I don't even know where to begin (oil leak help)

chatas17 · chatas17's Garage

Well, I took my car out on it's maiden voyage the other night and I was an easy find due to the smoke trail that the car created. There is significant oil on the cylinder barrel air deflector plates (drips). Can anyone point me in the right direction as to where the oil is coming from? There is residue on the exhaust ports but not as much as the deflector plates. I checked the front of the engine up top and that is pretty dry. This engine is suppose to have 400 miles on a rebuild. This was done several years ago. I think the car sat for a while with little use. It has the upgraded turbo valve covers, thermal reactors removed, and upgraded 11 blade fan. The car is a 911S (1975). I would greatly appreciate some advice. I'm a little bummed out at the moment. Thanks, Jim

ossiblue · 06-17-2007, 06:10 AM

Pretty hard to advise without a picture and more info but I'll go first, keep in mind I'm no expert but I also have a 75 S.

You mentioned checking the front of the engine. Did you mean the area closest to the firewall, toward the front of the car? That's where there are some notorious leak points--oil pressure switch, thermostat seal, etc. If you checked the area closest to you when standing behind the car, then that would be the rear of the engine.

Your post sounds like there is a lot of oil flowing. Is it coming from both sides of the engine? Is it coming from all cylinders, or just one? Is it leaking more toward the front of the car?

Sorry I couldn't help much, but if you can nail down where you see the leak, those with similar experiences will advise soon. Keep the faith, it's not as bad as you think.

chatas17 · chatas17's Garage

I'm charging the batteries for the camera as I type! The oil leak is on both sides of the engine. There is lot of oil flowing. I referenced the front of the engine as closest to the front of the car. Is that correct? I will post more photos. Here is one that I took the other day but it is the greatest. Thanks for the response.

ossiblue · 06-17-2007, 06:30 AM

Chatas17,

Yes, front is toward front of car. Still a bit hard to tell, but since you say it's from both sides that helps. Do you know if the the heads have been retorqued since the rebuild? Do you see leaking from between the heads and the cylinders? Are the studs loose or have you had them checked? I'm asking these questions to help you diagnose. As I stated, I am no expert but most of the leaks I'v experienced or read about on the board are localized or more severe in one part of the engine. Yours sounds like it leaks equally all over the bottom, onto the heat exchangers. Is that right? That's what makes me think it may be an assembly issue. Just my thought--don't panic. More pictures and information will get you more difinitive answers from the experts on this board.

JeffreyNMemphis · 06-17-2007, 06:32 AM

Hi Jim,

It sounds like you are leaking at the base gaskets. You would not be able to see any oil from the top of the engine, because of the fan shroud. Was the rebuild documented? Who did the work? There are many definitions of "rebuild". It might have just been resealed.

Was the smoke coming from the exhaust? Worn valve guides could be causing the smoke.

TerryH · TerryH's Garage

New owner = maiden voyage = oil leakage = exhaust smoke fogging = too much oil in motor.

The above scenerio occurs about 80% of the time with the symptoms you describe.

If the oil level is fine when checked with the motor hot and running, only then I would begin looking elsewhere. You may have to clean motor and add dye to oil.

chatas17 · chatas17's Garage

I changed the oil yesterday. Drained old oil, put 9 quarts in, drove for 15-20 minutes, checked oil, added a quart. The dipstick indicates just above the minimun. I wish it was that simple. I don't know if the heads have been retorqued. On the passenger side, there is more oil on the exhaust and three of the studs have been replaced with "allen hex bolts". There is residue on almost all of the head bolts but that looks old. The fresh oil is on the bottom. Most of the oil is on the barrel air deflector plates. There is a lot of residue on the passenger side exhaust but not so much on the driver side. There is also oil on the cam plate. It think that's a separate issue. I also notice a complete gastket set in a box that came with the car. Believe me, I think the PO was not totally disclosing the issue with the car. The valve cover gaskests don't look too wet but maybe that is part of it. I think I may replace all the gaskets I can without removing the engine. What ones are possible to replace without taking the engine out? I cleaned everything off. I will take it for another drive and photo the underside of the engine. Thanks for everone's help. I would be really bummed if I didn't have access to the board. Jim

svandamme · svandamme's Garage

oil thermostat seal?

