Oil leak on side of chain housing?

[djb25]

Hi everyone,

Does anyone know where this leak could be originating?



I wiped the side of the chain housing off and then ran the engine on the lift for a few minutes. Fresh oil is clearly visibly running down the side as seen in the photo.

I can’t quite figure out where it would be coming from, though.

Anyone have any idea?

[JSV798]

This looks like the camshaft seal; it sits between the chain case and the camshaft carrier. I had this 5 years ago. Involves removing the camshaft covers and the chain sprockets so there is a danger of losing the cam timing. I did this without removing the engine but the exhaust box needs to be removed.

Roy

[djb25]

ugh.

that sounds like a winter project.

[mikedsilva]

Originally Posted by djb25

ugh.

that sounds like a winter project.

An afternoons work

[yelcab1]

First timer, weekend project.

[David Inc.]

Originally Posted by JSV798

This looks like the camshaft seal; it sits between the chain case and the camshaft carrier. I had this 5 years ago. Involves removing the camshaft covers and the chain sprockets so there is a danger of losing the cam timing. I did this without removing the engine but the exhaust box needs to be removed.

Roy

Can this even be done without rechecking cam timing? Or can you get away with match marking everything before disassembly?

[porsche930dude]

One winter i ran my car and it was pouring out of there. Went for a quick last drive got home and it was healed and never leaked again. I still have nightmares about it

[shoooo32]

I wouldn't attempt it without the ability to verify cam timing. The Z block and indicator are inexpensive and the peace of mind will be priceless. Also of note, it's 10x easier to do this with the engine in the car if you remove the rear bumper.

[Flat6pac]

you’ll need to remove muffler and sheet metal. Start motor to get oil to the tank and out of case. Remove cover and set on Z1 with keyway up. Remove nut or bolt and tensioner
Carb spray the area including the chain
Fingernail polish 2 or3spots on the chain and chain wheel and the pin location
Pull pin use spark plug top threads to fit pin threads. Remove the chain, chain wheel, backing gear, shims, woodruff key.
3 6mm bolts will remove cam cover. Replace the rubber Oring and paper gasket. Locate the paper gasket with 2 bolts to keep the gasket in place lube the rubber
O ring and make sure it doesn’t crimp in the tightening.
Good luck,
Bruce

[PeteKz]

Do some more investigation before you start tearing part the chain cases. You MUST find the source of the leak first. Another possibility that I've had: Leaking oil hose/pipes to the cam housing, or the banjo bolt and washers on the cam housing.

[djb25]

Thanks for the info, everyone.

It shouldn’t be too difficult to verify the exact source of the leak, you can see the fresh oil that ran down within a minute or two (I had wiped the chain box off before running the engine).

Also - could this be from a leaking rocker seal? it doesn’t seem like it would be, but i thought i’d ask.

[proporsche]

Originally Posted by David Inc.

Can this even be done without rechecking cam timing? Or can you get away with match marking everything before disassembly?

Yes it can be done without checking the cam timing providing you follow what Bruce has said above.Main thing is,Z1 and leave spark plugs in..also to have the correct crow foot tool helps on the early models.

Ivan

[Jeff Higgins]

Originally Posted by shoooo32

I wouldn't attempt it without the ability to verify cam timing. The Z block and indicator are inexpensive and the peace of mind will be priceless. Also of note, it's 10x easier to do this with the engine in the car if you remove the rear bumper.

Best advice on this thread. There is no way on earth I would ever even consider removing the camshaft sprocket and timing chain without checking cam timing on reassembly.

Originally Posted by proporsche

Yes it can be done without checking the cam timing providing you follow what Bruce has said above.Main thing is,Z1 and leave spark plugs in..also to have the correct crow foot tool helps on the early models.

Ivan

Absolutely the worst advice on this thread. See above.

I've had the misfortune of having had to do this on both sides of a couple of motors. Both are 3.0 liters, one relatively stock with SC cams and the other my hot rod MFI motor. The paper gaskets, the triangle shaped ones, failed on both. I had applied Curil T to them per the recommendation given in Wayne's book on how to rebuild your 911 motor. Well, it appears as though Curil T actually softens, or even almost dissolves, whatever material that is used for those gaskets. At least in the rebuild kits I used.

In all four cases I marked everything with a dab of paint on every critical feature. I reassembled with the paint dabs lined up. I checked timing anyway. Two of the four were not timed correctly after reassembly. Not off by much, but nonetheless not correct. Chain stretch? Some other factor? Dunno. What I do know is that it convinced me of the value of checking.

