Alarming Puddle of Oil After a Long Drive

[Augurean]

Just moved from San Diego to Santa Cruz, CA. After a 500 mile drive, I parked the car on a steep driveway. The next morning when I moved the car, there was a large puddle of oil (looked like about 1/3 to 1/2 of a quart) under the middle of where the car used to be.

Looked under the car and saw a very small bit of oil on the metal just in front of the rear wheels in the middle of the car, but it wasn't dripping any more.

I changed the oil a month ago, and the oil looked really clean, so I'm guessing it's engine oil. It's not dripping now, but whether that's because it's on a flat surface, is no longer warm, etc..., who's to say?

Any ideas on where to start looking? I checked the engine oil and it looks like it's a bit low now, but isn't bone dry. I also didn't see any oil immediately visible in the engine compartment.

[AOW162435]

Transmission oil?


Andreas

[Augurean]

I'm pretty sure it's engine oil, it was very clean and amber colored. Though a friend seemed to think it smelled like transmission oil.

I should also mention it's a 1990 C4 with a manual transmission.

[aigel]

1/2 a quart will leave a huge spot, at least a foot in diameter. You should pour half a quart in your driveway to test this. . So, what I am saying is that the leak may not be as big as you think.

Which direction did you park it? Facing up hill (with the front of the car), or down hill? This is important.

Time to take off all the underbody trays and see where it may be coming from. Otherwise this is all just guesswork.

That said, if it is gear oil, it will have a foul smell to it. See if you can gauge the smell after you put some of it on your fingers. You may cross check the smell to that of oil off the dipstick.

George

[bazar01]

It's hard to diagnose oil leaks without actually seeing the car.

It is best to replicate the condition. Take out the engine under cover, clean the engine area around the leak spot, top up the oil level, then park the car in the same spot and watch where the oil is dripping from.

[Augurean]

Originally Posted by aigel

1/2 a quart will leave a huge spot, at least a foot in diameter.

Yeah...it was about 1/2 a foot wide x 2 feet long and pretty thick (slowly running down the hill). Hence the worry Had to cover it with sand so nobody would slip on it. The car was parked facing uphill.

Hard to diagnose without seeing it, but taking off the underbody trays and trying to replicating it seems like the next step. I'll also try comparing the smell to that of the dipstick...hadn't thought of that. It seems like engine oil to me, but my friend seems to think it smells too strong for that.

Any known weak spots under there (as far as oil leaking) that I should look for?

[aigel]

Which way were you facing?

The rear main seal and trans input shaft seals are generally suspects if you park on an incline and suddenly get a leak. My neighbor always parks his van facing up hill (transmission input shaft seal is leaking!)

George

[Augurean]

It was facing uphill.

I'll make note to look there, plan on getting it in the garage tomorrow. Thanks!