Technical Blog:

Oil leaks from the engine.  What's causing them, the push rod tubes, seals, or something else?   What have you done to fix them?

Thanks to Tor "speed-racer" Hansen   for suggesting this question. New! 912 Registry Members can share technical information, add technical information, and access quality, up to date technical information on our 912 Wiki.

From: Ann or Gregg Dunphy;  ; My 912E lacks its thermal reactors; nevertheless, it leaked oil as though there was a hole in the case when I bought it in 1991. I replaced the pushrod tube seals with green (non-viton) seals which lasted for about 85,000 miles. To my chagrin, I learned about the virtues of viton about a week after I'd done the job. I replaced the oil cooler seals at the same time. The oil cooler seals are still good and I just  recently replaced the pushrod tubes (I robbed my overhaul parts bin and yeh, I know I'm lazy but they look so nice and they're clean!) and seals at 100,000 miles. Yes, I did let it leak severly for 15,000 miles. I'm lazy, remember? This time I used viton seals. They seemed more difficult to seat than the green ones; I pinched an inner one during installation. To my delight, 9126001592 is no longer leaking any detectible amount of oil and, after I wached teh engine off, it no longer reaks of hot or burning oil after a drive. I'm sure the flywheel seal must be seeping a little, but I never notice it. Now, my driveway looks like I sold the car- which is something that won't be happening anytime soon. May all your oil leaks be as curable as mine were.
Gregg Dunphy

From: Joe Carlin;  ; When I first bought my 1968 912 it had leaking oil return tubes,(push rod tubes). I got some prices for the job at 3 different auto shops, they ranged from $1,100.00 to $1,300.00 to do the job. The price was very high because they said they had to pull the heads to replace them. I asked around, "how can I replace these $1.97 tubes without spending $900-$1100 in labor?".
Answer: Expanding tubes.
Checked around. Expanding tubes good or bad?
Bad, if you get the spring kind, the spring will some day loose tension, can be bumped(hard bump) loose.
Good, if you get the screw out type.They can be adjusted year after year."You only have to spend the money once" ,they will last the life of the car.  They cost 25 times as much as the orginal tubes,but the labor is a 1/3rd of the labor cost.
They are 3 times as much as the spring type,but they will never wear out. If you do this 4&1/2hr. job yourself, or pay someone $400.00 to do the job. you will relize it is something you don't want to do again.  I highly recommend them,two years oil tube leak free.  Joe Carlin 68' 912

From: philandmimi;  ;Hello. I have found the solution for eliminating leaks from the valve cover gaskets....get gaskets from Vic Skirmants at 356 Enterprises (810-575-9544).  Skirmants' sells a Fel-Pro steel core valve cover gasket that does not leak! Since there is a steel core these gaskets fit perfectly, do not require adhesive and are reusable many, many times. This is one of the cheapest and best things I have done to my car. I think they go for $15/pair. Another leak area is at the oil strainer. The flange area on the sump plate is often not flat. The problem is a result of over tightening which causes bumps around all the bolt holes. By placing the sump plate on a concrete floor, magnet side up, place the round end of a ball peen hammer on the raised bump and then strike it with another hammer. This should quickly restore the sump plate to a flat condition which will now allow the gaskets to obtain even compression.( Note: This last fix was found in the book "356 Porsche, Technical and Restoration Guide".) Harry Pellow's also says that the sump plate bolts should be tightened by starting with the inner bolts and working outward. He claims it is very important to slowly increment the torque on these bolts, going through the tightening sequence many times until the bolts are fully tightened. I have also discovered that these bolts need to be re-torqued after new gaskets are installed as the gaskets will take a
compression set. Good luck with stopping (minimizing) those oil leaks!
Phil Trenholme

From: DAVID LOVATO;  ;
What do you call a Porsche that doesn't leak oil?
A Porsche with no oil in it!!!

