were. I haven't had my car since Friday and I I'm losing my mind in this loaner.
	Appreciate 0 Quote