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Valve stem seals...becoming a normal thing

Discussion in 'Troubleshooting' started by [email protected], Nov 8, 2016.

  1. 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.

    Heres is what a leaking valve stem seal would like look wit has the turbos removed
    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.
    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.
    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.
    Last edited: Nov 8, 2016
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  2. foe516

    foe516 Lurker

    and how much does this usually run?
  3. About the same labor time as turbo replacement. It's a very tedious job.
  4. Nice work and setup! Really surprised that you do not see a lot more posted on this subject.
    So your looking at aprx 1k?
  5. Pending the shop rate yes something around that price.
  6. 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.
  7. 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.
    Last edited: Nov 8, 2016
  8. Awesome, thanks for the info
  9. Dave@Fuel-It!

    [email protected]! Corporal Vendor

    Mike- just curious the n54s that you've seen with this, what was the year/mileage? How many were VTA?
  10. VTA? As far as mileage it varies. We have seen 06-09s have this issue. Mileage varied from 60s-140k. Not any n55s yet, but all the ones we have done Ps2's on have been low mileage so far. (Sub 55k)
  11. Dave@Fuel-It!

    [email protected]! Corporal Vendor

    VTA - vent to atmosphere
  12. They were either stock pcv or BMS catch cans with RB valves
  13. @[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
  14. Hmm can't say I've had that issue or any issue yet with the tools.
  15. hmm. maybe we've just worn the dang thing out.
  16. Hm, Guess I'll check this while I do my single install in the next few weeks.
  17. doublespaces

    doublespaces Administrator

    2009 E93 335i
    Is there something which can be done to prevent this from occurring? What is the cause exactly?
  18. Unfortunately not, they wear out over time. Bmw had had this issue before with the N62 motor and very common on the n63 v8 twin turbo.
  19. doublespaces

    doublespaces Administrator

    2009 E93 335i
    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?
  20. ultimately, its the compound of rubber BMW used on these specific seals that cause the issue.