M20 Oil level sensor O-ring. Failed after 500 miles.

[Melon]

I went out to the garage and noticed a large pool of oil, about 8" in diameter under the oil pan. I jacked up the car on the passenger side, and oil started pouring out of the oil level sensor.

The car only has 450 miles on it since I resotred it, while the sensor is used, the o-ring is brand new.

Now, before I install a new o-ring, and due to the scope of the failure, I'm wondering if this is a common problem, if I installed something wrong, of if this is just a one-off fluke.

[digger]

What happened? Did it tear or something?

[zaq123]

What happened? Did it tear or something?

it's hard to tear that o-ring, it goes into the grove in the sensor. Did you pinch it or something? Look at the o-ring, what story does it tell, if any?

I personally like using Dow Corning Molykote 55 Oring Grease. It swells up the o-ring a little once installed.

[Melon]

I just have the car parked, I'll drain the oil and replace it this coming weekend.

I'm wondering if something inside the sensor let go, and it began leaking through the housing.

[Melon]

I personally like using Dow Corning Molykote 55 Oring Grease. It swells up the o-ring a little once installed.

Thanks, I'll pick some up.

[Melon]

Fixed!

When I swapped the hardware from the old oil pan to the new, I put the washer and nut on each post for the oil level sensor. Well, I only took off the nut, so there was a washer there spacing it out. I guess after a few heat cycles the o-ring shrank and voila. Going to reinstall with a new o-ring, and no washers this time.

[digger]

I used to not worry about o-ring brands but now I do. I'm sure there are some brands using the wrong type of rubber.

[dnguyen1963]

Not all rubber o-ring is compatible with oil. Get the correct one.

[Melon]

Not all rubber o-ring is compatible with oil. Get the correct one.

Yup, there was nothing wrong with the one that was on there. I did replace it with the correct CRP part.