Is it common for valve stem seals to fail on N55?

JohnelP · 01-15-2023, 10:55 PM

Hi,

Is it common for valve stem seals to fail on N55? Helping a friend with 2011 X5 N55 with a heavy oil fouled spark plug on cyl6 only. It triggers a misfire only on cyl6. The borescope cam showed oil on piston top. All other cylinders (1-5) seem normal. Will do a cyl leak down test these days with him to test the rings and valves proper seal, but wanted to understand this model "statistics" at 150k miles

Appreciate!

wcs531 · 01-16-2023, 07:35 AM

Not sure about the valve stem seals but the e70 in general has issues with the engine partition failing allowing water on the back of the engine causing issues with the ignition coils etc.

JohnelP · 02-11-2023, 01:53 AM

So, we decided to proceed with the valve stem seals on the N55.

I was thinking about the intermediate levers spring compressor(11 7 110). I see it is a large tool to compress those springs. Thinking out loud. What if I use a steel rope to pull the intake camshaft towards the center of the head, so i can keep the springs compressed? That way i can release the pressure on the intake camshaft bearing caps then remove the bearing caps, and slowly i can remove the camshaft while those springs will release tension( slowly)?

Or, like using a steel rope, with the eccentric shaft removed, grab the arms of the retention springs until no more pressure is put on the intermediate levers?

That may help during installing.. thinking.. Don't know, never tried, just asking.

Also, in the topic of asking, there is yet another specialty tool to preload the gate to the cyl head structure. - 11 4 450 - What is so special on that preload? Why can't i just push it while tightening the bolt? Or use some pliers? Is there any redefined force that needs to be applied and only that tool can provide it? Looks fairly basic

01-15-2023, 10:55 PM	#1
JohnelP Enlisted Member 4 Rep 35 Posts Drives: 5 Join Date: Oct 2020 Location: T iTrader: (0)	Is it common for valve stem seals to fail on N55? Hi, Is it common for valve stem seals to fail on N55? Helping a friend with 2011 X5 N55 with a heavy oil fouled spark plug on cyl6 only. It triggers a misfire only on cyl6. The borescope cam showed oil on piston top. All other cylinders (1-5) seem normal. Will do a cyl leak down test these days with him to test the rings and valves proper seal, but wanted to understand this model "statistics" at 150k miles Appreciate!
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01-16-2023, 07:35 AM	#2
wcs531 Second Lieutenant 97 Rep 281 Posts Drives: E90 335xi / E70 X5d Join Date: Jul 2014 Location: Philadelphia iTrader: (1)	Not sure about the valve stem seals but the e70 in general has issues with the engine partition failing allowing water on the back of the engine causing issues with the ignition coils etc.
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02-11-2023, 01:53 AM	#3
JohnelP Enlisted Member 4 Rep 35 Posts Drives: 5 Join Date: Oct 2020 Location: T iTrader: (0)	We''ll proceed with valve stem seals : Questions So, we decided to proceed with the valve stem seals on the N55. I was thinking about the intermediate levers spring compressor(11 7 110). I see it is a large tool to compress those springs. Thinking out loud. What if I use a steel rope to pull the intake camshaft towards the center of the head, so i can keep the springs compressed? That way i can release the pressure on the intake camshaft bearing caps then remove the bearing caps, and slowly i can remove the camshaft while those springs will release tension( slowly)? Or, like using a steel rope, with the eccentric shaft removed, grab the arms of the retention springs until no more pressure is put on the intermediate levers? That may help during installing.. thinking.. Don't know, never tried, just asking. Also, in the topic of asking, there is yet another specialty tool to preload the gate to the cyl head structure. - 11 4 450 - What is so special on that preload? Why can't i just push it while tightening the bolt? Or use some pliers? Is there any redefined force that needs to be applied and only that tool can provide it? Looks fairly basic
	Appreciate 0 Quote