Cylinder head gasket oil leak

[worthydolt]

Dear All,

I have a bit of a persistent oil weep from the left hand cylinder head gasket of my 96 R1100.

I've replaced both head gaskets with the new 3-layer ones and the RHS is nice and dry now.

Steptoe's sticky on this job was my guiding light. Thanks man!

The LHS was leaking immediately after I replaced the gasket and, I think, from a different place than before I replaced it. Although I'm not topping up the oil any more than I was before, it's more a weep than p*ssing out.

So, last weekend I pulled off the head again and gave everything a look over checking for casting imperfections and cracks. I couldn't see any.

I then laid a spirit level both on the head and on the face of the cylinder. It all seems nice and flat.

So I put it all back together and bolted it all down as per the BMW manual. 20Nm then 90deg then 90deg on the four nuts, then the 40Nm stud, then the little stud near the cam sprocket.

I've pretty well run out of ideas now. If anybody can see anything I haven't thought of (BTW I've also replaced the doughnut washer around the spark plug) I'd be really grateful.

If not, I'm looking for recommendations for a good garage who I can hand the problem over to. I'm near York.

Cheers,
Neil

 

[pomm001]

Dear All,

I have a bit of a persistent oil weep from the left hand cylinder head gasket of my 96 R1100.

I've replaced both head gaskets with the new 3-layer ones and the RHS is nice and dry now.

Steptoe's sticky on this job was my guiding light. Thanks man!

The LHS was leaking immediately after I replaced the gasket and, I think, from a different place than before I replaced it. Although I'm not topping up the oil any more than I was before, it's more a weep than p*ssing out.

So, last weekend I pulled off the head again and gave everything a look over checking for casting imperfections and cracks. I couldn't see any.

I then laid a spirit level both on the head and on the face of the cylinder. It all seems nice and flat.

So I put it all back together and bolted it all down as per the BMW manual. 20Nm then 90deg then 90deg on the four nuts, then the 40Nm stud, then the little stud near the cam sprocket.

I've pretty well run out of ideas now. If anybody can see anything I haven't thought of (BTW I've also replaced the doughnut washer around the spark plug) I'd be really grateful.

If not, I'm looking for recommendations for a good garage who I can hand the problem over to. I'm near York.

Cheers,
Neil

Considering the bike is a few years old its a fair bet that the heads have been off a couple of times before, I would check that the bolts/studs have not been stretched , if they are you will not get the load into the joint.get some new ones.
Also confirm if the new style of head gasket can be used on your engine with the orinial fixings
Other than that if there is no damage to the surfaces it should seal OK, make sure there are no scratch marks agross where the gasket bead sits

 

[worthydolt]

Thanks. The cylinder studs are something I hadn't thought of.

I know the history of the bike. I bought it with 7k on the clock from a friend who bought it new. So I know the heads have only been off twice.

Roughly how many times will those studs stand being loosened and tightened?

If I were to replace them, how in God's name do you go on about getting them out of the cylinder? Mole grips and swearing?

Cheers

 

[spot]

Did you replace the head gaskets each time? I think they need replacing every time the head comes off. The mating surfaces should be extremely clean aswell. As for getting studs out its easy. thread two nuts on , tighten them up against each other and wind the stud out! cant see it being stretched studs though.

 

[ebbo]

The only way I know of to be sure a surface is truly flat is to grind it with fine grinding paste on a piece of glass, wipe clean and check for even grinding marks.

That got a Tiger Cub dry, that leaked like the Torrey Canyon