Just installed engine...now it leaks!!!
 

I just finished running the 20 minute run @ 2K RPM only to find this leak running down between cylinders 2/3. It looks like the leak must be somewhere above cylinder 3, running down both side of the barrel. It wasn't there at first, it took approximately 5 minutes before the leak reared its ugly head. I drained the oil and changed the filter after it had cooled sufficiently. Added fresh filter and oil. Started it up...a few minutes later, the leak started. The drop(2 actually) appears approximately every 15 seconds. I would really appreciate any ideas from all of you experienced builders out there. TIA
Pic of underside cylinders 1-3 below. I fear the worst...the cam tower.

http://forums.pelicanparts.com/uploads/930leak 001.jpg

Could be from the cylinder/spigot joint or from anything above (oil pressure sender, thermostat). An oil leak at the cam housing will be evident at the cylinder head/cam housing joint. Check the easy stuff before disassembling the engine.

Did you or your builder equalize cylinder heights before assembly?

Sherwood Lee
http://members.rennlist.org/911pcars

Sherwood,
I am using the original cylinders in their original positions. The oil thermostat, temperature sender area is dry. Can the case thru-bolt seals cause this problem? If so, can they be serviced without removing the cylinder bores? Thanks.

there is really nothing that would leak oil above 2 and 3. clean if off with brake kleen, let it dry, and get under the area with a flashlight when it's running, and see where it originates. the oil switch, t/stat, and breather hose leak down the other side if they're bad. the thru bolt seals could certainly have been damaged. that's a teardown to the case to fix, unfortunately.

John,
I did as you suggested earlier today and it is difficult to determine it's origin since the cylinder air baffles block my view.

well, you could bend them out of the way. you kind of have to if they're in the way. upper thru bolts can be seen thru the alternator/fan housing hole, after it's been moved out of the way.

Can the thru-bolt be removed to replace the inner seal without removing the cylinders?

I don't think that the thru bolts can be easily removed and replaced with the engine in the car...

Draw an arrow on that pic showing the leak?

-Wayne

I have rebuilt over 50 engines before I did a 911, the ONLY one that ever leaked for me. These things are a real pice of whatever when it comes to oil leaks. I recently just tore down a 911T, all the way, just to fix the oil leaks. No problems with the case halfs. Just the cam covers, valve covers, cam towers, oil vent seals, whatever. I put the thing back togaher with 574 for the case halves, but I added a thing coat of silicone to everything else, and used silicone valve cover gaskets. No leaks now.

Dave,
Is the leak is only on the left side of the engine, the side that has the nuts on the thru bolts? If so, maybe you don't have to completely tear the motor down.
I forgot to install the air deflectors on an engine before I bolted on the cam towers once (OK, maybe more than once! :rolleyes: ). To salvage the situation, I unbolted the head bolts and the bolts holding the chain box to the engine. I was then able to pull things apart far enough that I could remove the oil return tubes and install the air deflectors. In your case, you will need to make sure the pistons don't come out of their cylinders when you do this.
Call me if you need some thru bolt O-rings.
-Chris

[QUOTE]Originally posted by snowman
..... I added a thing coat of silicone to everything else....

MORE BAD ADVICE.

Your motor will be a mess when the "thing" coat of silicone comes unstuck and finds it's way into every orifice in the motor.

I just did my first 911 motor too. I followed the advice of a couple of professionals, along with the info contained in the Factory manuals. My motor does not leak.

If you would have built your 911 motor with care using accepted Porsche methods, you would have had no leaks at all. They are different than Fords. You seem to have yet to learn that.

I don't know how "BAD" this advise really is. I know a couple of Professional Porsch Mechanics that use nothing other than silicone and they have to guarentee their work.

The trouble with some older Mag cases seems to be they are no longer straight, anywhere. THerefore the original gaskets will not seal properly, no matter what you do. I even had the heads resurfaced for sealing purposes and it sitll leaked because when I bolted everything down it deformed just enough.

If you are careful and diligent with the silicone it WILL NOT get everywhere and clog up everything. Been there done that and so far NO problems.

