Carl Fausett

My oilpan gasket is 1 year old - just last year I replaced my connecting rod bearings and of course installed a new pan gasket. I have torqued and retorqued the bolts, but the gasket is all soft and swollen and has migrated to the outside. I think that the OEM cork oil pan gasket is at fault here... too soft and too porous a material for the synthetic oils that can capillary right thu them. Has anybody else experienced this with the OEM oilpan gasket?

I am making a replacement out of more modern neoprene-synthetic gasket material. I'll let you know how it works.

dr bob

There was an interesting thread on this subject a year or two or three ago. If you find that you are squishing out your sump gasket, it's most probably be cause YOU are squishing out your sump gasket. The torque spec on the bolts is just barely north of finger tight on those little 6mm capscrews; anything more will displace the gasket and then it's a leak no matter what you do.


One of the suggestions at the time was to do without the gasket completely, and use one of the anaerobic gasket goo products like Yamabond/Hondabond or the Locktite or Permatex equivalents. The one that GM recommends is about $25/bottle, and has a usable shelf life of maybe 6mos unopened and refrigerated, and a only few weeks once the top is cracked. The upside is that, once installed and torqued correctly, this stuff seals really well and permanently.

For those of us that have worked on Ferrari and Jaguar engines, these sealers have been lifesavers. In spite of the wonderful appearance of some of the engine sandwich castings, they fall way behine when it comes to holding a gasket well. The gasket-in-a-tube products make dry engines a possibility.


Cheers!

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jpitman

Dr Bob, Has anybody actually got any experience with a joint sans gasket to report yet? I have experience of old Rover 4 cyls with iron block/cast alloy pans that used many small bolts as in a 928, and no gasket, just Loctite, and never leaked. Failing that, a more robust cork/rubber composite gasket might be a longer term solution, but dont know if you can buy this material in sheet form?
jp

Mike Schmidt

There's a replacement gasket that's supposed to be made of a better material on Ebay. They're also available directly from the guy. The auction is at: <a href="http://cgi.ebay.com/ebaymotors/ws/ebayISAPI.dll?ViewItem&item=1809899143&r=0&t=0" target="_blank">http://cgi.ebay.com/ebaymotors/ws/ebayISAPI.dll?ViewItem&item=1809899143&r=0&t=0</a>

Carl Fausett

Thanx, Dr Bob! That is exactly what I was thinking of. I have those gaskets from that fella on eBay that are a better/more modern composite material, but I was really thinking of just going sans-gasket with a good sealer. Think that is what I'll try.

Chris Lockhart

Quick Carl, I'm having the same problem with my GT. I replaced the pan gasket about a year and a half ago, and now it's leaking again. I duplicated Marc Thomas' procedure from Greg Nichols Tips page, using YamaBond 4 on both sides of the gasket, and dipping each bolt in it also, before installation and torquing. All was dry until about 2 weeks ago, when I started to notice some oil spots. Up on jack stands we go and all the bolts are loose!!!!!! I gently retightened them, which helped quite a bit, but it is still leaking some.

Dr. Bob--- I like the idea of using a sealer only, with no gasket, but will the bolts be OK as is, or will I have to buy shorter bolts????? It's been so long, that I don't remember how deep the threads go. <img src="confused.gif" border="0">

dr bob

Chris wrote:

&gt;&gt; Dr. Bob--- I like the idea of using a sealer
&gt;&gt; only, with no gasket, but will the bolts be OK as
&gt;&gt; is, or will I have to buy shorter bolts????? It's
&gt;&gt; been so long, that I don't remember how deep the
&gt;&gt; threads go

I'm in new territory here, since I've never had to replace the sump gasket. Just passing along the references to the earlier discussion.

I also know, after looking at how those bolts fit in there, that I would be replacing almost all of them anyway with some little socket-head capscrews with star washers or similar. The socket-head part allows you to use a ball-end hex bit on the inch-pound torque wrench/screwdriver, and the star lockwashers to help keep the bolts in there once they are torqued correctly.

