9x8

Karl, were you able to successfully retighten the silicone gasket and stop the leak? Mine is leaking as well (I probably overtightened it, I guess) - so I was thinking about loosening the pan, cleaning stuff up and re-tightening with crossmember still in place.

EDIT: Just to get stuff right, it was a front crank seal leaking, so silicone gasket is not really at fault.

Vilhuer

I have installed few silicone gaskets using studs and nylocks and its still leaking in one GT engine even after backing nuts out and cleaning up the mess. Next trick we plan to try is to press pan against block with few gargo straps and then tighten nylock just far enough than washer cannot be rotated anymore. This should allow better control of gasket compression and result even torque for all nuts as long as gasket is evenly compressed during tightening. Its also easy to do with normal tools. Especially when engine is in stand. Currently I have two engines under work which will tell how well this method works.

Cosmo Kramer

I made my own stud kit and used top lock nuts (they have a little metal locking ring inside the top of the nut). I purchased studs all the correct length, tightened them in snug into the block with blue locktite. Left it overnight, then installed the pan and gasket, just tightened the nuts by feel. I used my caliper to check the gasket and compressed it evenly (as possible) to 3 mm all the way around. No leaks.

karl ruiter

I keep meaning to take some photos and post, but have not gotten around to it. I ended up pulling the motor again and replacing the gasket. As I was debugging the CIS I had gotten the car hydrolocked with fuel and walked away in frustration. When I came back a while later the fuel had worked its way past the pistons and into the oil, and the contaminated oil sat there for a while. The contaminated oil distroyed the silicon gasket. Totally obliterated it. I count my self lucky that the front and rear main seals survived.

So...if you have a CIS car that has not run for a while, then the CIS is probably hosed. If you replacing the pan gasket before you fix the CIS I would suggest either putting in a cork gasket or, if you put in the silicon and you hydrolock during your trouble shooting process (you probably will), make sure you get pull the fuel out of the cylinders and/or change the oil right away.

I'm sure Roger would refund or replace the gasket if I asked, but I consider this to be my fault.

Since I was not sure I was totally out of the woods with my CIS I put in a cork and followed the WSM torquing process with the added step of letting it sit for a few days and coming back to torque it again (which changed things a lot). Motor is back in and leaks not a drop of nothin'.

So, after a several years of jackstands the convertable is back on the road. Idle is still a bit rough, but the quite drivable, and the top end is some serious BWAAA.

Before I pulled the motor again I tried every combination of things to try to retorque/ loosen/ clean. Of course none of it helped, but also it was not really do-able. There are about 4 to 6 fastners that you just cannot really get at with the crossmember in place.

9x8

Thought I'd share an update: wasted a day cleaning/retorqueing the damn thing and now it leaks even more.

EDIT2: Should I go with just an OEM gasket or OEM+some kind of sealant or just sealant alone? Newer porsches (like the 996 etc) use no gasket at all on their pan, just sealant.
I want to stop the leak for good, surely not up for diving there again.

EDIT3: Just to get stuff right, it was a front crank seal leaking, so silicone gasket is not really at fault.

dr bob

The silicone gaskets are great, since they are flexible and can self-adjust as things expand and contract. They are also fairly forgiving if the bolts move a bit. But only a bit. There's lots of good discussion on the best procedures for making the silicone gaskets work. There's also a lot of experience making a new cork or cork/neoprene composite gasket work. The downside to cork and the composite is that the cork tends to get crispy after a couple decades, and the cork will shrink a bit when it does. If you wait for them to leak before paying attention to bolt snugness, it will generally be too late to get it to seal again. My experience anyway.

I hear some sounds like the setscrew-studs aren't as well thought of as the double-ended studs, and that's fine. The Allen socket in the end of the setscrews makes installation a tad easier, but I've done more than a few stud R&R's with a couple standard nuts. With the aluminum block/girdle receiving whatever studs you use, they need to have LocTite on them anyway. I like the top-locking nuts with washers, but also like the flanged nuts that come in Carl's kit. The locknuts need a lot more careful attention during assembly, since it's virtually impossible to use a torque wrench or driver to get them even. At least with the flanged nuts, torque is a reasonable indicator of how much pressure is being added by the nuts. But they still need to go on with a "just barely kiss then count the turns" protocol.

So which is best? It depends... I like the composite 'cuz that's what I have in there now and I don't plan to replace it again soon. My neighbor GB recommends them for just about the same reason-- they work for him, and no need to change from something that works. There are enough wild variables in most 928 projects anyway, why add more?

Onward with progress, many like the silicone and have no trouble getting it to seal. They can be used over and over if you plan to have the sump off. They don't dry out and shrink, so once one is installed and compressed evenly and correctly, with suds and locknuts or the flanged nuts, there's no annual effort snugging the bolts up under the car by feel.


No gasket at all, just a bead of sealant? It would be tempting if there was a known and chronic problem keeping gaskets intact. The anaerobic sealers require absolute cleanliness of both surfaces during assembly. That pretty much rules out using them under the car unless you can keep ALL the oil out of the junction until the sealant is cured. I guess you could use one of the RTV gasket-maker products, but you might regret that later when it's time for disassembly.


My too sense on the issue.

Lizard928

Bob,

I use Hondabond or yamabond 4 and pan straight to girdle.
Not a drop on the bottom of my pan....

I have used the silicone ones and have had some leak, and some that dont. But the bolts like to back out regardless and seem to need to be checked once a year.