M54 Madness, the remix

[Jaker]

Mine was single Vanos stuff, and the studs I used were significantly longer than the ones that were stripped. I might have been using intake studs. Either way it's fixed and that's all that matters. What did you end up doing? Helicoil?

[hoveringuy]

Done.

I pulled the radiator and hood for access, plus removed the VANOS unit.

The exhaust stud wouldn't have worked because the stud is an M6x60 and the exhaust stud is M7x39. I think it's the longest studs that pulled because they're clamping the thickest section of Aluminum, hence the greatest extra force from thermal expansion.


Seems fine now, anyway.

Edit: I helicoiled to use the original stud

[Jaker]

Edit: Oh, he's saying tap for M7 directly without using a helicoil.

:up:

[hoveringuy]

He is saying you can tap the thread from m6x1 to m7x1 with the vanos still attached.

Couldn't I do that with M6 as well?

Edit: Oh, he's saying tap for M7 directly without using a helicoil.

[digger]

He is saying you can tap the thread from m6x1 to m7x1 with the vanos still attached.

[hoveringuy]

I guess I'm not understanding the advantage of using M7 in place of M6.

[Jaker]

I'm just suggesting that the repair could be done by going to M7 without having to take apart the Vanos.

[hoveringuy]

I'm just saying the stripped stud at the VANOS is M6, my exhaust studs are M7 as you stated.

I have found helicoils to be strong with no limit to service life. I think repairing to M6 would be fine, and likely stronger than stock.

I had previously repaired a cam cap stud that pulled (overheated motor) the same way and it was fine forever.

[Jaker]

This one is M6 with a 10mm nut. (.23" stud diameter)

So just so we're on the same page here, I'm suggesting that you tap out the stripped M6x1.0 hole to M7 and use a stud from the cylinder head (all single Vanos M50/M52/S50/S52) where either the exhaust or the intake bolts to the head. Are you saying that the M54 uses M6s in those locations (the cylinder head where either the exhaust or the intake bolts to the head) or simply mentioning the size of the stripped hole for the Vanos?

[hoveringuy]

This one is M6 with a 10mm nut. (.23" stud diameter)

It takes me about 3 minutes to remove the radiator (after draining coolant), I'd rather make sure I do it right, but will try it without removing the VANOS first.

[Jaker]

yeah, I was wondering about that. I was planning on a helicoil. I'll need to remove the radiator for clearance, however. M6x1.0?

I edited my post above. Those studs with the 11mm nuts are M7. Not positive on the pitch, but I have the tap in my tap set, so I can confirm later today. And if memory serves me right, I was able to tap with the rad in place by using regular tools to turn the tap (small crescent wrench, small vice grips, etc...) rather than a tap handle. The hole is close enough size wise that no pre-drilling was required.

[hoveringuy]

Just tap the head right through the Vanos unit.

yeah, I was wondering about that. I was planning on a helicoil. I'll need to remove the radiator for clearance, however. M6x1.0?

[Jaker]

checked torque on the VANOS unit mounting nuts and one of them just kept spinning...

Been there done that with my M50 cylinder head. The holes in the Vanos unit are big enough for M7 studs (think intake and exhaust manifolds at the head). Don't even have to take the Vanos unit off. Just tap the head right through the Vanos unit.

[hoveringuy]

Crap. I've had a small oil leak coming from my VANOS area. Checked the usual suspects and they were fine, checked torque on the VANOS unit mounting nuts and one of them just kept spinning...

[wazzu70]

Small update. I installed a metal M56 valve cover. The plastic M54 one can crack and leak, a new one is $379. The M56 cover will never crack and has robust oil vapor separation built-in, plus it simplifies coils to the later pencil design. (no more bolts!).

I always find it amazing the m56 was good for something afterall!!