944hal

Given the wealth of knowledge on this forum, I'm curious to see if anyone else has this problem. I just did a complete engine rebuild (2.5L 944). Started with a bare block and replaced everything, all bearing, seals, etc. That included the rear crank seal. The engine got oil pressure quickly, and on startup, ran for 45 min with no leaks. I shut if off and left it for about 15 min. On returning to the garage there was oil under the car, easily traced to the rear main seal. I took it back apart and replaced the seal. Same story. It ran for almost an hour with no leak. After I shut it off, the leak returned as before. I took it apart again, and used a OEM seal. Same result. Since, I have dried off the oil pan and cross over (it's a turbo) and run it again. Same story. NO leak while running, but it leaks after it is shut down. It doesn't continue leaking either. After a couple of drops, it stops until the next time. End of story, I don't want this post to be never ending, so, any ideas?
Thanks

tempest411

Did you use sealant on the outside edge of it when you did the installation each time?

FRporscheman

If you do a search, you'll find a lot of info on this topic. Many people have had problems getting the RMS to stop leaking.

Read these two threads:
https://rennlist.com/forums/924-931-...lling-rms.html
https://rennlist.com/forums/944-turb...ml#post4389625

Van

You did install it in the correct direction, right?

And the interfaces between the girdle and the block don't have any "steps"?

Did you happen to have the crank journals bored or honed on the block?

mytrplseven

Can you confirm if it's leaking from around the periphery of the seal or on the inner surface where the crankshaft goes through? You might consider a cheap flourescent dye tracer kit from your local auto parts store. They're cheap and they are magic at tracing leaks to specific spots. I'd recommend it before you take anything else apart.

snb13

http://www.944online.com/cgi-bin/yab...num=1387072813

944hal

snb13
Thanks for the link. That's exactly what happened to me and the seal leaked in the same spot. I counter sunk the first seal, and flushed the second. I did notice the difference in the depth of the seal, along with the rubber coating on the outside, being different from the OEM. The last one I put in was an OEM and I counter sunk it to the flange. Not as far as the pic in the link, but then again, it was an OEM and not a Victor Reinz. However, it still leaks. It's not bad, so I guess I will live with it for the time being. I guess the last 2 or 3 seals I did, I just got lucky.

Thanks guy for all the comments. BTW.....Van, I had the crank journals polished but not drilled. I added an oil scraper and the Michael Mount rod conversion. No girdle "steps" either.

FRporscheman

Did you use loctite 574 in the 2 spots next to the RMS?

944crazy

Is it possible to install the RMS by slipping it over the crank and installing it with the crank when you assemble the engine?

CVR_Rally

So flush is the way to go then? That's what was in the 944online article at least.

I bought some PVC to tap it in too and plan on using CurilT while I'm at it. I'm a bit far off as I can't install it till the engine is off the stand so I'm glad this thread popped up (not glad you have a leak though).

Chris

FRporscheman

No, I wouldn't install it flush, I'd at least go in until the chamfer on the crankcase is passed.

Also I wouldn't install the RMS onto the crank before installing the crank. The RMS could get pinched by the girdle/crankcase, and scraped-off curil T could get stuck between the girdle and crankcase, which could cause problems with those two pieces mating together correctly.