"Doug Zielke

I just did my first 911 motor too. I followed the advice of a couple of professionals, along with the info contained in the Factory manuals. My motor does not leak. "

Lets look at the MISINFORMATION here. First Porsche Factory Produced cars, the older ones, 1965 thru 198? all had one common problem, THEY ALL LEAK!! So logically you are saying, if I do every thing exactly like the factory did, my engine will not leak? How do you reconcile this with the facts? If you do them the way the factory did THEY WILL LEAK! How do you explain the turbo valve cover requirement, the fact that silicone valve cover gaskets are almost a necessity, the differen't types of gaskets, green, grey, whatever.

YOU sir are presenting misinformation if you say that if you do it like Porsche did ,it will not leak.

As to silicone. It can be trouble, but only if misapplied. are you saying everyone reading this forum is to stupid to follow directions and observe cautions? If you are careful silicone is the BEST sealant. Its reputaition for clogging stuff up is due to ham handed idiots mis using it.

HOw do you explain why the top auto manufacturer in the WORLD is using nothing but silicone to seal everything? Its not just less expensive, its better!

Even a numbskull can use a preformed gasket, but I would suspect that the Porsche crowd is a step above and could observe some simple precautions in the use of silicone and not allow a bunch of it to fall off and clog up everything. Maybe you do not think so but I do.

You don't read very well do you?
I said I did everything by the book, and my motor does not leak.

You always seem to know better than anyone else on this Board, so go ahead and use all the silicone you can find. I could care less.

It will tomorrow.

no sense argueing with jack, he's never wrong and will continue a thread into oblivion to try to prove his point. the engine forum has turned more argumentative than informative lately, mostly because of this.

Mr. Snowman, The factory engineers had more important things on their minds than the possibility of oil leaks years into the future, such as the way that an extremely tiny particle of silicone crap will find its way into a cam squirter line and block a hole. Even if it only blocks it for a minute or two at 7000 rpm in a race, goodbye cam lobe.

You think that you can build better motors than the factory? What are your racing credentials, vs. theirs? Endurance racing-wise? And BTW, they don't "all leak". That is what people who build lousy motors say. :cool:

Wayne,
Sorry, I just realized you had posted a question to me. The pic below illustrates the leak. The blue lines show the paths and the arrows show the lowest point of their paths before they let go...:D
It originates somewhere between the air baffles on cylinders 2&3. I removed the alternator to peer into the shroud, but it showed nothing. I could not see beyond half of cylinder barrel 2.
So I am in the dropping the engine once again so the shroud can be removed to see if the leak is coming from the top thru-bolt seals.
http://forums.pelicanparts.com/uploads/930leak 002.jpg

I don't think anyone used silicone when these engines were designed. I have used it in my race engines and street engines (only when the std gaskets do not seal well) and never had a piece of it clog anything because I am careful on how I use it.

So in response how do you explain all oil spots under all the factory done Porsches (the pre 198? ones)? I even remember seeing a couple leaking on the showroom floor, about 1969-70, not years into the future.

Seems to me that two or three people are in the constant "attack" mode. Even when I post something reasonable, and using silicone is reasonable, widespread, and used by real Porsche mechanics all of the time. Its use, on certain o rings, is even suggested in Wanes book. I am guarenteed a response starting with something like MISINFORMSTION or another form of personal attack. Could it be they respondants are incapable of generating a valid technical response on the merits of the topic? A responsible response may have been something like the following:

Silicone has been responsible for clogging many engines. Because of this I do not use it for anything. Here is how I fix an engine with std gaskets and keep it from leaking. blah, blah, blah. Or in extreem cases purchasing special aircraft grade solid silicone gaskets or whatever. But instead I get

"MORE BAD ADVICE."
blah blah blah

I have refrained from responding in this way, except for the last couple of days, where I turned it around a couple of times, and thats to make a point very clear. That it is not nice to start out a topic with a personal attack. Point seems to have been made.

I do like DISCUSSION which is an entire different matter. Differen't points of view can be discussed without personal attacks. Generally speaking personal attacks are generated by those who lack the ability to discuss things based on merit. Take DEMOCRATS for example when they discuss our Pres.