The Yamabond that Marc recommends is what I've used sans-gasket on several little motors, specifically the TZ motor in the LeGrand and the Rotax engines in the baby boats. These are two-stroke engines in extreme service, and cannot afford any leaks of either oil from the gear sections or air leaks into the crankcase cavities. The Loctite (don't remember the number...) is what I like for the sump sandwich sections on engine castings. This is the cures-when-deprived-of-air product with the short shelf life. I'd probably opt for the Loctite product for the oil sump on the 928 if I had a continuing problem with sealing.

On some of the less-stressed engines, I've been able to use the orange hi-tem gasket maker stuff when I didn't have time to wait for the Locktite stuff to cure. This stuff is great for exhaust water-jacket gasket replacement on the bigger boat when the old gasket has gone away and none are available quickly. I did a quicky fix a few years ago n that and no problems since. I do have the new spare gasket in the toolbox in the engine bay, just in case I ever have that manifold off again...

Point here might be that there are newer products, stuff not available when the engine was first designed, stuff that will do the job a lot better than a cork gasket in between two aluminum casting sections.

I guess if I was designing the sump gasket from scratch, it would be a metal-shim gasket with silicone continuous-bead face seals. I put a set of these in my Ford where the cork had failed, and they worked great. I gave good thought to going the gasketless route on that engine, but had the gaskets already when I tore it apart.


A call to Loctite or Permatex might net a firm expert answer on this whole issue, by the way.


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Mike Schmidt

Part of my winter project list was to replace the motor mounts, so I took the oil pan off to put in a baffle as long as things were apart anyway. When I took the pan off, I was very surprised at how loose some of the bolts were. There were a couple that couldn't have even been contacting the pan flange. What's really surprising is that the pan has been absolutely dry the whole time I've owned the car, even with the bolts being so loose. When I had all the bolts out, it still took a little doing to get the pan off because of it being stuck on. It looked like a very little bit of some sort of dark or black sealer had been used on the gasket. I wish I knew what it was now. Did you guys throughly clean off the mating surfaces when you put the pan gaskets on, including wiping them off with a solvent?

Chris Lockhart

Thanks Dr. Bob. I'll check them out before doing the pan again. I actually bought some star washers when I did the pan originally, and the OD was too large for the recesses. I figured that MT had such good luck with his procedure that and claimed something like 200K miles with no leaks, that I wouldn't worry about it. I regret that decision now!!!!!!

Mike, I cleaned the mating surfaces thoroughly before installing the new gasket with the YamaBond 4. I actually glued the gasket to the pan the night before, then applied the sealant to the top of the gasket before installing the pan. Dipped each bolt in the sealant before installation. It really seemed to work great, and I was impressed. Last oil change about a month ago, all looked great, but I haven't been checking the bolt torque. I figured I didn't need to because of what Marc Thomas had said in his post. Figured that the YamaBond would be a good thread locker. When I went to re-tighten the bolts last weekend, there were only a few that were still tight from the threadlocker/sealant. Most were finger tight. Even with the ones that were tight, you could spin the washers with your finger. I guess thats from the cork shrinking??? I wish there was a gasket available like the more modern engines are using. The kind that Dr. Bob mentioned with the metal frame and silicone bead. I know Harley Davidson stopped their cylinder base gasket leak problems by switching to this type of gasket. 95 years of leaks fixed with one new gasket design. LOL.

BTW Mike, you'll get to check out the new cowl induction hood at SITM. You are coming aren't you??? The hood is complete minus final paint, and I've been running with it since last weekend. Gotten alot of thumbs up from the general public, and even a few" it looks cool" coments from some 928'ers. It's definitely not everybody's cup of tea, but I like it.


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Mike Schmidt

I'm planning to be at SITM, and already have my reservations. Hopefully the car will be back in one piece by then, and if it is, hopefully the oil pan won't be leaking.