For some reason, I want r3v's opinion on this HG leak

[acolella76]

So ever since I did my head swap the HG has been leaking a bit of oil on the exhaust side. Not a lot to the point where it's constantly low on oil, but enough for it to leave a golfball size puddle whenever I park and it pisses me off.

Some things to know: both surfaces are clean enough to eat off of. MLS cometic gasket. The head bolts weren't torqued enough because after I torqued them I found out that my torque wrench read 5lbs more than it really was >< so I replaced the head bolts and torqued them all down properly and they're up to spec. Compression numbers on all the cylinders were even.. about 155 for all cylinders.

This is where it's leaking and how much it's leaking:
*the VC is not leaking

[Vtec?lol]

once you compress the gasket enough to seal and then remove the bolts, that seal is permanently broken.

[acolella76]

once you compress the gasket enough to seal and then remove the bolts, that seal is permanently broken.

what? it is an MLS gasket, it is reusable.

[Vtec?lol]

^didn't get that part

[acolella76]

In the paragraph in the first post ;) lol all I really want to know is if you guys think it's acceptable and boost-able or if I should fix it.

[Vtec?lol]

Ditto, my bad lol.

Time to re-clean everything and re-torque

[acolella76]

both surfaces were completely straight and i'm on my 2nd set of new head bolts :/

[jlevie]

In the picture it looks like there is oil on the head above where the head meets the block. That implies that the oil might be coming from the valve cover. Clean the engine of all oil then watch for the first sign of seepage to find the source.

[slammin.e28]

Half moons.

[sweet6e30]

In my experience with MLS Cometic gaskets, especially on Sr and Rb engines that i have built. they seem to sweat eventually. They are reusable, I recommend spraying permatex copper gasket spray between the layers and and on both mating surfaces of the gasket, we've had great success with this. Make sure the head surface is straight and CLEAN, the same with the BLOCK.

or you can opt for a Cosworth gasket, which are amazing.

Sometimes OEM is better, if your not boosted, OEM




check your rocker shaft plugs, you can throw a bit of rtv (right stuff) on them to give a good seal on the head

check your valve cover gasket, put a new one and make sure it is seated properly and tightened down,

check your breather hose coming off the valve cover also

hope that helps, good luck

[LJ851]

Explain your methods for measuring the flatness of the head and block.Did it leak before you retorqued? Just because the gasket is reusable doesn't mean that you can install it covered in oil and coolant which is what happened when you retorqued. Also MLS head gasket is very sensitive to the surface finish of the parts compressing it. I will second sweet6e30's suggestion of a light coat of permatex copper gasket spray (on perfectly dry, flat surfaces)
Lorin

[acolella76]

In the picture it looks like there is oil on the head above where the head meets the block. That implies that the oil might be coming from the valve cover. Clean the engine of all oil then watch for the first sign of seepage to find the source.

Cmon jim, read the sentence above the picture :p

Half moons.

What?

In my experience with MLS Cometic gaskets, especially on Sr and Rb engines that i have built. they seem to sweat eventually. They are reusable, I recommend spraying permatex copper gasket spray between the layers and and on both mating surfaces of the gasket, we've had great success with this. Make sure the head surface is straight and CLEAN, the same with the BLOCK.

or you can opt for a Cosworth gasket, which are amazing.

Sometimes OEM is better, if your not boosted, OEM




check your rocker shaft plugs, you can throw a bit of rtv (right stuff) on them to give a good seal on the head

check your valve cover gasket, put a new one and make sure it is seated properly and tightened down,

check your breather hose coming off the valve cover also

hope that helps, good luck

Literally everything on the head is brand new, including the plugs, VC gasket is not leaking, breather hose is vented to atmosphere. I asked Cometic if they thought I should be running a copper spray of some sort and they said I should run the gasket as is.

Explain your methods for measuring the flatness of the head and block.Did it leak before you retorqued? Just because the gasket is reusable doesn't mean that you can install it covered in oil and coolant which is what happened when you retorqued. Also MLS head gasket is very sensitive to the surface finish of the parts compressing it. I will second sweet6e30's suggestion of a light coat of permatex copper gasket spray (on perfectly dry, flat surfaces)
Lorin

Measured with a straight edge and a feeler gauge, just like the Bentley manual says to do. The surface was 100% straight which doesn't surprise me, it's a cast iron block it's hard to warp. I also cleaned the surface so well I could have eaten off of it. It did leak before I retorqued it, in more than one spot. Since I've retorqued it this is the only spot that's still seeping a little bit.

[AnimalE30]

Every mls headgasket turbo build I've seen they've used a Cooper spray between the layers. A lot of people on bimmer forums couldn't get them to seal properly and opted for o-ringing the block with a stock head gasket.

I think you would have better luck with a stock head gasket and metric blues or arps.

[acolella76]

Every mls headgasket turbo build I've seen they've used a Cooper spray between the layers. A lot of people on bimmer forums couldn't get them to seal properly and opted for o-ringing the block with a stock head gasket.

I think you would have better luck with a stock head gasket and metric blues or arps.

Yeah its weird. Cometic and a few people who sell Cometic gaskets recommend no spray, forums recommend spray. Oh well..

[jlevie]

Cmon jim, read the sentence above the picture :p

I read that, but the fact remains that there is oil above the head gasket. Liquids don't run uphill. While it is possible that airflow through the engine compartment is blowing the oil upwards, the simpler explanation is that the valve cover gasket or the rubber bungs are leaking. Throughly cleaning the engine and watching for the first sign of oil will settle that question once and for all. Or, add UV dye to the oul and watch for the leak with a UV light.

Measured with a straight edge and a feeler gauge, just like the Bentley manual says to do. The surface was 100% straight which doesn't surprise me, it's a cast iron block it's hard to warp. I also cleaned the surface so well I could have eaten off of it. It did leak before I retorqued it, in more than one spot. Since I've retorqued it this is the only spot that's still seeping a little bit.

Was that a precision straight edge? You might get away with as much as a 0.001-0.002" warp with an MLS gasket, but if you aren't using a precision straight edge there could be more error in the straight edge than that. A precision straightedge will be flat to 0.0001" or better.