[Eddien123]

Anyone know the valve cover bolt torque specs??

Engine is an N52. 2007 so bolts are steel not aluminum.

My valve cover says the following: "tightening torque fastening screws 8,6+/- 0,6 Nm"

I have no idea if that's referring to the valve cover bolts but if anyone knows for sure please let me know. I'm aware the N54/5 engines have a different torque spec (to my knowledge) but if for some reason you 335 owners know please reply.

[ctuna]

These are on use only Aluminum Bolts=N52.
There are numerous DIY's for this that have the spec.
Try Pelican Parts.
Eric the car guy has a great DIY on ytube for this with lots
of practical tips.
And there is a DIY sub forum here.
http://www.zpost.com/forums/showthread.php?t=1054136

[NOITALL]

Originally Posted by Eddien123

Anyone know the valve cover bolt torque specs??

Engine is an N52. 2007 so bolts are steel not aluminum.

My valve cover says the following: "tightening torque fastening screws 8,6+/- 0,6 Nm"

I have no idea if that's referring to the valve cover bolts but if anyone knows for sure please let me know. I'm aware the N54/5 engines have a different torque spec (to my knowledge) but if for some reason you 335 owners know please reply.

You just posted the torque yourself.
I'm confused.

Cheers

[OnlyDriveGerman]

Originally Posted by Eddien123

Anyone know the valve cover bolt torque specs??

Engine is an N52. 2007 so bolts are steel not aluminum.

My valve cover says the following: "tightening torque fastening screws 8,6+/- 0,6 Nm"

I have no idea if that's referring to the valve cover bolts but if anyone knows for sure please let me know. I'm aware the N54/5 engines have a different torque spec (to my knowledge) but if for some reason you 335 owners know please reply.

The numbers on the valve cover are correct. I just did the job, used Bentley as well as this forum of course and some YouTube vids. If you don't have blue paint on the top of the bolts, then you're correct, they are steel.

[ctuna]

Or somebody already did the job and the bolts weren't
painted. I have never heard of steel bolts on an N52.
at least on any part of the car that mates with the magnesium/Al
block.
Most of the head gasket kits from the better known places
come with the Al Bolts.

http://www.turnermotorsport.com/p-18...-e60-525i530i-

[OnlyDriveGerman]

The steel bolts would be significantly heavier, as well as magnetic. Aluminum is not magnetic.

[PhaseP]

2007 US N52 should have steel bolts, and reusable since not torqued to yield. This is because they have plastic (black) valve covers, and the bolts go into the head, which is aluminum, not magnesium. Steel into aluminum is ok as far as I know.

The engine block is magnesium alloy, so anything goes into block is required to be aluminum. But valve cover bolts go into head only.

2006 US N52's have magnesium alloy valve covers. Because the valve cover is magnesium they require aluminum bolts, and not reusable, even if the head is aluminum.

[ctuna]

Also some of the specs are torque + angle specs
I thought that the vcg bolt specs were x torque + 90 degrees
where I don't know what x is but I think it was 7 nm . And some
people hand torque these although I think that is kind of risky.

[Eddien123]

Thanks for your input everyone. I know I posted the specs and I sounded dumb but I was just confirming. Also for everyone's knowledge. U.S. spec N52 2007+ does in fact have steel bolts due to the block itself being a different metal than the 2006 models. My bolts did not have blue on them and I've owned the car since new so no ones touched them.

Thanks again for you're help!

[PhaseP]

All N52's have magnesium engine block, and also all N52's have aluminum engine cylinder head. First year N52's have magnesium valve cover, later year N52's have plastic valve cover. Because valve cover bolts only go into the cylinder head and not reach the engine block, the difference in valve cover bolt material between them is only due to the difference of the valve cover material, not the rest of the engine. In other words first year N52's require aluminum valve cover bolts only because they have magnesium valve covers. Plastic valve cover uses steel bolts.

Also note in all N52's the oil filter housing bolts are steel, because they bolt into the cylinder head, which is aluminum. But in all N52's the alternator bolts are aluminum because alternator bolts into the engine block, which is magnesium. The alternator pulley bolt is steel though, because it bolts into the aluminum alternator body.

That said some of the steel bolts that go into aluminum are still listed in Bentley manual to be replaced due to having some special coating and after one use the coat being scratched. The plastic valve cover bolts are not mentioned to be replaced in Bentley.

[lianke123321]

Man, there is so much information in your reply! Thanks!

Originally Posted by PhaseP

All N52's have magnesium engine block, and also all N52's have aluminum engine cylinder head. First year N52's have magnesium valve cover, later year N52's have plastic valve cover. Because valve cover bolts only go into the cylinder head and not reach the engine block, the difference in valve cover bolt material between them is only due to the difference of the valve cover material, not the rest of the engine. In other words first year N52's require aluminum valve cover bolts only because they have magnesium valve covers. Plastic valve cover uses steel bolts.

Also note in all N52's the oil filter housing bolts are steel, because they bolt into the cylinder head, which is aluminum. But in all N52's the alternator bolts are aluminum because alternator bolts into the engine block, which is magnesium. The alternator pulley bolt is steel though, because it bolts into the aluminum alternator body.

That said some of the steel bolts that go into aluminum are still listed in Bentley manual to be replaced due to having some special coating and after one use the coat being scratched. The plastic valve cover bolts are not mentioned to be replaced in Bentley.