EDIT: Problem solved - see near bottom.

Oil leaks, especially valve cover leaks are a very old on-going problem for everyone with a Duke (or SD4) engine. Not sure why it seems SO impossible a job to seal a Duke engine using standard practices that work fine on every other engine I've ever worked on.

I'm finding oil leaking in the circled area above (not a pic of my engine) and puddling in the the spark plug holes. The only bolt holes in that area are the 2 that bolt the valve cover down and the 2 empty threaded bolt holes that are visible.



On my SD4 aluminum head, I have the aluminum Edelbrock valve cover and had used the Felpro PN FEL-VS50179T originally. This rubber/steel gasket has raised edges to seal and comes with all the hardware needed for installation. Got leaks. Maybe from under/over torquing?? Bolts come loose over time??



Then I decided to "glue" the damn valve cover down using Permatex "The Right Stuff". Still leaked.



I've pulled the valve cover off and don't see an obvious break where it could have leaked from the bead I laid down.



AND I kept the bead "inboard" of the valve cover bolts as the Service Manual instructs. Is oil pushing up through the valve cover bolts there?? What about the 2 holes that are visible? They appear to bottom out, not into any oil gallery.

The filler "neck" on the SD4 valve cover was also installed with Right Stuff and it doesn't appear that oil is leaking from there, or being pushed up through the filler cap. The top cover has a new gasket as well!!

I'm stumped!! Any ideas??

------------------


World of Wheels Winners
My 3.4L S/C 87 GT
& Super Duty 4 Indy

[This message has been edited by fierosound (edited 07-10-2010).]

Not the right stuff ! CLEAN the head & the cover, put about 1/8" bead of PERMATEX COPPER GASKET MAKER on Both the Head AND the Cover, with a Clean gasket in between, bolt it down, let it dry overnight. unless your valve cover is Cracked, it'll never leak again.

I don't have any leaks, and I just used black RTV on both sides of the flat rubber valve cover gasket.

I spent some time making the flange on the valve cover flat.

I also torqued the valve cover bolts in two steps. I put the RTV on, let it tack/start to get firm, flopped the valve cover on, and put the bolts in finger-tight. The next morning I gave them a few ft-lbs.

Also, if you have pressure in your crankcase (like a bad PCV or no PCV problem) you will blow gaskets out very consistently.

Man alive, that's exactly where my cover was leaking from too, matter of fact on both Dukes.

Probably redundant information to you but I did thoroughly clean the cover and especially the lip and surrounding area on the head as perfectly as I could. Absolutely zero old gasket material and brake cleaner on everything so it was perfect and I do mean perfect but you nad everyone already knows that stuff.

For what it's worth, I did raise the front end of the cars about 5 inches and didn't start or drive the cars for a full day afterwards. I did use the "Right Stuff" too, applied it to the metal surfaces and gave it an extra shot around the outside of the bolt holes, standard cork gasket. I tightened from the center bolt in a star pattern out to the ends just a little at a time and repeated the process several times. I don't have a torque wrench that goes down that low so I was indead guessing but stopped right at the point of increasing resistance, using not a wrench but a small nut driver.

Those darn leaks were getting me so frustrated I was about to launch a wrench into orbit, or through a wall. Anyways, that's how i did mine, hope you have some good luck as you tackle this again

Maybe the head is warped?????

The pan lip might be bent if it is try straiting it out with a soft hammer. Make sure the bolts are torqued down to spec a cork gasket is a must on the duke VC. Use 3M weatherstripping adhesive (yellow or black). on the gasket and bolts

Mine is all stock, but i used a $14 dollar black rubber gasket, torqued to spec and am still good to go 2 years later.
If you must, high temp silicone works wonders.

get some valve cover bolt spreaders... they are like long washers that help spread the load of the bolt. I also used studs in the head with nuts and locking washers. For the studs I used loctite to hold them in place.

To flatten the valve cover, don't use a hammer, use a couple pieces of wood and pound on them with a hammer. This will keep the small dents to a min.

I haved tried cork only gaskets and they suck. I have tried the "right stuff" and that stuff leaked. I did it all. I wanted NO leaks, but the only way I could get it was to replace the valve cover with a new one, use high-tack sealant from permatex and a cork gasket with a steel center. Oh... and those bolt spreaders (they make them for V8 engines).

J.

The blue FelPro gasket pictured above is not supposed to be used with any type of sealant, and both surfaces (head and cover) must be clean and oil free when it is installed. If it is installed correctly and torqued correctly, it will not leak. If you get a leak, something must be wrong with the head or cover.

quote Originally posted by TopNotch: ...something must be wrong with the head or cover.

