Best guess on this oil leak?

[Shuie]

Knowing I was going to be gone all last week, I took the car out and beat on it a little bit last Saturday. The wife had called Tuesday and told me the car was leaking worse than it normally does. Got home Friday night, opened the garage door, and saw this:





Putting the car up on jack stands, I can see that it’s dripping from the rear of the cam tower/head area near the oil cooler and right above the RHS heat exchanger (circled in the pic below). The valve cover/cam tower seal look ok. Oil return tubes are dry also.



What do you guys think? Pulled stud(s)? Rocker shaft backed out? I’m gone again all this week, but I’m going to pull the valve cover and get into this next Friday. Any educated guesses as to where to start looking or what to do while I’m in there are appreciated.

Engine is a stock 2.4, BTW.

TIA

[1973911s]

How did the oil get on the cover like that? Did it come down the exhaust pipe?

Michael

[Shuie]

no, the cover was on the ground. I pulled it up for the pics and draped it over the pipes until I could wipe up the slick under the car.

[Zeke]

Wow! Sherman, I can't give much of an opinion on that, but it's not a leak, it's a hemorage! I'm sorry to see that. One thing, while you were driving, a lot of oil accumulated towards the rear and on the muffler, which in turn, soiled your cover. Mine does this to a certain extent. My leak(s) are from the VC's.

Sorry, didn't see your explanation above before I typed this.

[k9handler]

pulled stud would be my guess, or a break in the gasket.

[Jim Sims]

What was your oil level? Did you execute high-G turns to the right during the hard running? Check the oil breather hoses and the bottom of the air cleaner housing. Jim

[Shuie]

My first thought when I saw this was this was that it must have been spewing oil when I was driving and that I could have run the car out of oil. I do remember checking the oil on the last drive though. Oil level was a little low, but not alarming to me. It was still between the lines on the stick but close to the low line. There is oil in the tank now, but Im real happy these cars hold 10+ quarts. I thought I was beginning to see increased oil consumption lately, I guess it just got a lot worse.

Hard cornering? Yeah, maybe a little. I’m not a real skilled driver, though. It’s not like I can drive the wheels off the car or anything. I try to keep the car in its power band, but pucker factor cornering for me happens at much lower speeds than it does for most people here.

[Jim Sims]

I seem to recall that the 72's only held a little over 8.5 quarts (oil drained at an oil/oil filter change) so if you have 10 plus quarts in it that could be part of the problem. How were you checking the oil level - dipstick, warm, idling, on the level? Hard running can heat and expand the volume of the oil; then that combined with with a quick turn to the right (I'm not talking about a wheels off the ground or a slide but just a fast, tight radius turn) can slosh oil into the breather lines. If said lines are loose or leaking they can dump oil onto the top of the engine where it will run down and leak. One of the breather lines connects to the air cleaner housing and oil splashed there can pool in the bottom of the air cleaner and slowly leak out a drain line/valve. The drain line/valve is supposed to hang off the front of the engine sheet metal near the starter and drain to the ground however many are no longer in place or the hoses have come loose. Therefore the oil drains onto the top of the engine and goes many places before finding a route to the ground. Jim

[TerryH]

My best guess is the Exxon Valdez is parked under that tarp! Did I win anything?

Sorry, never seen oil actually running in rivers like that. Looks like black crude too. Sure the Valdez wasn't there?

[pwd72s]

Jim's right...I use 8 1/2 quarts when doing an oil/filter change. If you have a factory front cooler, some oil remains when you change. My "technical specifications" book lists the 1972 911T and 911E as having an engine oil capacity of 8 liters, the 911S (oil radiator style cooler standard equipment) at 9 liters. That's 8.45 U.S. quarts or 9.51 U.S. quarts respectively. All that said, a female dog of a leak! Hope it's only a blown gasket or seal....

[Early_S_Man]

Sherman,

Looks to me like you need to change the oil cooler seals ... my best SWAG is that the large lower one -- supply line to the oil pressure pump is split ... it is under constant pressure from the oil in the tank, and that explains why it leaks when the engine isn't running -- a 'classic' case of a static leak!

If you wish to test my theory ... drain the oil from the tank, and I'll bet the leak vanishes!

Good luck!

[DonDavis]

I agree with Warren and was about to suggest the same thing. If the cooler o ring is bad, will the engine need to be partially removed for replacement?
I suppose if I were going to do this I would go ahead with a complete engine drop and do some other clean/inspect/repair.

[pwd72s]

If Warren's right here, and he usually is, I'm crying a bit for you. 1972 shrouds don't have the removable piece to access a cooler bolt that the '73 models do. Once the cooler is removed, I'd suggest you have it pressure tested and given an ultrasonic cleaning. This a tip I learned after talking with Jeff a ROTHSPORT...he told me he'd refuse to install a used cooler that hasn't had this done. He says it runs around $80....cheap insurance, considering the labor involved. How did I learn this? I have a used cooler in my garage, eventual destination will be to Evren in Istanbul. It will have been ultrasonically cleaned & pressure tested before it heads there. (edit) On the plus side, I'm thinking you'll enjoy cooler running after the cooler has been cleaned. The years of krud build-up creates an insulating material.

[Shuie]

Thanks guys! I wasn’t thinking of the cooler seals. I'll check those ASAP.

I did a little searching for 'cam tower oil leak' and found a few old posts about rocker shafts backing out of the housings. That scared me enough to convince me to go ahead and pull the valve cover for a look anyway. I can check for pulled studs then also.

The '10+ quart' comment came out wrong. Synaptic misfire, sorry about that. No front mounted cooler for me.....yet. Oil change for me is 8 quarts in the tank and then another .5-.75 quarts to top off once the car is warm, running, and sitting on level ground. I've screwed up an oil change before, but not this time.

The top of the engine is greasy and dirty but dry. Airbox is dry. Hoses are all dry except for the hi-pressure hose at the fitting, but it sits forward of where the oil was dripping and its not leaking bad at all.

I have a cleaned and tested oil cooler for my other motor. I found a local radiator shop to do it for $40. If I have to drop this engine, its probably staying dropped until that motor is ready to go in the car.

[pwd72s]

Sherman, according to Jeff, a radiator shop is NOT where you want to take an oil cooler...their hot tank isn't the same as ultrasonic cleaning, and most of them aren't equipped to test the pressures required for an oil cooler. Again, according to Jeff, the ulrasonic cleaning is able to even remove nasty bits from a blown engine. Why do I trust him as a source so much? Alec Job does...Aside from managing his own shop, Jeff crew chiefs in the American Lemans series...