Skip the auto shop - Our mechanics make house calls

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

asked by on

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Scraped a small layer off of my tire wall; should I be worried?

I would talk to the insurance company if you have full coverage with a low deductible so you can get the rim and tire replaced. If you decide to not go with the insurance route then you should at least...

Q: Can you operate safely with the trunk lid open?

Having the trunk open while the engine is running is not a wise idea, although it may be necessary in some instances. Your car’s exhaust contains carbon monoxide, which is toxic and cannot be seen or smelled. If the trunk...

Q: Transmission axle sea

You didn't mention that you had the axle replaced but if you did the new axle may be the wrong one for your car, or you may have to get the replacement axle and seal from the dealer. This vehicle...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...