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Q: Does a failing crank seal cause visible leaks on the driveway or garage floor in every case?

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I have been told I need to replace the crank seal. Service tech discovered a leak. I haven't noticed any leaks on the garage floor. Could this be a small leak, where there's not enough oil leaking out to be on the garage floor?

My car has 150500 miles.
My car has an automatic transmission.

A: I like to classify leaks when I see them, a...

I like to classify leaks when I see them, and I think these identifications could help in your case. I use three classes of leaks:

  • Class 1 = slight wet residue leak around area with signs of a drip forming under the leak but does not drip on floor. (Does not require repair yet and may be normal)

  • Class 2 = moderate wet leak around the area with signs of a drip forming and does drip once or twice a day. (Recommend repair when possible and is not normal)

  • Class 3 = heavy active leak around the area with signs of a drip forming and actively dripping at least 1 drop a minute. (Recommend repair now; may cause failed component)

I recommend having the same technician show you the leak and then asking about its severity. If you do not feel comfortable with that mechanic, an independent technician from YourMechanic can come to your car’s location to diagnose the potential leak for you and replace your crankshaft seal if necessary.

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