Why are valve covers leaking out bolt holes?

[pickupman]

Just redid valve cover gaskets because after last time I did them, they started leaking even worse than they had been leaking, and it seems that the leaks were all originating from around the bolt holes.

This time, I checked that the surface was flush along the valve covers and discovered that some of the areas near the bolt holes was not flush as if I had over-tightened them. Anyways, I straightened all the uneven areas out and even took a dremel tool to smooth out a few jagged edges near the bolt holes. When installing the gasket, I used RTV on the valve cover side of the gasket (I hadn't done this previous and wanted to see if it would help).

I reversed the load spreaders, tightened all the bolts down hand-tight, and then torqued the bolts about a half turn more starting on from the center and working to the bolts on the outside.

After going out for a test drive, the problem is exactly the same. There is oil coming out from the bolt holes. I'm not sure why this keeps happening. It's getting frustrating.

 

[MTKirk]

Just redid valve cover gaskets because after last time I did them, they started leaking even worse than they had been leaking, and it seems that the leaks were all originating from around the bolt holes.

This time, I checked that the surface was flush along the valve covers and discovered that some of the areas near the bolt holes was not flush as if I had over-tightened them. Anyways, I straightened all the uneven areas out and even took a dremel tool to smooth out a few jagged edges near the bolt holes. When installing the gasket, I used RTV on the valve cover side of the gasket (I hadn't done this previous and wanted to see if it would help).

I reversed the load spreaders, tightened all the bolts down hand-tight, and then torqued the bolts about a half turn more starting on from the center and working to the bolts on the outside.

After going out for a test drive, the problem is exactly the same. There is oil coming out from the bolt holes. I'm not sure why this keeps happening. It's getting frustrating.

Maybe get new bolts? If you decide to take the covers off again, just before you put in the bolts squirt some ultra-black rtv in the bolt holes, then tighten the bolts just past finger tight, then let the rtv cure overnight before final tightening of the bolts. This keeps you from deforming the valve covers, and helps seal deformed covers.

 

[riotwarrior]

Just redid valve cover gaskets because after last time I did them, they started leaking even worse than they had been leaking, and it seems that the leaks were all originating from around the bolt holes.

This time, I checked that the surface was flush along the valve covers and discovered that some of the areas near the bolt holes was not flush as if I had over-tightened them. Anyways, I straightened all the uneven areas out and even took a dremel tool to smooth out a few jagged edges near the bolt holes. When installing the gasket, I used RTV on the valve cover side of the gasket (I hadn't done this previous and wanted to see if it would help).

I reversed the load spreaders, tightened all the bolts down hand-tight, and then torqued the bolts about a half turn more starting on from the center and working to the bolts on the outside.

After going out for a test drive, the problem is exactly the same. There is oil coming out from the bolt holes. I'm not sure why this keeps happening. It's getting frustrating.

Maybe get new bolts? If you decide to take the covers off again, just before you put in the bolts squirt some ultra-black rtv in the bolt holes, then tighten the bolts just past finger tight, then let the rtv cure overnight before final tightening of the bolts. This keeps you from deforming the valve covers, and helps seal deformed covers.

First what was the GASKET made of?

Second did you clean bolt threads and bolt hole threads equivalemt of SURGICALLY clean? I MEAN EXCEEDINGLY SURGICALLY CLEAN?

Thirdly what torque did you tighten bolts too?

Fourthly what brand and type of RTV did you use?

Fifthly why did you utilize RTV with a Gasket?

I am all for RTV a d all for gaskets however I may be NOT inclined to use both together.

Answer the above then maybe ther can be answers....I tend to be super duper **** about how freakishly surgically clean ***** must be to seal

But *** do I know?

JM7.3CW

 

[pickupman]

First what was the GASKET made of?

Second did you clean bolt threads and bolt hole threads equivalemt of SURGICALLY clean? I MEAN EXCEEDINGLY SURGICALLY CLEAN?

The gasket is just a normal felpro rubber gasket. I used brake clean on everything. I cleaned off everything on both the valve covers and head including the bolts and spreaders.

Thirdly what torque did you tighten bolts too?

I tried to get everything to around ~5in-lbs, but some of it's guess work because I can't get the torque wrench to fit in some of the spaces where all the bolts are. That it why I say that I hand tighten them and then go a little bit past that. It's what ends up being about 5in-lbs or so.

Fourthly what brand and type of RTV did you use?

Fifthly why did you utilize RTV with a Gasket?

I am all for RTV a d all for gaskets however I may be NOT inclined to use both together.

Answer the above then maybe ther can be answers....I tend to be super duper **** about how freakishly surgically clean ***** must be to seal

But *** do I know?

I used permatex high temp copper RTV. I did that because this is the third time trying to get these valve covers to seal. First time I installed the gaskets dry. They just leaked everywhere. Second time, I used a gasket adhesive to make sure the gasket was saying seated. They leaked less, but mainly coming from the bolt holes. I literally spent a full day cleaning the valve covers and everything before I put the new gaskets in. I've done valve covers gaskets on other vehicles and never had any problems whatsoever with leaks. These I just can't seem to get the leaks to stop.

 

[riotwarrior]

The gasket is just a normal felpro rubber gasket. I used brake clean on everything. I cleaned off everything on both the valve covers and head including the bolts and spreaders.



I tried to get everything to around ~5in-lbs, but some of it's guess work because I can't get the torque wrench to fit in some of the spaces where all the bolts are.



