RTV with valve cover.

pysical

Sergeant
Jun 16, 2017
352
76
0
Ride
2009 335xi E90
Has anyone put a bead of rtv around the gasket of the valve cover? I have a new valve cover and gasket and it has held up fine for about 500 miles. Then I recently just let the car sit for about 6 days and since then I can smell burning oil. I took a look and it appears it is leaking into downpipes. I am not sure if running higher boost would be causing any sort of issue? I was thinking about putting on some RTV to just help seal it a little better.
 

1and1

Specialist
Dec 28, 2016
60
34
0
Tally, FL
Might just need to re-torque the VC bolts. Had to with mine after about a week (~200 miles worth of daily commuting to & from the office), been fine ever since, ~4,000 miles now and dry & clean.
 
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pysical

Sergeant
Jun 16, 2017
352
76
0
Ride
2009 335xi E90
Might just need to re-torque the VC bolts. Had to with mine after about a week (~200 miles daily commute to office), been fine ever since, ~4,000 miles now and dry & clean.

It leaks around number 6, and around 4. The two most common leaking spots. The valve cover should not be cracked. I tried to tighten them down around 4 and they were pretty snug. I didn't try on the rear bolts though. I will check them out though.
 

fmorelli

Major General
Staff member
Aug 11, 2017
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You should only ever need dabs of RTV on a cam cover at corners or transition points (i.e. timing cover to head mating), YMMV depending on what car your working with (beyond N54). Torquing again is highly recommended - these are low torque applications, and over rubber it's looking to compress, move around, and lose torque on the head. With modern cars I think it is exceptionally wise to own a good quality 1/4" torque wrench. I use the Wera 1/4" torque wrench and recommend it.

Filippo
 
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The Convert

Captain
Jun 4, 2017
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335
You should only ever need dabs of RTV on a cam cover at corners or transition points (i.e. timing cover to head mating), YMMV depending on what car your working with (beyond N54). Torquing again is highly recommended - these are low torque applications, and over rubber it's looking to compress, move around, and lose torque on the head. With modern cars I think it is exceptionally wise to own a good quality 1/4" torque wrench. I use the Wera 1/4" torque wrench and recommend it.

Filippo
That wera unit looks good. I bought a bunch of wera, nipex, and some other euro brand quality tools for here at work. So far, I've yet to be disappointed in them.
 

fmorelli

Major General
Staff member
Aug 11, 2017
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Knipex is very good. I had a german hand tool business at one point - sold Stahlwille. There are lots of German hand tool manufacturers ... more stuff in Europe that isn't typically imported, though the Internet has changed that. One trick is to order from Europe Amazons ... :)

Filippo
 
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fmorelli

Major General
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That wera unit looks good. I bought a bunch of wera, nipex, and some other euro brand quality tools for here at work. So far, I've yet to be disappointed in them.
Somewhere we need to start a tool thread to share favorites.

This thread is about spent so I don't mind making another comment, since you mentioned Knipex, that their electrical snips are the bomb. I get tired of wearing out electrical snipes ... mostly because the moment the jaws quite don't align or the edge gets marred (Rockwell hardness too low) I nurse them along when I should chuck them. Got sick of that and spent real money on the Knipex electric super knips along with the baby 75 15 110 diagonal cutters. They are electromagnetically induction hardened.

That said I'd like to get some TDI International tools - American made and I like what I see!

Filippo
 

NoQuarter

Major
Nov 24, 2017
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Indiana, USA
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Z4 35is, 535xi, X5 35i
I like to use a gasket "dressing".
Somewhere we need to start a tool thread to share favorites.

Filippo

I totally support the idea of a tools thread!

Filippo, you always take the time to share a tool that you have used and can recommend, I think you should be the OP and start us off a new thread!
 
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veer90

Lieutenant
Nov 16, 2016
1,000
763
25
West Nyack, NY
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e90 335i 6MT
not supposed to use RTV or any type of sealant AFAIK. Just make sure the mating surface is clean, dry, and torque all bolts to spec starting from the middle and working outward in a star pattern.
 

NoQuarter

Major
Nov 24, 2017
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Indiana, USA
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Very similar but
Specifically this product is what I have now:
41TQEBGOaXL._SL500_SS75_SS75_.jpg

Hylomar Advanced Formulation (3 oz. Tube)
by Silver Seal
Link: http://a.co/5RIPD9E
 

matreyia

Major
Apr 19, 2017
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690
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335i e93
I tightened mine a little, let it setovernight, then final torqued in the morning. No gasket maker used. Will check again for leaks soon and retorque if needed.

