Dumb Question Thread - No Flaming Allowed

[WestBankM4]

[QUOTE=Slideways;n220206]

I've got a leak in my sealed system, threw money at the problem and it didn't fix it. I plan on doing a smoke test soon, but damage to that hose or a leak it will trip code P0456: Evaporative emission control system leak (small)

I can smell fuel from time to time but I can't source it exactly, I really need to jump on that smoke test.

[Cubieman]

During the second angle (105°) torquing sequence of an M10 rod bolt I ran out of room and didn't quite get in one continuous swing, I got to 86° and finished it out with a second swing.

Using a 1/2" techangle wrench so it remembers where I left off, also I paint marked the collars on the bolts and they look identical in terms of amount of rotation.

Should I redo it (new bolts) to get a single 105° swing or leave it alone?


Also, another question, I noticed that on cylinder 5 the bearing doesn't want to sit totally flush on the cap, notice the small gap on the RH side. I tried two different new bearings with the same result.

The original bearing seems to have a very small gap as well but it's only maybe 1/3rd the size of gap as the new OEM bearings.

[Slideways]

During the second angle (105°) torquing sequence of an M10 rod bolt I ran out of room and didn't quite get in one continuous swing, I got to 86° and finished it out with a second swing.

Using a 1/2" techangle wrench so it remembers where I left off, also I paint marked the collars on the bolts and they look identical in terms of amount of rotation.

Should I redo it (new bolts) to get a single 105° swing or leave it alone?

In the service bulletin, BMW requires both the M11s and M10s to be torqued in one single stroke. Initially, I thought it was specific to the M10s due to the 3x tightening procedure, but the M11s require it too. Unless there is something special about this rod and bolt assembly, I'm not sure why it would be an issue to use the techangle feature to tighten it down in two passes. BMW is using a standard angle gauge and they possibly don't want a tech to mess up the angle by resetting the wrench. Because BMW adds the part about not adhering to the tightening specifications detailed below will result in serious engine damage, you might want to do it again if you have extra bolts.

In the DIS instructions, I believe Kaiv pointed out that the bolts could be tightened up to five times before needing to be replaced.

The rods are fracture cracked, so the surface will not be perfectly even side to side. Get the bearing seated as close as possible and during install, the bearings will find their place and crush against each other.

[bavarian3]

why is it called vanos "lockdown"

[Slideways]

why is it called vanos "lockdown"

Because there are a few key failure points and wear items that can all be addressed preventatively to make it reliable.

[zzyzx85]

any good tips on removing the valve cover studs on the front of the engine that hold the valve cover beauty cover? These seem to be made out of glass and I broke the top threaded portion off one this weekend after DIY'ing the valve adjustment. I was thinking of getting the car nice and warmed up before I attempt to unscrew the rest of it out.

Also, how does valve lash get tighter over time? I understand the lash opening up as the shim or valvetrain metal parts wears but lash getting tighter? Valve stems getting stretched? When I was doing my valve adjustment this weekend I noticed I was getting more tight than loose measurements.

[Tbonem3]

Tighter is bad, that means the valve is eating up into the head. As far as which side of things to land on if you can't get right in the middle in terms of adjustment spec, looser is better.

[Slideways]

any good tips on removing the valve cover studs on the front of the engine that hold the valve cover beauty cover? These seem to be made out of glass and I broke the top threaded portion off one this weekend after DIY'ing the valve adjustment. I was thinking of getting the car nice and warmed up before I attempt to unscrew the rest of it out.

Also, how does valve lash get tighter over time? I understand the lash opening up as the shim or valvetrain metal parts wears but lash getting tighter? Valve stems getting stretched? When I was doing my valve adjustment this weekend I noticed I was getting more tight than loose measurements.

Can you post a picture of the stud and how much of it is left? I'd think either a pair of vice grips or and bolt extractor might be good options.

The valve seat wears and causes the tighter clearance.

[zzyzx85]

Tbonem3 Slideways Thanks for the insight on the valve clearances. I did recall about aiming for the looser side of the tolerance range. Sounds like I should get a compression/leakdown test when I get a chance to.

Slideways: only the top threaded portion broke off. the entire nut portion is still there.

[Slideways]

Tbonem3 Slideways Thanks for the insight on the valve clearances. I did recall about aiming for the looser side of the tolerance range. Sounds like I should get a compression/leakdown test when I get a chance to.

Slideways: only the top threaded portion broke off. the entire nut portion is still there.

It should be easy enough to unthread it with a socket or wrench and install a new one.

[Tbonem3]

Now that I saw your pic in the other thread, I know what you're talkling about. People shear those studs off because they aren't aware that our valve cover is tightend down by "nuts" that bottom out. The rubber washers provide some resistence, so it might feel like a normal nut/bolt, but it's not. They go till they stop.

You should still be able to back it out with a 10mm no? From memory, there's a 10mm hex at the bottom of the stud, in order to drive the piece to secure the valve cover, the stud portion that broke off is just for the beauty cover. Need a deep well, thin 10mm. I actually had to sand my deep 10mm socket down to fit inside the "well."

[zzyzx85]

Slideways Tbonem3 right, i believe it is a 10mm. Just wanted to make sure it comes out easily and i don't snap off the other end, which would be a huuuuuuge pita to remove lol.

I don't believe I even reached the bottom of the thread when it snapped off. I noticed the other valve cover nuts stop when they hit bottom. So these 2 stop as well?

[Tbonem3]

It's been a while since I had one in my hand, but from memory, they're the same as the other 13 or whatever pieces around the cover, but these 2 at the front corners simply have a threaded stud on top for the front 2 chrome beauty cover nuts.

Better to shear the top stud portion - at least you can still back it out!

[PSUEng]

With regard to stock front calipers and carriers, I'm looking to replace the carrier mounting bolts. RealOEM lists two different carrier bolt part numbers of equivalent size:

34116767217 (Zinc)

34111156989 (black oxide)

Maybe over thinking this, but, the black oxide is significantly less expensive--but, the Zn will provide a better corrosion resistance. RealOEM lists both, and maybe Zn is better for salty conditions?? Thoughts?

[terra]

The zinc is probably more corrosion resistant. How much of a benefit you have and for how long... who knows.