chatas17 · chatas17's Garage

Ok...Update. I took the car for a drive. The smoke is coming from the driver side front of the engine. It comes up the top of the engine. There is also (doesnt' make sense but) oil on the passenger side exhaust under the valve cover. That is smoking a little. Is retorqueing the head studs as easy as using a torque wrench and setting it to the proper specs? The car runs at 190 and has good power with no smoking (other than the leaking).

the · 06-17-2007, 12:13 PM

it's usually the oil pressure switch on the top of the engine.

chatas17 · chatas17's Garage

Quote:

Originally posted by the
it's usually the oil pressure switch on the top of the engine.

That's what all my research is telling me but I don't really see oil up that high. Do you still think it's the switch? I wil take the CIS cover off to get a better look. Thanks

the · 06-18-2007, 08:33 AM

yeah, if the switch is leaking, it's hard to see the oil up that high. It easily disguises itself as a lower oil leak.

Take off the black CIS boot, get a mirror and a flashlight, and take a look at the switch.

Walter_Middie · Walter_Middie's Garage

Quote:

The dipstick indicates just above the minimum

Jim,

Just so that we are all on the same page here - please assure us that you checked the dip stick while the car was running, on level ground, and with it warmed up. The oil in your photo looks fresh - not like a leak that has been going on for awhile.

After dirving for 15-20 minutes, the car was probably warm.
Level ground is usually easy.
It's the engine running that usually gets the new owner - how many kinds of cars do you check the oil with the engine running?

chatas17 · chatas17's Garage

Rex,

Thanks for asking. Yes, I did check the oil with the car running after it was at temp. I only put 9 quarts first, then added 1 more quart. You are right, the oil does look fresh. What do you think about that? Could the oil leak be so severe? It's strange, the ground doesn't puddle up so much, but it does leak when it's running.

JP911 · JP911's Garage

Could this be really bad blow-by? If the rings never seated after the rebuild it could happen.

Walter_Middie · Walter_Middie's Garage

Jim,

Give us as much recent info on the car as you can. When did you buy it? Did you get to drive it before you bought it? Did a mechanic look at it (PPI)? You say the engine was just rebuilt but sat for a while. Did the PO start it again after storage or did you? Was the car transported to your location?

My first guess is that the oil was just overfilled. Someone else may have done it before you got it. It's also possible that a seal has dried out from storage - like the oil return tubes, but your picture shows they are dry. My next guess is not so easy - rocker arms. If you take the intake valve covers off (a 5 minute job) you can see there are sections where there is supposed to be oil, and sections that are just open to the outside of the engine block. If there is oil in there where no oil should be, it could be that whoever rebuilt this thing destroyed the rocker arm seals. You said you found a hex head bolt in the exhaust system where a stud is supposed to be? This is not a sign of professional mechanic.

Now that I look at you photo again, it does look like there are areas where oil has been for awhile. More pictures please - you'd be amazed at what some people can see from just a few photos.

chatas17 · chatas17's Garage

Rex, I bought the car a couple of weeks ago from someone in Washington. The PO told me that he drove the car every so often but only 400 miles in the last couple of years. I don't have any paperwork. He was suppose to send it but never did. The car was transported to me. I cleaned the bottom of the engine and within 20 minutes of driving it was wet again. The red circle is where most of the smoke was coming from (on top). I checked oil temp switch (visual) and it had some sludge but not very wet like fresh oil. Believe me, the PO took me for a ride and wasn't honest at all. Here are some more photos. She's leaking pretty good. Some oil is fresh and some is old.

ossiblue · 06-18-2007, 06:07 PM

What is that hanging down, coming from the right side, and secured by wire in pic#1 and #2? Not that it's related to the leak but what is it?

chatas17 · chatas17's Garage

I don't know.... I will check it out. I guess that's not normal?

ossiblue · 06-18-2007, 06:31 PM

Could the smoke from the top left side be coming from the oil breather housing? Could the thing hanging under the engine be the breather tube that should be connected to the housing? Just a stab but the breather is in the right location and would certainly smoke when the engine was hot. Doesn't account for the leaks which do fit the location of the pressure switch and thermostat.