Oil Leak Fix - Attempt Number 4-6 (Somewhere in there), Suggestions on fixing an oil leak issue by the flywheel Options

[Cap'n Krusty]

It sounds to me like the problem may be to do with the crankcase pressure - not oil pressure, but blow by/ pcv system. If there is too much pressure in the case, it will blow out the seals. i haven't solved my flywheel seal oil leak issue entirely but it helped a lot when I plumbed my breather box to my carb air cleaner tops.

I have a breather box from the crankcase breather ,then to my valve cover, the crankcase is vented thru my breather, then the oil goes back to the valve cover, I still have my leak after changing the seals.

The heads AND the case vent to the breather, which is then vented to the air cleaner. The way you have it is way wrong.

The Cap'n

With the breather box people usually get there are only 3 holes, so there's only 1 way it can be set up. It's supposed to flow out the tower, into the box, and then back to the heads, but I'm not sure that is what actually happens. Seems like just having that breather box would be 'wrong'. Empi is designed to destroy imo.

That's just not true, and so is your last post. Not all 914 heads are vented. Early 1.7 heads aren't vented, nor are 1.8 heads and '75/'76 .0 heads.

The purpose of a vent is to VENT. Putting the pressure and fumes back into the area from which they're taken is simply not venting. Late 356 and 912 engines vent to the intake (carburetor) as do the carbureted 911s. Why would you think the same would not be true for a carbureted 914? On open breather box of the type you see typically advertised for VW off road use is open to the air, and is illegal in the US. It's been that way since 1965.

The Cap'n

The Cap'n

[nathansnathan]

It sounds to me like the problem may be to do with the crankcase pressure - not oil pressure, but blow by/ pcv system. If there is too much pressure in the case, it will blow out the seals. i haven't solved my flywheel seal oil leak issue entirely but it helped a lot when I plumbed my breather box to my carb air cleaner tops.

I have a breather box from the crankcase breather ,then to my valve cover, the crankcase is vented thru my breather, then the oil goes back to the valve cover, I still have my leak after changing the seals.

The heads AND the case vent to the breather, which is then vented to the air cleaner. The way you have it is way wrong.

The Cap'n

With the breather box people usually get there are only 3 holes, so there's only 1 way it can be set up. It's supposed to flow out the tower, into the box, and then back to the heads, but I'm not sure that is what actually happens. Seems like just having that breather box would be 'wrong'. Empi is designed to destroy imo.

That's just not true, and so is your last post. Not all 914 heads are vented. Early 1.7 heads aren't vented, nor are 1.8 heads and '75/'76 .0 heads.

The purpose of a vent is to VENT. Putting the pressure and fumes back into the area from which they're taken is simply not venting. Late 356 and 912 engines vent to the intake (carburetor) as do the carbureted 911s. Why would you think the same would not be true for a carbureted 914? On open breather box of the type you see typically advertised for VW off road use is open to the air, and is illegal in the US. It's been that way since 1965.

The Cap'n

The Cap'n

You're right, I guess they aren't all vented, 914 heads. I have 3 pairs of 1.7 heads that all have vents but they are from 72 and 73 models all. I guess earlier ones don't. Thanks for setting me straight on that.

About the Empi breather, the cap on it doesn't seal so it does vent to the air. They're labelled 'off road use only" but I don't think it stops people. That said, even if you had no head vents, and hooked it to just the tower then the other 2 to the carb tops, you'd basically be drawing air (unfiltered) through the top of the breather box so that wouldn't work.

My point was if the pcv system isn't hooked up to the intakes, but is just venting to the air, or worse, that it's all just sealed up, no head vents and especially if the tower breather is plugged, that could be the cause of the problem.

Could be it's the tower breather itself that's the problem? A bus breather has just a baffle plate in there and flows right through where the 914 involves a diaphragm -could be choking things up/ introducing excessive pressure.

[netbanshee]

During two of the latest seal change attempts, we did take off the oil filler cap. We noted zero crankcase pressure and the leak still persisted. We figured it was worth checking out, though there wasn't any indication that what we were seeing was related to crankcase ventilation.