I am sure we'd have noticed something when we cleaned it up. Oil leak in this area.




The Edelbrock valve cover didn't appear to have anything wrong as it came new out of the box.
It's a heavy alumimum cover, not a stamped "tin can" type.




What do the head bolts go into?? Coolant or oil passages?? Either way, I'm sure we applied sealant to the ones that required it.

------------------


World of Wheels Winners
My 3.4L S/C 87 GT
& Super Duty 4 Indy

[This message has been edited by fierosound (edited 10-14-2009).]

OH... that cover. They I would think the blue gasket would work... hmmm
maybe RTV would work for this cover. RTV doesn't work well with the stamped cover, I found.

J.

Sweeet!
Maybe you can RTV from the inside?

------------------
84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

quote Originally posted by jaskispyder: ... get some valve cover bolt spreaders... they are like long washers that help spread the load of the bolt. ... use high-tack sealant from permatex and a cork gasket with a steel center.

The Felpro PN FEL-VS50179T comes with them, and have used them each time.
I really thought this would be the "perfect gasket" for the Edelbrock cover.
What's the PN for the "cork gasket with a steel center"?




Looked through my boxes of stuff. Found a Fel-Pro PN1621 valve cover cork gasket.

Directions:
1. Clean cover gasket surface free of foreign particles. Wipe off excess oil with a degreasing agent.
2. Straighten the cover flanges. Distorted covers should be replaced.
3. CEMENT gasket to cover using a good quick-drying adhesive.
Sparingly apply the adhesive, allowing 1-2 minutes of setting time prior to gasket installation.
4. Install cover onto engine; avoid over-torquing. Whenever possible, use load spreader washers under bolt heads.

Guess I could try this, and if I cross my fingers and hold my mouth right - it might work??

[This message has been edited by fierosound (edited 10-14-2009).]

quote Originally posted by 2.5: ...black rubber gasket...

Gee, 2 Fiero owners agreeing. That's a pretty strong consensus in this hobby, lol.

quote Originally posted by fierosound: The Felpro PN FEL-VS50179T comes with them, and have used them each time. I really thought this would be the "perfect gasket" for the Edelbrock cover. What's the PN for the "cork gasket with a steel center"?

If you're referring to the Super Duty valve cover -- I have one on my duke, and it doesn't leak (with the blue FelPro gasket). You don't use the spreaders with this cover, but you do need longer than stock bolts to hold it on, because of it's thickness.

I think I figured it out. I had the bead of sealant inboard of the bolt holes as per the manual.

But with the Edelbrock valve cover, the bolts are INSIDE the valve cover,
so oil was travelling through the bolt holes from the inside to the outside. DOH!!



Just need to put the bead of sealer completely around all the bolt holes on the head.

That still doesn't explain why it leaked using the blue silicone gasket. Those seal all around the bolt holes.

[This message has been edited by fierosound (edited 07-11-2010).]

Felpro Part # are:

VS50179T - Above Kit
VS50179C - Cork
VS50179R - Rubber
Cork/rubber comes with EGR gasket only.
Most auto part store has cork and/or rubber. Special order VS50179T kit approximate $30-$32.

Never use RTV silicon with gasket!
Use High Tact, Super300, (Both Permatex) or Balkamp Aviation sealer on cork or rubber.
Silicone gasket usually go dry. PermaDryPlus in VS50179T I expect it goes dry...

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top of every forum page...)

[This message has been edited by theogre (edited 10-15-2009).]

I decided to use sealer again instead of a gasket. With the removable top, the cover NEVER needs to come off again except for major head work. As I mentioned, with the Edelbrock valve cover, the bolts are INSIDE so oil was basically going through the bolt hole. I made sure to put a bead of sealer COMPLETELY around each bolt hole, and a bit on each bolt as well to help prevent the bolts from backing out. Finally, NO leaks!!

I also had my polished aluminum parts chrome plated for more "bling".

[This message has been edited by fierosound (edited 01-21-2010).]

<bump>

quote Originally posted by fierosound: I decided to use sealer again instead of a gasket. With the removable top, the cover NEVER needs to come off again except for major head work. As I mentioned, with the Edelbrock valve cover, the bolts are INSIDE so oil was basically going through the bolt hole. I made sure to put a bead of sealer COMPLETELY around each bolt hole, and a bit on each bolt as well to help prevent the bolts from backing out. Finally, NO leaks!! I also had my polished aluminum parts chrome plated for more "bling".

Wow! That's sweet!

------------------

..Looking good .I like engine bay very much.slight envious drool..

with damaged covers the spreaders work very good

...I have salvaged damaged Valve covers by glueing a few pieces of 600/400 grit wet sand paper to card board to resurface

Thanks guys