That's the answer I got to the many enquiries I had posted to the P-Fans list (before the dawn of the 912 Registry!!  Yah...I had a pretty constant leak of oil from the pushrod tube seal area dripping down onto my notorious thermal reactors, and requiring a good 'bottom wipe' before setting out on a drive, or else the car'd be smoking more than I do!!
Eventually I was drawn into the "the tube seals always leak" and the "use the brown seals, not the green ones" and the "synthetic oil is too thin and so leaks out" discussions that seemed to rage on the 914 pages about the Type-4 motors.   I plumped for the tube seals most recommended and gritted my
teeth for a motor-drop in order to have the seals replaced.  That was at 72,000 miles and today (with a broken clutch cable last week!!! Grief!) with 95,000 miles up we enjoy 'tube seal integrity' or at least so far!!
As far as oil leaks in general go-  I consider a decent leak an advantage on my old Mercedes Turbo Diesel, since this means that I tend to put fresh oil in it once in  a while!!!!

With thanks for all your hard work in support of our cars and this great site,

R/Dave Lovato  Sept '75 912E  9126000496...currently skulking in the garage pending it's clutch cable replacement!

From: Peter Baldauf; ; Oil leaks?  Wasn't that a factory option?  The only leaks I am currently experiencing is from the valve covers.   Ever since my last valve adj. they must not have seated properly.  (no I do not change them every time the covers come off).  I thought only 911's could lift the front off the ground. :-)

From: Jason Terada;  ; The main seal on my engine appears to have caused the most grief when it comes to oil leaks. Replacing it means dropping the engine and pulling off the flywheel to get at the seal. It also usually means a clutch job, as the pressure plate is often oiled-up from the leakage. It's amazing how much oil can get past this seal when it's bad.
I haven't had much trouble with leaky pushrod tubes. 

From: Kanas, Jon B;  ; Oil leak from oil strainer retaining bolts after car has been sitting several months in storage.  Resolved by ALWAYS replacing 10mm Nylock nuts with new nuts, and applying small amount of Permatex #2 gasket sealant to the stud threads upon reassembly.  Note:  I only pull the strainer on every third oil change, which is about once every three years.
Valve Covers:  Leak from lower front (as in front of car) corner.  Check flat lip of valve cover which seats against the head with a metal straightedge.  Gentle "rebending" of edge using small vice solved problem. It appears that the spring clips eventually cause the lip to deform, and not seal properly.   Note:  I have encountered the same problem on 36HP VW and on a 914.
Otherwise leak-free since rebuild in 1992!!!
Jon Kanas
1969 912/5 Coupe
http://www.qadas.com/~kanas/images/912/912.jpg

From: Johnflacey;  ; Used to, from the push rod tubes.   Rebuild took care of it, so not any more.

From: Helen Rebera;  ; Having steamed cleaned my '69 engine to locate a persistent oil leak which only occurs on long trips at approx 4000 revs when he's good and hot, its still not clear where the oil is coming from.
Had a Krypton Tune up yesterday and the mechanic very pleasingly said that he was impressed with the engine. 'And the oil leak ?' I asked. 'Well,' he said, 'its thirty years old, all cars of that age will lose
some oil, by todays standards it seems excessive but what you're doing is regularly topping up and effectively there's good clean oil going thru.
Seems perfectly sensible to me. And no Blue smoke which is also v.pleasing.
Any ideas appreciated though.
Helen

From: brian reynolds; ; Rick once again thanks for such a great web site, i enjoy looking 912 registry up.  Have had my share of oil leak problems with my car ,now has 58000 miles on it.Have spent a good deal of money to mechanics to have repaired.Now  i find i have a new problem and hope its just a top end problem.My advice to other owners would be , If they are not mechincs learn to live with it,and make a weekly clean up on engine and oil levels. Many of the shops i have dealt with say what do you expect for a 23 year old car. So since i have gone the normal attitude of just fix this problem ,and repair the next when it comes, i would recomend to have the entire engine rebuilt all at once. It is much cheaper , trust me on this.  brian reynolds

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