As far as the OPCVs are concerned, we removed them to eyeball everything. The bottom valve comes out quite easily, but the other on the side of the case needed a bit more maneuvering to get it out (beyond just getting to it).

The bottom valve had a bit of wear and gunk on the top and sides of it, so I lightly hand filed the top to smooth it out and put it to a brass wheel to clean it up. The also cleaned up the ends of the spring.

The other valve and spring appeared to be in good shape, so I put them back in.

One thing I noticed in the bottom bore was that there appeared to be a bit of build-up where the top of the valve seats as well as a thin shallow ring of wear (like a minor scratched circular line) on the smooth surfaces of the bore about 3/4 of the way in. I was able to use metal pick to feel the wear line all the way around.

Do you think it's possible that the valve isn't seating properly at the end of the bore and/or the bottom of the valve is getting hung up at that wear point?

I've been eyeing this thread for some related feedback as well:
TheSamba.com - Pressure relief pistons & springs

Here are some pics.

Valve prior to cleanup:
(IMG:http://www.914world.com/bbs2/uploads_offsite/dl.dropbox.com-9071-1301935259.1.jpg)

Valve cleaned:
(IMG:http://www.914world.com/bbs2/uploads_offsite/dl.dropbox.com-9071-1301935261.2.jpg)

Components:
(IMG:http://www.914world.com/bbs2/uploads_offsite/dl.dropbox.com-9071-1301935263.3.jpg)

Bore shot #1:
(IMG:http://www.914world.com/bbs2/uploads_offsite/dl.dropbox.com-9071-1301935265.4.jpg)

Bore shot #2:
(IMG:http://www.914world.com/bbs2/uploads_offsite/dl.dropbox.com-9071-1301935267.5.jpg)

[TheCabinetmaker]

Man this thread has gotten hard to follow. When folks start posting about their same problem on someones thread its confusing to figure out who is saying what to who. Even with the quotes. Why don't one of you start another thread about your leak?

Sorry, I'm getting old and get confused easily I guess

[netbanshee]

vsg914 - Hoping to remedy that. (IMG:style_emoticons/default/smile.gif) Waiting for an oil pressure reading from the gauge I picked up from the Pops to offer a bit more info on engine behavior. We'll be looking at start-up and idle to see what we get.

We're considering smoothing out the bore where the OPRV sits and any relief valve adjustments that may be necessary, but waiting for more info from the car.

[netbanshee]

My Dad hooked up an oil pressure gauge to the car two days back and readings were pretty high...

Oil pressure was at:
- 40psi at initial cold start (900rmps)
- 60psi at 1800 rpms (a bit after w/ minor rev).

I have both OPRVs on order to replace (hopefully this weekend), so hopefully they show the proper fit we're looking for. We figure it's best to change both, though I'm looking at the underside one for the issues we're facing.

After installation and testing, we might consider carefully reaming out the slight ridge we found in block, in case the PRV is getting stuck there. We're not looking to play with that, if we can help it.

Hoping that the main PRV worn a bit undersize, since it fell out way too easily from the block. Taking it out was the complete opposite of needing an extraction tool to pull it.

[netbanshee]

Hey everyone... been quite a bit. There are definitely some developments that I'd like to share.

After replacing the piston in the main oil pressure relief valve, we still had an oil leak at the same spot (at the rear seal side of the flywheel). Looks like she wasn't being caught in the bore.

From here we decided to split the case to look around and clean up, did a bit more research on the heads and picked up another used longblock and some extras that we found nearby for a good price. I also purchased a used flywheel, clutch and pressure plate on the cheap from eBay to test out and see if we can produce any noticeable differences.

The original case in the car was was in pretty good shape as was the crank. The heads look to be 1.8 bus heads and the pistons were dished. The longblock that we picked up also had 1.8 bus heads, an earlier case (70-71 914 case) and domed pistons.

After cleaning up the original setup and honing the cylinders, we reassembled it, and still had the original issue. We then proceeded to use the extra case we picked up with the original cases' internals to see if the original case was the issue. The same leak persisted. After that, we placed the "new" crank in the extra case and proceeded to see a smaller leak at the rear seal, but we also had a leak at the main seal as well.