I used permatex high temp copper RTV. I did that because this is the third time trying to get these valve covers to seal. First time I installed the gaskets dry. They just leaked everywhere. Second time, I used a gasket adhesive to make sure the gasket was saying seated. They leaked less, but mainly coming from the bolt holes. I literally spent a full day cleaning the valve covers and everything before I put the new gaskets in. I've done valve covers gaskets on other vehicles and never had any problems whatsoever with leaks. These I just can't seem to get the leaks to stop.

Ok sounds **** nasty...

Bolt holes cleaned...recleaned...and recleaned w brakeclean...??? Use aire to get schmeg out between cleanings...clean until no can clean no more white paper towel zhows clean brake lean pouring from holes.

Clean bolts....wire wheel them beachtez....clean w brake clean...che k w paper towel

Head and VC gasket surface...same....must be clean enough new born daughter can lick all fay long

2 options.....VC gasket ...or no VC gasket..your choice!

No VC Gasket

1/8 - 3/16" bead RTV your choice is good BTW....on head surface.....one bead inside bolt holes....close up bolt holez after...set VC in place...insert boltz slowly tigten...do not fully tighten....wiggle VC all about...let RTV SET 24HRS....now tighten to full torque.....JM7.3CW

VC gasket

Take elephant snot apply to head surface and VC directly place gasket in place and ensure some snot in bolt holes too tighten to torque.

Let set 24hrs

Run engine

Both methods should provide same resjltz...elephant snot uzually works best with cork not rubber gaskets....

IMHO

JM7.3CW

or thread sealant on bolts...but thats nasty.....oil tollerant locktite blue would be good choice...

 

[MTKirk]

Ok sounds **** nasty...

Bolt holes cleaned...recleaned...and recleaned w brakeclean...??? Use aire to get schmeg out between cleanings...clean until no can clean no more white paper towel zhows clean brake lean pouring from holes.

Clean bolts....wire wheel them beachtez....clean w brake clean...che k w paper towel

Head and VC gasket surface...same....must be clean enough new born daughter can lick all fay long

2 options.....VC gasket ...or no VC gasket..your choice!

No VC Gasket

1/8 - 3/16" bead RTV your choice is good BTW....on head surface.....one bead inside bolt holes....close up bolt holez after...set VC in place...insert boltz slowly tigten...do not fully tighten....wiggle VC all about...let RTV SET 24HRS....now tighten to full torque.....JM7.3CW

VC gasket

Take elephant snot apply to head surface and VC directly place gasket in place and ensure some snot in bolt holes too tighten to torque.

Let set 24hrs

Run engine

Both methods should provide same resjltz...elephant snot uzually works best with cork not rubber gaskets....

IMHO

JM7.3CW

or thread sealant on bolts...but thats nasty.....oil tollerant locktite blue would be good choice...

I agree, and would prefer the all RTV route. It is best not to mix rtv with other gaskets, it seems to make a weak spot for a leak. BUT! I have had success in bolt holes of gaskets, the key is to make sure it stays only in the bolt hole, and doesn't ooze onto the gasket sealing surface. Benz diesels are notorious for leaking through the bolt holes, so most people use RTV there along with the rubber gasket, you could use rtv all the way around but, clean-up is harder and the covers must come off every 12,000 miles for valve adjustment. RTV is much easier to clean-up next time than the Elephant snot (assuming you mean aviation form-a-gasket). I believe the main reason engines use so many gaskets and not just rtv, is the cure time. You have to wait for it to cure before you tighten it all the way or it all just oozes inside your engine. Mechanics would go broke if they had to wait for RTV to cure.

 

[f-two-fiddy]

Use a cork gasket with RTV on both sides. I've never had a leaker doing this.

 

[no mufflers]

mine started to do this a little while ago. it was only on a few of the bolts. I just took out the leaky bolts cleaned them and put rtv on threads and the washer and have had no leaks.

 

[jwalterus]

Use a cork gasket with RTV on both sides. I've never had a leaker doing this.

IMHO, if it's cork, it gets indian head shellac, period.

 

[riotwarrior]

IMHO, if it's cork, it gets indian head shellac, period.

Thats where ai prefer elephant snot...aka aviation form a gasket...not dissing shellac..never used it is all.

 

[icanfixall]

Really sounds like some other problem is causing these leaks. Might be bad crankcase venting so it builds pressure and blows oil out past the threads because this is the weak link.
I have never had issues using the copper plus permatex on the felpro gaskets. I do not recall if I used rtv on the valve cover bolts. I would think if rtv was used in the valve cover gasket bolt holes then no oil could possibly leak up past then. Kind of guessing here..

 

[riotwarrior]

Great point @icanfixall as high crank case pressure will indeed force oil out all over.

Nothing will hold then

 

[no mufflers]

I do have a RDT so I do think that is a contributing factor to some odd small leaks that accrue over time.

 

[pickupman]

Checked the CDR and I can blow through it so it doesn't seem clogged or anything. Any way to determine if there would be anything causing high crankcase pressure?

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[f-two-fiddy]

IMHO, if it's cork, it gets indian head shellac, period.

Yeah, the only reason I say RTV to the valve cover gasket is for ease of removal. Seeing as how you will eventually have the cover off.

Otherwise I have to agree. Indian Head and Cork will seal for years, and years, and.....