Valve stem seals...becoming a normal thing

Nov 8, 2016
17
McHenry, IL
We are on our tenth n54 that is in need of valve stem seal replacment this year. It seems like it's becoming the norm for higher mileage n54s. 70k miles and up. We have been getting quite a few smoking n54s, not all have just been valve stem seals, but upon removal of the turbos we have seen about 80% of the cars needing them that come through our shop.

20161108_065629.png

Heres is what a leaking valve stem seal would like look wit has the turbos removed
20161108_065724.png

Special tool needed to release tension of the valve springs so the cam can be removed, without this you run a risk of cracking or damage.
20161108_065704.png

Shop air is forced into the cylinders to keep the valves in place sof once the keepers are removed it does not fall into the cylinder.
20161108_065646.png

Our special tool needed to be able to replace them in the vehicle, the conventional way is removing the whole head and doing it on a bench or such.
 
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Nov 8, 2016
17
McHenry, IL
I plan on doing this at some point this winter. @[email protected] is there specific symptoms you have found that are associated with these requiring replacement? I was going to do them as PM, but the only time I get smoke is decel conditions.
That is usually the complaint we get. Smoke upon coming to a stop. We have had this complaint were it turned out needing turbos as well though. The only issue with doing the valve seals in the car this way is you can't technically check the guide itself for wear. If the actual guide is worn replacing just the seals is like a band aid. They will go bad again fairly quickly. Problem is the only way to test the guides is pulling the head and using a brand new valve and checking movement. Which is why not many people check the guides themselves. We have only seen one senerio were the guides were faulty.
 
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[email protected]

Corporal
Platinum Vendor
Oct 25, 2016
149
Houston, Texas
@[email protected] does your valve depressor tool "stick"?
We (obviously) have the same tools to do similar jobs, but man it ticks me off the dang finger that pushes down the two rockers will bind on the guiding shaft (the rod right next to the bronze nut) and sometimes it's a bear to get it to release.... pain in my neck lol
 
Nov 8, 2016
17
McHenry, IL
@[email protected] does your valve depressor tool "stick"?
We (obviously) have the same tools to do similar jobs, but man it ticks me off the dang finger that pushes down the two rockers will bind on the guiding shaft (the rod right next to the bronze nut) and sometimes it's a bear to get it to release.... pain in my neck lol
Hmm can't say I've had that issue or any issue yet with the tools.
 

doublespaces

Administrator
Oct 18, 2016
8,869
AZ
Thanks for the reply. So what is it about the engine or the seals which cause this to happen on these motors but not others? Or is it just unknown?
 

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