Oh well. If anything, I now have a pretty good handle on the engine top to bottom and with jack stands and a lift set up, I can drop a motor and have it down to a shortblock in 45mins. Pit crew here I come. (IMG:style_emoticons/default/driving-girl.gif)

In the meantime, we decided to bite the bullet and get things checked out. We contacted Dennis at Valley VW and arranged for an original case check, crank check, head check and delivered other internals to get a look. We're possibly looking at getting the case line bored, replacing the cam and lifters, all new gaskets and seals all the way around.

Depending on the results we et back by early next week, I might look at replacing the pistons, wrist pins and jugs, though the verdict is still out.

I'm hoping that by next week, I'll have some new and recut and conditioned parts in my hands to put the whole setup back together.

Wish me luck, but if anything occurs to any of you about the situation, I'm more than happy to take a look. It's easy in a long post and an incomplete set of notes that I glossed over some details.

Cheers,
Sean

[simonr]

How are you installing the seal. I tried tapping them in twice leaked like hell both times . I then used a cigar box lid and tapped the wooden lid instead of directly on the seal and it worked like a charm . the seals are very sensitive to indents no matter how lightly you tap them in.

[netbanshee]

Simonr,

I've installed them with a ball peen hammer, either lightly on the surface or with a board or flat element across the surface. I make sure that it seats completely against the surface and have used National, Elring Klinger and Victor Reinz seals a few times. We've also used anaerobic sealant on the surface from time to time.

In addition, we friended a local Type IV motor rebuilder who looked at our process and didn't see anything glaring with the engine or seals.

Our feel is that the bore or the crank is a bit off on the end... if they're beat up just a little over the life of the engine, it's totally possible that the seal isn't being maintained and the leak can emanate from there.

Sean

[nathansnathan]

I picked up a few of these seemingly over priced seals from gowesty - seems they are the legendary 'thicker' seals. I haven't tried them in an engine yet though. Check out the write up
http://www.gowesty.com/library_article.php?id=535

[914itis]

I picked up a few of these seemingly over priced seals from gowesty - seems they are the legendary 'thicker' seals. I haven't tried them in an engine yet though. Check out the write up
http://www.gowesty.com/library_article.php?id=535

interesting article. I hope that is the solution. 29 bucks I well worthed .

[netbanshee]

nathansnathan / ppetion,

Talk about synchronicity. I had a conversation about the thicker seals just a day or two ago with my pops since it came to his attention as well. The article is great backup. Will definitely look into it.

Since we're already full bore (yuk, yuk) into the project, I'm hoping that having new bearings, gaskets and the like will be the added refresh this teener needs to keep her reliable.

I haven't driven her since November and we have a '63 Ghia convert that needs a little bit of love before she's on the road too.

Thanks,
Sean

[netbanshee]

Well... a long time, but finally some good news.

I purchased a nice new flywheel recently after my father and I cleaned up the whole case, dropped in new bearings throughout, checked the threaded gallery plugs, etc.

We also had another case that we picked up to compare and source parts from. Inside of that case, we had an older, thicker "West German" rear main seal that was in great shape.

We removed it when we split the second case, pressed it deeper into the rebuilt one (past flush with the outside) and did the rest of the assembly. After about 25-30 minutes of running the car, not a drip in sight. (IMG:style_emoticons/default/biggrin.gif)

So, all in all, it does seem that the thicker rear main seals do provide a better seal than the standard ones. On top of that, making sure that the flywheel is in great shape and that the seal is pressed in farther than flush with the outer part of the case does make a big difference.

Since we ended up turning this into a bigger project by pulling apart the whole drivetrain, we could have affected other things in the engine, but nothing as directly as the last steps in terms of the oil leak issue.

Seeing that aside from the car being in storage, I haven't driven her in 11 months total, I see where this upcoming weekend is heading. (IMG:style_emoticons/default/driving.gif)

Anyone curious about any other observations or anything from the whole process?

Cheers,
netbanshee