N62 engine valve stem seals

[mr_robot]

Yea my receipt shows N62TU valve stem repair kit. Bought it at a local BMW dealer as the Indy mech gets discounts there.


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[X5only]

Originally Posted by jpcallan

Actually, there is no danger of a keeper, etc. falling into a cylinder as I faithfully used the black plastic spark plug hole guides provided with the AGA kit and the flag rod to plumb the piston TDC position, as well as faithfully using the AGA cam chain lock tool to prevent crank shaft movement. With the rope/bungy method there still exists the risk of dropping a valve into a cylinder when backing off the the piston a bit so the valve can extend into the cylinder to put the rocker arm back in place.

You raised the issue of the camshaft balancing lobe on cyl #2. I did the valve stem seals on an 2008 X5 with N62TU engine; #2 had no balancing lobe as described in the AGA Kit manual, but did have a balancing weight lobe on #7 that I had to work around. I've not seen anyone else describe this anomaly, but did confirm it with AGA tech support. AGA's instruction manual is indeed in need of some updates and revisions.

No, not falling into the cylinder but into the depths of the engine through the wide gaps around the timing gears - it's pretty obvious. If a keeper falls in there, it may be impossible to get it out without disassembling the lower timing case!

As for your assertion of the risk of the valve dropping when backing off the piston to install the rocker arm back, the valve spring and its keepers are already installed at this point so it's impossible for the valve to drop as long as you keep pressing down on the valve as the spring is compressed, the same thing you're to do when using air pressure or nothing at all! The only risk I see with a rope is it getting stuck due to forming a knot. For this reason a bungee cord is the way to go.

[jpcallan]

Originally Posted by X5only

No, not falling into the cylinder but into the depths of the engine through the wide gaps around the timing gears - it's pretty obvious...

Sorry, I misunderstood where you were suggesting pieces might get lost. Another member somewhere warned of the danger of exactly that route of entry into the engine, so I heeded his wise advice by packing red cloth shop rags around the timing gear and chain. This route of stray parts entry is a risk whether one uses compressed air, rope/bungy or no combustion chamber filler.

An additional choice I made to minimize the risk of foreign material of any kind entering the engine was doing one cylinder bank at a time. I did my job outdoors in the driveway. I tarped the car at night and pulled 32" stretch-wrap over the hood to windshield gap to keep any rain/dust out.

[X5only]

Originally Posted by X5only

Valve stem seals done! Engine timing perfect. Buttoning up the engine now after replacing all other seals and gaskets.

Late update

NO SMOKE !!!!!!!!!!!!!! Took her for a long drive, idled for 45 minutes until I got tired . Wow, what a feeling it was to see no smoke after revving hard . It took about 100 miles of driving for the stinky exhaust smell to completely go away. But the smoking stopped immediately . I also did an oil service with BMW performance oil, getting ride of the heavy oil and lucas additives I'd been using.

For those who believe it's vacuum leaks causing the smoke and therefore only go as far as replacing the valve cover gaskets and the associated seals, I'd recommend to go all the way and replace the valve stem seals as well because you've already done most of the work anyway, and it's not like the valve stem seals last forever. It's what finally stopped my smoking issue after earlier on wasting time and money replacing both valve cover gaskets and seals. And for those hesitating to do this project, if you can replace the valve cover gaskets, the valve stem seals replacement is very much within your skill level. Go for it! Using a bungee cord, instead of an air compressor, certainly makes the project much, much easier, safe and you can take your sweet time working without being a noise nuisance. Some say it can be done without a compressor or cord; indeed you can since all is needed is to make sure the cylinder you're working on is at TDC, but for the average DIY'er tackling this project for the first time, better to play it safe and sure … your choice

[SlickGT1]

Great job. This is in store for me.

[Westlotorn]

Glad you got yours fixed. Aren't these x5's fun to work on! Great car, not easy to work on.

The FIRST thing to check for anyone considering this job is the vent hoses where they enter the front of your intake manifold by the throttle body. A vent hose comes from each valve cover, these hoses on my 08 4.8L meet in the middle at a T and one hose connects to the Intake Manifold. Pull this hose and inspect. If OIL is in this hose and you see oil inside your intake when you shine a pen light into the connection for this hose you have a Vacuum leak. Nothing else will put oil into these hoses or the manifold. Nothing. You would see a minor amount of oil from the vapor in the hoses but no running or dripping oil in a good engine.
The fact that your car had stinky exhaust for 100 miles indicates your manifold probably had residual oil in it and most of it cleaned up over time.
With a reduced amount of oil coming in your Cats would have burned it up giving you clean looking exhaust. A greater amount would smoke out the back.
Even with the manifold off the car it is hard to wash all the oil out.
I think I washed mine with Diesel fuel first and then hot soapy water before putting it back on.
With the Manifold off the car you can inspect the Intake Valves, they should be clean and pretty dry, if a valve stem seal has been leaking enough to make the engine smoke you will see wet oil on the intake valve heads looking down the intake ports.
If the oil is coming down from the manifold rather than the valve stem seal you will see the oil path going down the intake ports. The should be clean aluminum.
You are correct that while in there, installing new valve stem seals is not that much more work or expense over doing just the gaskets.
I have only fixed 3 of these, a 4.4, 4.6 and my current 4.8L, have not needed valve stem seals yet. One was repaired at 140K and is now over 200,000 miles.
The 4.8L is only at 115,000 after being repaired at 90K, no longer leaks or burns oil.

