Cometic oil leak before engine run

kokkolanpoika · Post by **kokkolanpoika** » Fri Aug 05, 2016 6:34 pm

Hi.

I do not know what to do. I just rebuild my 5.2L Rover V8. I bought some cometic 96mm head gasket and just fit those.
So i fit rocker shaft´s etc, spill some 15w50 Castrol motor oil with rockers, let car stand couple of days. Today i go to underneath car and i notice some oil drip with head/block mounting face. Precise head gasket rivet, witch is outside block face. It will look like gasket is leaking inside between layers, not block or head gasket surface. Because gasket will look dry top/bottom side.

So are those gasket´s totally grap, or is my gasket leaking oil at the walley outside engine before i start my engine. It will take couple of week before i can try to start it. I have to modify exhaust manifold and pipe..

I do not have any coolant on my engine, and i´m scared it will leek oil pressure and coolant outside when it will run..

Im running serpetine timing cover, so i do not have any oil pressure on the engine.

Surfaces are clean and straight and our machine shop says that they are smooth enought to MLS gasket.

I´m using ARP studs, torque settings 95Nm.

I still wonder how to he...ll they can leak oil before engine run, and they look like leak both same place.. 6/8 and 5/7 cylinder

ratwing · Post by **ratwing** » Fri Aug 26, 2016 6:59 pm

Any luck fixing this?
When I had something similar someone said maybe the dowels to locate the heads are too high so the heads won't bolt down?
Are you sure all the bolts were done up tight and to the right torque?
I only mention this because when I checked mine, most were loose (although this was with composite gaskets). I was sure I'd done them all up to the correct torque but wonder if I'd set the wrong number on the torque wrench by mistake?

kokkolanpoika · Post by **kokkolanpoika** » Sun Aug 28, 2016 7:38 am

If all go okay, today i will try to start engine, and drive my cam in. At least tomorrow.

I have to only buy more fuel, add coolant and fit lamda sensor´s. And check all are okay.. + fit mechanical oil pressure gauge to make sure pressure is ok.

And those gasket´s are still slightly leaking..

I only check outer bolt´s of head, and notice that they are slightly loose, they will go approx 5-10Nm when i re torque them, without loosening them.

Dowels are ok..

kokkolanpoika · Post by **kokkolanpoika** » Sun Aug 28, 2016 3:17 pm

She´s running again..

Look like leak will worse after startup, but when she get hot, it will become steady, and look like it will leak very small amount anymore.. Tomorrow i will make new cold startup and let it cool and near futrure i will retorque stud´s and hope for best.. Coolant and oil pressure stays where they should..

kokkolanpoika · Post by **kokkolanpoika** » Wed Aug 31, 2016 8:09 pm

Just made an re torque today.

All nut´s go approx 30degree. I mark all nut´s with white pencil.
I opened them half turn, and then re torque again.

I have to adjust valve clearance again, and maybe next week i can try to restart engine and hope for best.. Weekend is busy..

Also i made an quick calculations.. if studs are 7/16UNF then 30deg turn will make 0.1mm more compression for gasket..

kokkolanpoika · Post by **kokkolanpoika** » Wed Sep 07, 2016 7:07 pm

Now it will leak only when it is started and it will warm up.. About 40-50C leak start´s and after approx 70C leak is near zero..

Normal running temperature 80-90c and oil approx 70C, it wont leak anymore..

Damn, i don´t get it..

Is my Top hat liner over the block deck?
Mounting face smooth enought? Before i build bottom end i will clean it wet 1000 sandpaper..

Now it will leak just there where is block number and another side between 6/8 cylinder..

Do i have to change composite gaskets? Or take cometic´s off and add some sealant?

Or make couple of gold start, and hope for best?

Help please..

jenko · Post by **jenko** » Thu Sep 15, 2016 11:14 am

Have you explored ratwing's suggestion....If the dowels are too high, no amount of torque will help....This would make sense. as there is no way anything should leak with no pressure.

kokkolanpoika · Post by **kokkolanpoika** » Wed Sep 21, 2016 12:44 pm

Dowels are not to high. I have measured those and tested head´s in place without gasket.

Here is similar issue like mine..

http://www.v8forum.co.uk/forum/viewtopi ... b667b93266

DEVONMAN · Post by **DEVONMAN** » Wed Sep 21, 2016 2:45 pm

You could try plugging the redundant hole at the rear of the heads under the rocked shaft post.
This my solve or at least reduce the leak.

kokkolanpoika · Post by **kokkolanpoika** » Wed Sep 21, 2016 6:56 pm

I have got shim´s under pedestals and only front of the head has got oil hole.. Of course bolt hole might leak slightly..