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

[netbanshee]

Hey everyone,

Been reading the forums for some years, but haven't had much to say up until now. So Hi, Hey and Hello. Nice to meet you.

I'm looking for some feedback and/or recommendations on an issue my '70 914 1.7l is having. After replacing the flywheel seal a few times to no avail, my father and I are starting to look at a few other options and suggestions.

Here's the car (upon delivery and there on):
http://www.flickr.com/photos/netbanshee/27...in/set-1076179/

Regardless of what's been done so far, the car still manages to leak oil at about a drip every 1-2 seconds out of the bottom of the engine near the flywheel. The oil leak persisted after the car blew an oil galley plug behind the flywheel. Before the car decided to dump most of her oil out in the driveway, I was able to shut the car off and keep things from getting much worse.

We proceeded to pull the engine and tranny, pull all of the galley plugs and threaded in some new ones. We also hit them up with JB Weld for added assurance.

At this point we went ahead and gave the drivetrain and a good once over. We hadn't really pulled apart the car since I purchased it 3 years ago, so no better time then. The car was generally pretty solid up to that point since the owner kept the car in good shape and only put a few thousand miles on the car over the years after an extensive restoration.

We checked the pressure release valves, replaced various gaskets, the fuel lines, relocated the fuel pump under the gas tank, fixed up the hell hole before it got away from us, etc., etc. We then went about replacing the flywheel seal and flywheel o-ring. The 3 shims were in good shape so got them cleaned and lubricated before putting them back in the way they were. We permatexed the outside of the flywheel seal, seated it, bolted everything back up and got the drivetrain back in the car.

After starting the car, we started to get the oil leak I described. Since then, we have tried different flywheel seals (Elring Klinger at first, then Victor Reinz since) to no avail. We made sure that the end play on the crank was between .003 - .004mm and that we seated the seal flush with the case and in slightly different depths so it didn't ride in the previous spot. Also of note, the leak is definitely between the flywheel and the case. There isn't any foul smelling gear oil from the tranny to note.

There isn't any indication that the galley plugs are anything but solid, so our thought was that there was an issue with the flywheel seal. Now that we've replaced it a few times, we're looking at other options.

We were thinking that it might be time to replace the flywheel and bolts. The paperwork I have on the restoration suggests that the original flywheel was machined and polished (dual surface) and we did notice that the flywheel seal we initially removed (don't have it anymore) was white and nothing we had seen before. Possible the seal was a different type?

So, what does everyone think? Any other ideas or suggestions beyond a new flywheel?

Thanks,
Sean (netbanshee)

[netbanshee]

Some updates...

The place I attempted to order a new flywheel, but it was out of stock. Also found out it was a Chinese unit, so I decided to cancel the order. I've read that they're less than desirable.

Since the original flywheel seemed to be in decent shape, I'll probably just send it out to be done up.

The other thoughts that my father and I had were to replace the three shims with newer ones and see if there are undersized flywheel seals available.

Does anyone know of a good spot to pick up a flywheel shim kit or do they usually have to be separately purchased?

Also, anyone ever hear of an undersized flywheel seal? Since the one we pulled out wasn't one we regularly recognized (white seal), we thought it might be a tad different than the typical ones you'll find.

If we can't get this to pan out, we'll likely look at either disassembling the entire block to have it redone or maybe take the plunge and make the move from the original 1.7 to a 2.0.

If anyone knows of a good thread here on upgrading a motor and what problems are regularly encountered, I'd appreciate it.

[netbanshee]

We bought some slightly undersized NOS seals to place that look very much like the seal we had in when we got the car. Will see. I have no background on how the car was explicitly handled internally when it was refreshed.

I also have a lead in the area with someone who has major experience rebuilding Type IV motors, etc. that we're talking to. Might be worth cracking open the short block and seeing how things are.

[MartyYeoman]

Have you tried using a Ready-Sleeve?
They're available through NAPA stores.
The 75mm one will cover/restore the sealing surface for the rear main.
It's about a .25mm thick wall. Adds some extra tension to the stock seal.

[netbanshee]

Thanks to everyone who reached out so far. :)

After chatting with a local dealer mechanic who then put us in touch with a Porsche mechanic, I think we have a good lead.

