Quote:
Originally Posted by masawyer
About 16 hours in and halfway through the procedure (bank 1 completed). I decided there is already a lot of threads covering this as well as some good videos on YouTube so I'm not documenting it.
I'm using the AGA toolkit to do it without removing the camshafts.
My e53 had really, really bad smoking issues with about 140k kms. I know there was a few threads on this site about other ways to fix the smoking or what really causes the smoking. I can say without a doubt that the stem seals are defiantly the cause. The (rubber) on the OEM seals in the engine are so hardened that they crumble and break when squeezed (one was cracked before I touched it, just the small spring holding it together) They have also been worn to a much larger diameter than the valve stems allowing the oil past.
I will post a couple of pics of my setup soon.
THIS IS ONE GRUELING JOB! #4 intake valve had me crawl right into the engine bay! Brutal! No wonder this is a $7000 job at the shop.
Anyone have any questions or tips, feel free.
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Mark, label, take pictures, notes, etc. When we do this job we usually do it with the engine outside of the car and the heads off so we always have a clean work space and are sure to label and mark everything so there isn't a shadow of a doubt when everything goes back together. I've never done this job with the engine in the vehicle so good job taking it on. Regardless of whether you do it in or out you have to pay attention, it is a lot of repetition but you can not get complacent with it. Sometimes when we do it at the shop we just have to walk away for awhile and clear our heads because of everything else going on in the background. I like getting it done early in the morning or even staying a little late when things are quiet and peaceful. Just take your time and be mindful and aware of what you are doing, if you need a break take one. Better to walk away and take a 10 minute break than try and struggle through it and end up making a mistake.
Quote:
Originally Posted by Motorsport1207
At some point in the near future I will need to do mine. I have heard opposing arguments on this issue.
1- The steam seals are not the cause, but a result of the guides wearing internally due to valve actuation not along the centerline. The original seals may be hard an brittle, but the smoke will return over time after new seals installation.( not sure how long).
2- the steam seals were not of the correct rubber material, as a result they become brittle and hard, thus leaking and smoking.
Ted
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Being that we do this job several times a year at the shop I work at I have to disagree with argument one. Done it enough times on long term customer vehicles who do bring their vehicles back to us but never for a smoking issue.
Argument 2 does have some validity to it. The seals may not be of the highest quality rubber so they do end up becoming brittle and hard causing an inadequate seal. But even more influential than the material is the maintenance of the engine, mainly I'm referring to oil changes.
This is from another thread I contributed in regarding engine oil in terms of both change interval and quality in regards to the N62.
For me the reasoning is fairly simple. I'd rather spend $50-$60 on an oil change every 5,000 miles than try and stretch it. In particular with the N62. I work at a shop while I am home between assignments and have worked on a lot of N62s in the past couple years. The ones with failing valve stem seals are the ones that also have sludge in them when we pull it apart from using cheap oil or failure to keep up with oil changes. The ones that are still running well are the ones we see every 5,000 miles for an oil change with a quality oil. Guy I work for has a 4.8is and both myself and his brother have 4.4i's all N62 motors, each of them have over 150k on the clock and they are all still going strong, no smoking, knock on wood.
People may underestimate or doubt the importance of maintaining a good oil change interval with a high quality oil but I've seen it prove its worth time after time. It becomes increasingly important when you start looking at newer engines that have more complex systems relying on engine oil to cool and lubricate them.