transmssion/engine seal and headers

cellison · 09-30-2009, 02:09 PM

i have been talking to gentleman about purchasing his 930, but have not yet seen it in person. it sounds like it is nice shape.

one thing he mentioned is that "there is a little bit of fluid which seeps out around the transmission to engine seal, but it never builds up to a drip, and is easily wiped clean at each service". i'm definately going to investigate further, but what could be the cause? other than that the engine is dry.

also it has the factory 930 european headers including all the turbo components and piping. is
there any advantage to this set up vs an aftermrket B&B, GHL or similar?

willtel · 09-30-2009, 02:39 PM

There isn't really a seal between the engine and trans so it can't be leaking there. The oil could be coming something difficult to replace like the main seal or it could be something simple like the PCV tube leaking above that area. Hard to say without some pictures.

mark houghton · 09-30-2009, 03:05 PM

Assume the worse...main seal...and use that as leverage to dicker with the purchase price accordingly. If indeed the main seal, then eventually you'll be replacing the clutch as well if it gets oil soaked.

Hayabusa · Hayabusa's Garage

What year, Charles?

x98boardwell · x98boardwell's Garage

Mark is correct. As long as it is oil and not transmission fluid it would have to be the rear main seal. This seal can be changed by removing the transmission and clutch and costs around $20 or slightly more.

If the leak were to worsen, it can ruin the clutch but would take a huge leak to make this happen. But, depending on the mileage it may already need a clutch anyways in which case good time to change the seal. If the motor were rebuilt it could also be the case seeping on that end but I'm guessing it would most likely be the rear main.

A couple of pictures for reference. The first is before I rebuilt the motor and the second is after when I was buttoning everything up. The third picture is when the flywheel was back on which covers that seal again for reference. The flywheel bolts are a "one-time-use" item and you should purchase new ones if you fix that leak.

Best of luck in your purchase.

mark houghton · 09-30-2009, 05:11 PM

One other thought. Perhaps the leak originates from somewhere near the top of the engine. What comes to mind is the oil thermostat that sits toward the back of the engine in an impossible to reach place without taking "stuff" off. Its o'rings are prone to dry out over time and leak a puddle of oil on top of the engine. Perhaps it's drooling down to eventually collect where it's visible. Probably just one of many possible leak sources, but I would still suspect the one in closest proximity to where it's visible.

It's kinda like a leak in your roof at home...the damn thing can travel a long ways before it becomes evident as soggy ceiling sheetrock and a wet spot on the living room floor that does not smell like dog pee.

willtel · 09-30-2009, 06:16 PM

Quote:

Originally Posted by mark houghton

One other thought. Perhaps the leak originates from somewhere near the top of the engine. What comes to mind is the oil thermostat that sits toward the back of the engine in an impossible to reach place without taking "stuff" off. Its o'rings are prone to dry out over time and leak a puddle of oil on top of the engine. Perhaps it's drooling down to eventually collect where it's visible. Probably just one of many possible leak sources, but I would still suspect the one in closest proximity to where it's visible.

This is what happened in my case. I knew I had a minor leak but couldn't find it until I pulled the drivetrain to rebuild the trans. My crankcase vent hose had separated and the top of the engine was being misted with oily vapor. This all collected and ran down to the lowest spot on the bellhousing.

You can see some of the grime here. The volume of the leak was very small but the mess it made was huge. My main seal was in great shape.

RarlyL8 · RarlyL8's Garage

Factory "Euro" heat exchangers were OEM on all 930s from 1980-1989. The only other style is the US '78/9 which are restrictive. Aftermarket headers are better but to what degree depends on the header.

cellison · 10-02-2009, 03:52 AM

Quote:

Originally Posted by Hayabusa

What year, Charles?

chris, this one is a 79.

I was in Seattle last month and looked at two both 1976 930s i saw on craigslist. one was origionally brown, but it was repainted according to the sticker in the trunk in a metallic brown for a GMC truck and had the GMC paint code listed. that car had other issues. looked at another 76 black, repainted fairly decent but not great, mechanically was good/ran stout, but the repaint and apparent body work concerns turned me away.

i keep looking for the right one.