When we pulled the Oil Pressure Relief Valves, they came out way too easy. The mechanic suggested that they were worn and weren't seating properly. If they're not functioning, the pressure in the case is climbing very high and the rear seal couldn't possibly hold that back. He felt pretty confident that this was the issue.

I don't have a oil pressure gauge in the car, so I wasn't being provided any warning of rising pressure. If the OPRVs were sticking, there goes the oil galley plug that started the whole scenario and then on.

So... off to find some valves. Would it be a good idea to track down completely new ones or can components be replaced (spring, etc.)? Also, it there a difference between valves for a regular Type IV or are they specific to a 914?

[Cap'n Krusty]

In all you've written, I don't see a single mention of the flywheel o-ring. It MUST be in good condition! I would also look for pitting or a wear mark on the sealing surface of the flywheel.

The Cap'n

[netbanshee]

Cap'n

We replaced the O-ring when we first dropped the motor and saw the blown oil galley plug. The original one was in decent shape, but didn't want to take any chances. There wasn't a older one to be found underneath (seen that mentioned in other threads).

Recently I also picked up a new crusher washer and new flywheel bolts because, why not? The current set-up appears and torques fine, but it's good to have spares on hand.

I never saw oil making it past the flywheel and onto the clutch, etc. In fact, the clutch has only light wear and text is still clearly visible on the surface. I haven't driven it too much since I obtained it and the the car was refreshed by the previous owner.

The flywheel surface appears to be in good shape and doesn't exhibit any amount of pitting or wear on it. If polishing it up could provide any help, I'd be for it. When I was considering ordering another, it was more of a trigger-finger reaction (not that a few hundred wouldn't have hurt).

We did seat flywheel seals at a few (minor) different depths when we pulled the motor after seeing the oil leak appear again. Only when it was out from the case a bit farther did it ride the outer surface of the flywheel a little bit. Otherwise, we've kept it flush to the outside of the case.

Also of note, we kept end play at .003 to maybe .004 each time we got back in there, so we've been good on that front.

All said, it kinda feels right in my gut that the OPRVs are what could be causing the issue. I was also considering a oil pressure sender unit and vdo gauge to see what was going on in the case.

Any ideas on where I could find those and if they are different between a standard type iv motor and a 914 1.7l?

I appreciate the outreach everyone. I want to get this car on the road for Spring-Summer and finish up a 63 Ghia vert as well. Living in PA gives me a smaller window to play with. (IMG:style_emoticons/default/smile.gif)

[Cap'n Krusty]

My mistake, it's in the original post. Accept my apologies. I have my doubts about the OP relief valves, but there's always that remote possibility. How about crankcase pressure? Do you have FI or carbs?

The Cap'n

[tradisrad]

I had an oil leak coming from the drivers side stud that the trans bolts onto. It seems that the hole was drilled too deep and it had a small opening into the case. Loctite fixed it. This is probably not your problem, but it may be worth a look.

The way I understand the oil system is that with too much oil pressure the large relief valves opens and oil bypasses the cooler and goes directly to the galleys (you replaced the plugged ends). the same goes on the small valve, but oil is drained to the case. (correct me if I am wrong).
So, my point is that with weak or worn oil pressure relief valves you would have low oil pressure and it should not be blowing past the crank seal.
Now if they were jammed all the way in and could not move or had excessively strong springs you would have high oil pressure, but you said they came out easily (no smoking gun?). I think mine basically slipped out right behind the spring.

[Ericv1]

I went through a similar situation on my first 914 many years ago. I had the engine out at least 4-5 times replacing the flywheel seal. Turns out it was the transmission input drive shaft seal. I replaced it and all was well. I had no leaks for a very long time. It might be something to consider if it hasn't been done.

[netbanshee]

Sorry it took me a bit to get back. Busy weekend (IMG:style_emoticons/default/smile.gif)

Cap'n - I haven't checked crankcase pressure yet, though I'm pretty sure my father had eyeballed it. Since the car is upstate from me, I only see it on the occasional w/e I get to go up. The car isn't stock FI (wish it was) and it runs a single carb.

tradisrad & Ericv1 - When we're in there next, I'll take a look around.