Used ATF grease inside grooves to hold gasket in place. When heated the grease melts away and leaves no harmful effects. Totally inert blue grease.
 
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1and1

Specialist
Dec 28, 2016
60
34
0
Tally, FL
Worth it to let it heat cycle a few times before retorque I think.... I did a week's worth of daily driving & commuting to the office etc. By the next weekend she was starting to seep, and was desperate to be torqued again.

It's been months since, and she remains dry and clean.
 
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matreyia

Major
Apr 19, 2017
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Worth it to let it heat cycle a few times before retorque I think.... I did a week's worth of daily driving & commuting to the office etc. By the next weekend she was starting to seep, and was desperate to be torqued again.

It's been months since, and she remains dry and clean.


Weird, I have done 4 valve cover jobs for different e93 and e92 cars and never had to retorque...zero leaks. HOWEVER, I followed the torque pattern instructions EXACTLY as stated in the Bentley Manual. I never just torque from center outwards as many people on many forums have advised.

Knock on wood that Bentley does not fail me.
 
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N54QC

Corporal
Aug 17, 2017
127
67
0
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07 E90 335i
Weird, I have done 4 valve cover jobs for different e93 and e92 cars and never had to retorque...zero leaks. HOWEVER, I followed the torque pattern instructions EXACTLY as stated in the Bentley Manual. I never just torque from center outwards as many people on many forums have advised.

Knock on wood that Bentley does not fail me.
Same here, followed the manual and had zero issues.
 

NoQuarter

Major
Nov 24, 2017
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I think it is also safe to say, with these cars going through multiple owners and previous valve cover gaskets, one can't always rely on the surface not to have been scratched up due to some over-aggressive prying and scraping.
 

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Corporal
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Jun 4, 2018
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You should not have to go back and re-torque the valve cover fasteners. The bolts have a built in large diameter flange that push down the valve cover which then compresses the rubber valve cover gasket. The same flange on the bolt bottoms out on a metal sleeve in the holes of the valve cover. The metal sleeve is actually taller than the height of the valve cover. This ensures the exact proper compression of the rubber gasket, IE you can't over compress the gasket. As with any bolt, torque is created by the bolt stretch from bottoming out on the metal sleeve. In theory, they should not come un-torqued from the heat-cycling of the gasket and/or plastic valve cover.

As @fmorelli said, having a good quality torque wrench is key with this. These are tiny fasteners with a low torque spec. 8.5 Nm (~45 in/lbs). I cheat a little and usually go 10 Nm. Its also important to note that cleanliness is key. It is a good idea to clean the bolts AND clean out the bolt holes in the head before re-installing the bolts. A touch of brake clean in the holes and blow them out with an air gun is what I do. On a street car I roll with it as is but on a race car I put loctite 243 (243 cures in the presence of oil) on the bolts.

People say these bolts should be replaced but BMW does not require it. They are steel and NOT a stretch bolt therefore no need to replace.

TIS says torque in a crosswise pattern going from inside to outside. (like a cylinder head to block) I don't have a Bentley so not sure what it says.
 

matreyia

Major
Apr 19, 2017
1,751
690
0
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335i e93
You should not have to go back and re-torque the valve cover fasteners. The bolts have a built in large diameter flange that push down the valve cover which then compresses the rubber valve cover gasket. The same flange on the bolt bottoms out on a metal sleeve in the holes of the valve cover. The metal sleeve is actually taller than the height of the valve cover. This ensures the exact proper compression of the rubber gasket, IE you can't over compress the gasket. As with any bolt, torque is created by the bolt stretch from bottoming out on the metal sleeve. In theory, they should not come un-torqued from the heat-cycling of the gasket and/or plastic valve cover.

As @fmorelli said, having a good quality torque wrench is key with this. These are tiny fasteners with a low torque spec. 8.5 Nm (~45 in/lbs). I cheat a little and usually go 10 Nm. Its also important to note that cleanliness is key. It is a good idea to clean the bolts AND clean out the bolt holes in the head before re-installing the bolts. A touch of brake clean in the holes and blow them out with an air gun is what I do. On a street car I roll with it as is but on a race car I put loctite 243 (243 cures in the presence of oil) on the bolts.

People say these bolts should be replaced but BMW does not require it. They are steel and NOT a stretch bolt therefore no need to replace.

TIS says torque in a crosswise pattern going from inside to outside. (like a cylinder head to block) I don't have a Bentley so not sure what it says.

Bentley manual has a bizarre pattern of tightening. Not really in to out at all. Very specific pattern.