Woe Is Me - Oil Leak!

Here's one more for my recent list of woes. I went into the garage today for the first time since my Friday night drive and found this oil trail behind the car.

I had already taken note of the pretty substantial leak that can be seen on the blue absorbent mat by the tire (which has gotten worse), but I was truly taken aback by the trail. Odd thing is, it seems to stop at the garage door, I can't see any in the driveway. Maybe the hot oil got absorbed into the concrete except where it's painted. Also quite a few dead leaves in the driveway.

Not sure if it's engine or transmission oil. Engine oil level is about where I remember it to be prior to the last trip. Gear oil is more of a concern as it can't be topped up.

Any ideas?
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Yo dude! has this car been in regular use or have you just started using it after a long layoff?

 

Started using it regularly 6 months or so ago after a long layoff. I just took it for a short drive, long enough for it to get thoroughly warmed up. No sign of the leak.

 

Dan, that looks kinda thin. If you don't see it on the driveway, and the level on dipstick isn't lower, maybe it is water (condensation) running off an oily engine block...maybe?

 

Definitely has some viscosity to it, but you're right, it is rather thin. Not watery, though. I thought about brake fluid, but nothing on the inside of the tire or wheel to indicate a leaky caliper. Just had the brakes thoroughly inspected and two calipers rebuilt.

I guess I could check the brake fluid level to be sure. Brakes seem to be working fine. Thanks.

 

In the pic it looks to line up with the wheel, I assume it really doesn't?

 

The center of the oil spot (as near as I can tell) is roughly even with the back of the tire's contact patch and about 9" inboard of the inner sidewall of the tire. I have one of those parking stops in the garage, so I always stop in more or less the same place.

 

check the radiator hose connection from the center tunnel of the car at the metal water pipe coming right along side the passenger gas tank. If the fluid is more vicous than water and has a light browinsh cast it could be radiator fluid (mixed with water). If it is just oil leaking check the right rear engine mount as oil pools in the head & drips down onto & into the engine mount. In fact it can pool inside the engine mount housing (right rear)and slowly leak out. good luck

 

Does the fluid have any smell to it? Glycol coolant will have a bit of a sweet smell and dissolve into a wet paper towel you put on the drips, gearbox oil may smell a bit of sulfur, and either gearbox or engine oil will not dissolve into the wet paper towel but instead sit on the surface.

Loosen the R rear wheel nuts, Jack up rear of the car, pull the wheel and fender liner, and look around. If you don't see anything coming down the right side or adjacent front and rear sides of the engine it may be one of your bottom cover plate gaskets is leaking.

 

How about a leaky right rear brake caliper piston?? A common issue.


Pietro

 

Definitely not coolant or brake fluid. Probably not engine oil. My guess is, at this point, that it's gearbox oil leaking from a driveshaft seal. I'll get it up on a lift this week to confirm.

Thanks for all the suggestions and assistance!

 

Dinodan, next to last line above "Gear oil is more of a concern as it can't be topped up" is not quite true. It can be done, but it's a pain in the butt.

Jack the car up and adjust the jack stands so the car is level.
Undo the LARGE brass nut that faces to the rear on the rear lower center of the tranny housing.
Stick your finger in the hole and you should feel the level of the fluid flush with the bottom of the opening. If it's not you need to top off.

Top off either by adding more fluid through this hole or going to the left wheel well, take off wheel, take out fender well lining and remove the smaller brass nut on top of the transfer casing.

Slowly pour your favorite gear lube into that hole until you see lube dripping into the catch pan you had placed directly under the LARGE hole previously mentioned.

You are now topped off. Let the excess drain for 5 minutes. Replace the LARGE hole nut (use a fresh washer) and the smaller nut (fresh washer, also) and you are good to go.

Good luck finding that leak. You may find that the source is the 2 rather large hoses that take oil to and from the heat exchanger in the vicinity of the oil filter. Lots of heat cycles and age tends to cause them to start weeping where they are crimped at both ends. Check it out!

Bill

 

The oil leak seems to correspond with the location of the two oil hoses leading from the engine to the oil cooler. These get hard with age and leak. Check it. Fix could be as simple as replacing the hoses. Good luck.

 

I know you said it was not coolant, and there have been other suggestions, however, it might have been some blow off from the header tank, its hot and it will carry any oil or road dirt it finds. If the cooling system was filled without bleeding it, it might give rise to a pressure build up and it will dump coolant. Check the level with the car cold .I don't know if you do your own wrenching, I would check all the items on page 37 of the owners manual. You might be well advised to tread lightly with this car, for a while at least. Treat like its new and running in, bearing in mind its not new and monitoring all that you can. Keep your eye on oil temp and don' rev more than 4k until you know the coolant system is O.K. Look for simple solutions first. blah! blah! blah!

 

I'm taking the car to my mechanic this afternoon to put it on the lift and have a look. I'll report back...

 

Thanks. As I've mentioned elsewhere, I'm taking it to the mechanic this afternoon to have a look underneath. I do baby the car pretty much, always keeping an eye on the temp gauges (though I've never known it to overheat, even in the SC summers). I never exceed 3500 - 4000 rpm until the oil thoroughly warms up, and then rarely go above 6000 in deference to the car's age. It only has 28K miles on it, but of course I'm aware that age is measured in years as well as miles. I always check the oil when the car is cold, and maintain the level at least halfway between the high and low marks on the stick. Mostly I've used Castrol GTX 20-50. Last oil change was about 6 mos. ago.

As mentioned, I'll report back on this afternoon's findings.

 

It could be something as simple as tightening fasteners or those problematic sump studs leaking.

Best wishes for a minor inconvenience

 

Small amount of engine oil leaking from the rear cylinder bank oil filler tube gasket. Small amount of gearbox oil leaking from the right-hand driveshaft seal and possibly also the gearbox pan gasket. (Hard to tell because it's dripping down from above.)

Checked the transmission oil level and it's fine. Nothing to worry about for now.