When talking to the Porsche mechanic, he noted that he saw this happen to a few 914s in the past. When the OPCVs wear out, they have a tendency to cock in the bore and catch the oil alley hole. The spring pressure then keeps it stuck and the pressure spikes.

We're currently looking to replace these and might have a line on them. I should be heading back upstate next w/e, so I'll let everyone know how things look afterwards.

Thanks for the options and information so far everyone. (IMG:style_emoticons/default/smile.gif)

[914itis]

Sorry it took me a bit to get back. Busy weekend (IMG:style_emoticons/default/smile.gif)

Cap'n - I haven't checked crankcase pressure yet, though I'm pretty sure my father had eyeballed it. Since the car is upstate from me, I only see it on the occasional w/e I get to go up. The car isn't stock FI (wish it was) and it runs a single carb.

tradisrad & Ericv1 - When we're in there next, I'll take a look around.

When talking to the Porsche mechanic, he noted that he saw this happen to a few 914s in the past. When the OPCVs wear out, they have a tendency to cock in the bore and catch the oil alley hole. The spring pressure then keeps it stuck and the pressure spikes.

We're currently looking to replace these and might have a line on them. I should be heading back upstate next w/e, so I'll let everyone know how things look afterwards.

Thanks for the options and information so far everyone. (IMG:style_emoticons/default/smile.gif)

I am watching this thread close, I just finished putting everything back on mine, everything feels great, changed all the seals and I am also still leaking by the flyweel. waiting to see the results here before attempting to do anything.

[netbanshee]

Just got back from some investigation back home this w/e.

We didn't pull the motor to check out the seal, flywheel, etc. this time since we had to work on my sis's Focus. I did, however, find out some more things about the car and also got to inspect, clean and reinstall the OPRVs. My dad also picked up a oil pressure gauge (not VDO, but shows up to 100 psi) that we'll use to get more info.

I'll list some updates in this post about the car and talk about the OPRVs in the follow-up. I also have some photos to add. Since I shoot for articulate posts, but they're probably better read in smaller chunks. (IMG:style_emoticons/default/smile.gif)

About the car:

I added the car's VIN and other credentials into the site's db. Looks like the PO had put the car in shortly before selling it to me and added the info as well.

PO listing:
http://www.914world.com/bbs2/index.php?act...mp;viewid=11409

My listing (flickr pic doesn't show):
http://www.914world.com/bbs2/index.php?act...mp;viewid=13729

The original listing isn't completely accurate, since the motor is actually a '74
1.8l L-tronic (EC025257). That means it wasn't dealer updated till at least '74 or after. At least I got a side-shift tranny out of the deal. (IMG:style_emoticons/default/smile.gif)

The single progressive carb on it appears to be a Holley (L7760 / 1361) as well. Might have been updated even after the dealer's install, but I did note that there was the difference between D-tronic and L-tronic over those years, so maybe it was a shortcut put in to deal with that.

Car was also made in Dec '69 and if the serials were sequential from 0, it's likely the car was the 1152nd manufactured and released to the states. Pretty cool.

I'm not sure if this information offers any insight into the car, but I figured it couldn't hurt digging in a bit more.

[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.

[914itis]

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.

[nathansnathan]

I'm not sure if the stock system generates any vacuum in the case, so it may just be helping the problem to have the added vacuum by hooking the breather to the intake.

It seems to help though. it only leaks for the bit after I shut it off. When the oil cools, it seems to not leak. I see drops but it rarely gets low. I've read about this vacuum making the seals squeel actually, but I have'nt heard that happen. Before I upraded my breather I had the empi one hooked up to the tower and the (edit)heads. I'm sure it's better than plugging them.

This is something I'd like a resolution to as well. I've heard urban legends about a thicker seal, maybe it's a Vanagon seal?

[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

[914itis]

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

Where is the head vent on gne 1,7? and using dual webber carbs

[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

Where is the head vent on gne 1,7?

I just edited my earlier post where I had 'valve cover' on the brain from what ppetion was saying. 914 heads all have the breather holes in them, from the 1.7 to the 2.0 as far as I know. People sometimes drill holes in their valve covers to make a breather for a bus head that has no hole in the head itself, but 914 heads you shouldn't have to.

[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.