The only things that could be leaking from that area are:

- Through-bolt holes
- Cylinder base gasket

It's a 930 case, so it's unlikely that the cylinder spigots are off. Also, the cylinders are not known to leak heavily. I would suspect the through-bolt holes. Did you use black silicone on them (as I recommend?).

Note:the black silicone in this case is on the outside, and is external to the engine, with very little possibility of making it inside. I prefer to use a bit of Curil-T on gaskets that I think may leak in the future.

-Wayne

Maybe someone can explain how theres a difference between silicone, non hardening or hardening permatek, or curil T. Any of these can clog a squirter if it gets in the wrong place. Any of these can break off in a gob. The reason they do not become a problem is that the people who use them are carefull. Some are not and so the bad rap.

Make that 4
 

Please tell me WHAT is "reasonable" about concluding that 911 motors are POS (for oil leaks) from a study of ONE (which you admitedly rebuilt. . .that leaked)

The reason people are "attacking" you, is because they don't look forward to the task of re-educating those whom have read, and picked up some "jackism" from one of your half-baked posts.

When a newbie comes to Pelican, seeking info about a 911 rebuild, they certainly do not want to wade thru a bunch of missleading posts.

The thing is, Snow, You come across with a confident maner, touting vast experience. Though, what you're not posting (enough about) is your lack of 911 engine rebuild experience.

Hey, an idea; go work for Motor-Mister (you know; "well known, high volume, 911 motor rebuilder") . . .I think that with their special set-up; you could apply some of your special processes, an have a real meeting of the minds.
:cool: just think of the damage you could do here, with all that 911 experience.http://www.pelicanparts.com/support/smileys/eek3.gif

this post made possible by a contribution from the Special Olympics Organization.

I think that Jack has a wealth of useful information and can be a positive contributor to this board. However, I also feel that his experience in the Chevy world is a handicap - somethings are just different here. You goop up a Chevy motor with silicone - standard practice. The 911 (and VW) engines have no gaskets on the case parting lines - they are higher precision engines.

Jack, I think you speak a bit too emphatically, stating what is your opinion, but making it sounds like facts that are carved into stone. Back off on your rhetoric, and you will fit in a bit better.

-Wayne

Well on the subject of Porsche engines and oil leaks. Indeed the first 911 ( I have rebuilt 356 engines for over 30 years) had a oil leaks, a lot of them and I tore it completely down over 3 times trying various ways to fix them, finally resorting to the old standby of goo, lots of goo. I also talked to probably over 30 people, some of which have rebuild 100's of 911 engines in the process of trying to find the source of the leaks. That helped jar my memory of looking at 911s back in the 70's which did indeed have oil leaks on the showroom floor. Porsches are NOT a POS. The leaks are really only drips, one to 5 or 6 drips a day, never ending drips, that cannot be stopped if you use original Porsche stuff.

I consider myself a good enough mechanic, that if I tear an engine down 3 times just to get the oil leaks fixed, before its ever put in a car, and cannot find a difinitive reason for the leaks, except that they all seem to do it, and people who have 100's of man years experience cannot solve the problem without silicone or something like it and I have put months of effort into finding the bottom line on the subject, I do kind of get authoritive. Sorry about that.

Actually, we have something in common. Leaks drive me crazy too, and I am about to install my rebuilt SC motor that has been sealed up using more or less the latest info on leak-proofing. It is my first 911 motor rebuild, (I've done other makes w/ good results and no leaks), but I have had some very expert help and advice+ read every book out there including Wayne's.

The reason that I say, "more or less the latest info", is that even the respected experts have individual opinions on certain procedures and chemicals/sealers.

I do believe that 911 motors do not have to leak, though. I worked at the dealer in the '80s and they definitely did not leak on the showroom floor. Not saying that this never occured, anything is possible, but w/ Porsche's obsessive quality control and testing of each car, (at least in the air-cooled days), ;) , it's a little far-fetched.