This is so darn easy to do once you are in there anyway. I've never found the lazy, half assed approach, skipping important steps, to be rewarding in any way or to pay off in the long term on these cars. In this case, the tools are cheap, and it only really adds maybe half an hour to the project. Absolutely worth the peace of mind.

[proporsche]

Originally Posted by Jeff Higgins

Best advice on this thread. There is no way on earth I would ever even consider removing the camshaft sprocket and timing chain without checking cam timing on reassembly.



Absolutely the worst advice on this thread. See above.

I've had the misfortune of having had to do this on both sides of a couple of motors. Both are 3.0 liters, one relatively stock with SC cams and the other my hot rod MFI motor. The paper gaskets, the triangle shaped ones, failed on both. I had applied Curil T to them per the recommendation given in Wayne's book on how to rebuild your 911 motor. Well, it appears as though Curil T actually softens, or even almost dissolves, whatever material that is used for those gaskets. At least in the rebuild kits I used.

In all four cases I marked everything with a dab of paint on every critical feature. I reassembled with the paint dabs lined up. I checked timing anyway. Two of the four were not timed correctly after reassembly. Not off by much, but nonetheless not correct. Chain stretch? Some other factor? Dunno. What I do know is that it convinced me of the value of checking.

This is so darn easy to do once you are in there anyway. I've never found the lazy, half assed approach, skipping important steps, to be rewarding in any way or to pay off in the long term on these cars. In this case, the tools are cheap, and it only really adds maybe half an hour to the project. Absolutely worth the peace of mind.

Jeff..some people as the OP do not know how to set the cam timing or has the tools..If you are careful it can be done...For me, i always check the timing,the tools are not that cheap ,since you are mentioned it ..for some person who does this once in their live..

the worst adviser here;-)

Ivan

[pmax]

Before you dig into it ...


more Italian tuneups and yeah, change the oil.

[proporsche]

Originally Posted by pmax

Before you dig into it ...


more Italian tuneups and yeah, change the oil.

Are you suggesting to put in the oil some kind of powder to stop the oil leak,, as an italian tune up?
Ivan

[PeteKz]

djb25: If it was a rocker shaft leak, I would expect more oil to be dripping down the cam housing, rather than the chain case. I'd also be surprised you would get that much oil in a couple minutes coming past the rocker shaft.

[Jeff Higgins]

Originally Posted by proporsche

Jeff..some people as the OP do not know how to set the cam timing or has the tools..If you are careful it can be done...For me, i always check the timing,the tools are not that cheap ,since you are mentioned it ..for some person who does this once in their live..

the worst adviser here;-)

Ivan

I'm sorry, that came off sounding much more harsh than I meant it to. I should choose my words more carefully. If we were standing in my (or your) garage with beers in hand, I would have said the exact same thing, but with a smirk on my face that would have hopefully indicated I was as much yanking your chain as anything else. So, my apologies - I didn't mean it quite like I typed it.

Anyway, it would haunt me no end, not checking. Like I said, it worked for me - on half of them. That, and the "Z" block plus dial indicator add up to about $200.00 from our host (I was stunned to see how much they get for that simple little "Z" block these days, every bit as much as the dial indicator itself). To me, that is "cheap" insurance. He has to buy all of the other tools anyway.

This is one of those skills worth learning. I know it's one of those supposedly "black art" skills to many, but everyone I've taught was surprised at just how easy it is. Sure, it helps to have someone to walk you through it, but once "the light comes on", everyone wonders what they were afraid of.

As far as PeteKz's comment, I would have to agree. That much oil that fast indicates the thrust plate gasket or o-ring. The camshaft bearing is pressure fed, where the rocker shaft is splash/mist oiled, with no pressure. The latter just kinda "weeps" over time, it doesn't really drip fresh looking oil at that rate.

[kevbo]

before you do anything drastic clean the area where you can, add some AC flouresent dye to your oil and buy a black light. That'll help you determine where it's coming from. It may be these two spots which may just need a good cleaning and some fresh JB weld...

[proporsche]

Jeff..it is all good...the most pita is the nut..just last year i had an engine and some schmuck put loctite on the threads ..no fun had to use torch to make very hot for removing.
For Damian ,yes it is most likely your camshaft cover and o ring..just be careful so nada moves(the cams) the best would be to get the correct tools before you start....if push come to shove we can help you with the cam timing here too...
Ivan