The best side effect was how well the tranny shifts once the air leaks are plugged.
It shifts like brand new again. If your throttle is a little jumpy coming off idle in first gear that is an indicator.

[Baby Unicorn Taco]

Originally Posted by Westlotorn

Glad you got yours fixed. Aren't these x5's fun to work on! Great car, not easy to work on.

The FIRST thing to check for anyone considering this job is the vent hoses where they enter the front of your intake manifold by the throttle body. A vent hose comes from each valve cover, these hoses on my 08 4.8L meet in the middle at a T and one hose connects to the Intake Manifold. Pull this hose and inspect. If OIL is in this hose and you see oil inside your intake when you shine a pen light into the connection for this hose you have a Vacuum leak. Nothing else will put oil into these hoses or the manifold. Nothing. You would see a minor amount of oil from the vapor in the hoses but no running or dripping oil in a good engine.
The fact that your car had stinky exhaust for 100 miles indicates your manifold probably had residual oil in it and most of it cleaned up over time.
With a reduced amount of oil coming in your Cats would have burned it up giving you clean looking exhaust. A greater amount would smoke out the back.
Even with the manifold off the car it is hard to wash all the oil out.
I think I washed mine with Diesel fuel first and then hot soapy water before putting it back on.
With the Manifold off the car you can inspect the Intake Valves, they should be clean and pretty dry, if a valve stem seal has been leaking enough to make the engine smoke you will see wet oil on the intake valve heads looking down the intake ports.
If the oil is coming down from the manifold rather than the valve stem seal you will see the oil path going down the intake ports. The should be clean aluminum.
You are correct that while in there, installing new valve stem seals is not that much more work or expense over doing just the gaskets.
I have only fixed 3 of these, a 4.4, 4.6 and my current 4.8L, have not needed valve stem seals yet. One was repaired at 140K and is now over 200,000 miles.
The 4.8L is only at 115,000 after being repaired at 90K, no longer leaks or burns oil.

The best side effect was how well the tranny shifts once the air leaks are plugged.
It shifts like brand new again. If your throttle is a little jumpy coming off idle in first gear that is an indicator.

^ This is a good paragraph of information for anyone first trying to figure out their N62 oil/smoke issues. Someone could search multiple threads for hours trying to find what Westlotorn just stated. Simple, to the point, Well said.

[Anshev]

Originally Posted by X5only

Late update

NO SMOKE !!!!!!!!!!!!!! Took her for a long drive, idled for 45 minutes until I got tired . Wow, what a feeling it was to see no smoke after revving hard . It took about 100 miles of driving for the stinky exhaust smell to completely go away. But the smoking stopped immediately . I also did an oil service with BMW performance oil, getting ride of the heavy oil and lucas additives I'd been using.

For those who believe it's vacuum leaks causing the smoke and therefore only go as far as replacing the valve cover gaskets and the associated seals, I'd recommend to go all the way and replace the valve stem seals as well because you've already done most of the work anyway, and it's not like the valve stem seals last forever. It's what finally stopped my smoking issue after earlier on wasting time and money replacing both valve cover gaskets and seals. And for those hesitating to do this project, if you can replace the valve cover gaskets, the valve stem seals replacement is very much within your skill level. Go for it! Using a bungee cord, instead of an air compressor, certainly makes the project much, much easier, safe and you can take your sweet time working without being a noise nuisance. Some say it can be done without a compressor or cord; indeed you can since all is needed is to make sure the cylinder you're working on is at TDC, but for the average DIY'er tackling this project for the first time, better to play it safe and sure … your choice

Ready to sell the tool? ...I am planning to do this job on 2009 X5 4.8 with 86k

[stiubhartach]

Originally Posted by Unicorn

^ This is a good paragraph of information for anyone first trying to figure out their N62 oil/smoke issues. Someone could search multiple threads for hours trying to find what Westlotorn just stated. Simple, to the point, Well said.

Excellent information. Thanks!


I just had another round of smoking problems during a smog test. It was failing the 'snap test' where the engine is revved to 3k RPM three times with visual inspection of smoke from the tail pipe.


It was smoking again, after rebuilding and cleaning the CCV system and the intake manifold two year ago. I was hoping it was the CCV system again and not the valve stem seals finally.(I haven't had to do them yet, at 160k)


Fixed: It was the CCV system again.

• Changed the diaphragms in the valves covers and cleaned both the hoses.
• It was still smoking, so there must be oil still in the intake manifold.
• Plugged both CCV hoses with silicone stoppers.
• Sprayed a can of carb cleaner into the hose inlets and into the throttle body on the intake manifold while the engine was running.
• Drove on freeway for half hour.
• Passed test perfectly

Note: The CCV hoses are to collect the blowby gasses from the crankcase. Plugging the hoses is OK short term, but would lead to a build up of water and crap in the engine oil.


Here's my thread detailing my initial fix:


https://xoutpost.com/bmw-sav-forums/...lem-fixed.html

[blktoptrvl]

OK, it's my turn.

145,000 Miles. I noticed puffs of smoke when idling. I have already replaced the PCV Caps and diaphragms - no soap. When I got home today, I let the car idle and for about 4 minutes there was no problem. Then a little smoke started flowing from the left exhaust. a minute later it was also flowing from the right. Another minute after that it was like a bug fogger went off.

So, if I look for a used AGA tools kit, is there anything in the kit that could be damaged or bent and therefore make the kit not worth the money?