Air-cooled engines expand and contract a lot more than cast iron liquid-cooled machines, the engineering challenges and mechanical knowledge required are quite different. These motors are almost like a living, organic thing, kind of like "Furbies", if you will. We have quite a few people w/ light aircraft knowledge and experience around here, they are particularly valuable on a 911 board. Try not to get too frustrated w/ these machines, they are incredibly rewarding once mastered. Take care. :cool:

I remember this very clearly now. It was 1969 and I bought a new car that year. I looked at quite a few differen't ones. I remember the Porsche because the salesman stated that they did not keep them on the showroom floor because they leaked! They were all lined up outside, except one. They had several 911's and 912's. It was in Rochester NY or Elmira NY, I don't remember which. I did not end up buying the Porsche.

What a load of rubbish!

So I guess Max Hoffman had to hire extra staff just to clean under all the Porsches in his (indoor) Manhattan showroom??

Let's see, where were we? Oh yes, the engine leak...:rolleyes:
I removed the air baffles to inspect the top thru-bolts on cylinders 2 & 3...dry. Removed head studs to pull cylinders out sufficiently to inspect lower thru-bolt nuts...damp. Removed thru-bolt nuts to inspect sealing rings...dry. Inspected #2 cylinder spigot gasket...kinked!!! It appears that #2 gasket had shifted during assembly. That is, rotated enough that when the cylinder was pressed down, the scallops were no longer aligned with the head studs, causing the gasket to rise around the areas of the stud. This prevented the cylinder from completely sealing the spigot bore. Can't explain it... the left bank was up during assembly to minimize this type of event from happening. Maybe the spigot bore was oil damp which prevented the adheasive side of the gasket from staying put? Anybody's guess...
Anyway, thank you everyone for your suggestions. I must add that this thread had been more of a "pulpit" than a forum. I really believe that if the techs in Germany can build a 911 without leaking, I should be able to do the same. A lot of time has passed since my engine was originally assembled. Gasket sealing material has improved dramatically over that span. Still, I refuse to use "goop" that goes beyond the norms of engine assembly. The thru-bolt sealing rings did their job...I screwed up somehow on the spigot bore. Locktite 574 did its job. The cam towers are dry as are the case halves.
http://forums.pelicanparts.com/uploads/gasketleak.jpg

So, in conclusion, i guess this means that silicone is fine and not the supposed anti christ as opinioned by some on this post. Just curious since i like using the stuff on gaskets (especially cam housing gasket on 944's which can leak very easily onto the header if not torqued perfectly).

I didn't know that the cyl base gasket (as shown) had *any* adhesives on it. The ones I recently installed did not. Anyway, I coated them with a thin spray of Permatex Copper Coat for insurance. The adhesive will keep them from getting out of line as well. Wayne likes Curil-T for the same job.

Also...
"Locktite 574 did its job...."

And it's *not* a silicone.

Doug,
The top end rebuild kit came with base gaskets that were wrapped in plastic, individually mounted heavy paper. The adheasive almost feels like a tacky shellac, on one side only. I thought these things were supposed to be mounted dry.

They are supposed to be mounted dry. People use various tacky goops to hold them in place during assembly. I use a couple of pieces of masking tape.
-Chris

Thanks for that info, Werk!
I musta got riipped-off....the gaskets I bought came in gen-u-ine Porsche wrappers, but had *no* sealant of any kind on them. Slipped thru the cracks, I guess. Anyway *no* leaks there or anywhere on the 'Bomber's mill.

MISQUOTE!!! Don't quote me, unless you're 100% sure of what I said.

I recommend using the Loctite 574 on both sides of these rings as an added protection against leaking. I think that the Curil-T could be a little too thick here, where deck height and cylinder height alignment is very important.

All the cylinder base gaskets I've seen are pure copper with no sealants or adhesives on them.

-Wayne

The base gaskets I've used had some sort of coating on them. It was slightly tacky like a wax or weak adhesive. Perhaps it is just to keep protect them from corrosion?
-Chris

Where did you get the gaskets from?

-Wayne

Wayne,
It was a rebuild kit manufactured by Reinz AFM(or is it AFM Reinz?)

Wayne,
Not a quote, just a (wrong) recollection.
Don't blow a base gasket...ha, ha, ha!
Just wait 'til *you* get "Oldtimers Disease".

I wouldn't doubt it. It ain't a load of rubbish either.