Engine-Gearbox Flange: Slight Oil Leak

Hello fellow mechanics!

Yesterday, I noticed that my car is leaking a little oil.
A drop of oil was located right at the junction between the engine and the transmission. This area houses the clutch, and the space below it is open.

Unfortunately, based on the "smell test" of the oil drip, I couldn't determine whether it was engine oil or transmission oil (although transmission oil smells very different).
The amount of oil leaking is very small. Therefore, I suspect the radial shaft seal on the transmission side. In my opinion, the seal on the engine side should leak significantly more oil, as the lubricant there has a lower viscosity and is pumped under pressure to the bearing.

Are there any experiences to share here? What are your thoughts?

Regards,
Alex.

Hello Donalexo,

Based on my experience, I would lean towards the crankshaft oil seal.
"I also have a slightly oily feeling in that area, but it's not dripping."
Since nothing has changed in the last 30,000 km, and the clutch is also fine, I'll leave it as it is for now.

Best regards,
Albrecht.

Hi Alex,
My 1Z is behaving similarly to Albrecht's AFN.
With the difference being that mine has had 117,000 miles since I bought it.
Behavior has (currently approximately 197,000).
Based on its color (black), it is engine oil.
Since both the clutch and the oil consumption are within normal limits.
-> observe and otherwise ignore.


Best regards, Rudi.

@Rudi:

Quote:

Based on its color (black), it is engine oil. However, both the clutch and the oil consumption are within normal limits. -> observe and otherwise ignore.

Bei mir sind Ölverbrauch und Kupplung ebenfalls o.k. That reassures me.
However, I don't consider the color of the oil to be a particularly reliable indicator, as the oil can accumulate various contaminants (coupling debris, dust, etc.) from the leak point to the bottom edge of the flange, and ultimately always appear black.

I will monitor it regularly and refrain from taking any action for now. Thank you for your responses.

Regards,
Alex.

Based on experience, the crankshaft oil seal...

Just wait until the clutch starts to slip, because everything will have to be taken apart anyway .

If it were an old Kadett-D, you could quickly check it. But the ingenious principle is unfortunately out-of-order .

CU Gremlin.

Hello,
My car has been losing oil for about 50,000 km, and the oil pan is also very dirty, so I haven't been able to pinpoint the exact location of the leak. However, only a few drops appear in the area between the engine and the transmission after the winter break. Unfortunately, the clutch is jerking, but it's not slipping yet.

Regards,

Tobias.