Oil leak near "big pulley"

[mr_maxime]

I'm still not knowledgeable on everything but I have an oil leak that appears to be coming out of around the pulley. My oil level didn't seem bad after about 5k miles. I'm assuming it's probably a significant job to change out whatever has gone bad here.

[Chris 16409]

Check the oil pressure sender on the driver side. That's a common leak area you should rule out.

[DMC-81]

Hi there,

Yes, if it's leaking oil around the crankshaft pulley, it's a medium sized job as you most likely need to remove the belts and the exhaust for room to work. The new seal is inexpensive so it's mostly labor.

Here's the process:

After removing the parts in the way of the pulley, you probably need to lock the flywheel using a special tool. Then, remove the nut with an impact wrench and a 35mm socket:
image.jpg

After removing the nut and washer, mark the position of the woodruff key on the pulley. Then reinstall the nut just tight enough to rotate the engine to get the key in the 12 o'clock position.otherwise it may fall into the oil pan.
image.jpg

Old leaking seal:
image.jpg

I used a gear puller to remove the pulley without bending/damaging it.
image.jpg

Clean up the area and install the new seal, ensuring it is square/straight in the hole.
image.jpg

Reinstall the pulley to torque spec using loctite.
image.jpg

Good luck with the job!

[Ratrace427]

Wet spot looks to be on the driver side. Oil pressure sender.

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[DMC-81]

Wet spot looks to be on the driver side. Oil pressure sender.

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I would agree that it's good to rule out the oil pressure sender, but in my experience if that seal is leaking, the oil travels along the oil pan in front of the pulley, but with oil on the timing chain cover, especially the bolts under the seal indicate that it is the pulley seal. Maybe both are leaking. The best thing to do to avoid an unnecessary repair is to clean the area up and drive it a few miles and then check for leaks.

[DMC5180]

I would agree that it's good to rule out the oil pressure sender, but in my experience if that seal is leaking, the oil travels along the oil pan in front of the pulley, but with oil on the timing chain cover, especially the bolts under the seal indicate that it is the pulley seal. Maybe both are leaking. The best thing to do to avoid an unnecessary repair is to clean the area up and drive it a few miles and then check for leaks.

For the timing cover seal to be the source of the Wet oil along the pan seam, I would expect to see a wet oil trail running down from the seal. I don't see that present. I'm not saying the seal isn't weeping, but it's not the primary source of the wet oil. If the pressure switch is leaking it will be pretty obvious.

Oil has the ability to defy gravity and creep uphill. Case in point, look at the exhaust shield bracket. The bottom half is covered with moist oil grime.

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[DMC-81]

For the timing cover seal to be the source of the Wet oil along the pan seam, I would expect to see a wet oil trail running down from the seal. I don't see that present. I'm not saying the seal isn't weeping, but it's not the primary source of the wet oil. If the pressure switch is leaking it will be pretty obvious.

Oil has the ability to defy gravity and creep uphill. Case in point, look at the exhaust shield bracket. The bottom half is covered with moist oil grime.

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Hi Dennis. Sorry, I didn't suggest that the timing chain cover seal is suspect. I was intending to refer to the pulley seal, and the 3 wet bolts below it.

Regardless, my engine was wet all around that area. After some specific troubleshooting ( cleaning, running the engine, and inspecting), I wound up replacing the front/pulley seal, the timing chain cover seal, and the oil pressure sender seal to end up with a leak free engine. I think the hot exhaust right in front of the area doesn't help seal longevity.

It's best to clean the area and then check for leaks..as you said, the dirt helps the oil travel.

[Jonathan]

Hi there,

Yes, if it's leaking oil around the crankshaft pulley, it's a medium sized job as you most likely need to remove the belts and the exhaust for room to work. The new seal is inexpensive so it's mostly labor.

Here's the process:

After removing the parts in the way of the pulley, you probably need to lock the flywheel using a special tool. Then, remove the nut with an impact wrench and a 35mm socket:
image.jpg

After removing the nut and washer, mark the position of the woodruff key on the pulley. Then reinstall the nut just tight enough to rotate the engine to get the key in the 12 o'clock position.otherwise it may fall into the oil pan.
image.jpg

Old leaking seal:
image.jpg

I used a gear puller to remove the pulley without bending/damaging it.
image.jpg

Clean up the area and install the new seal, ensuring it is square/straight in the hole.
image.jpg

Reinstall the pulley to torque spec using loctite.
image.jpg

Good luck with the job!

Dana, you do one helluva nice job with your resto work. Wow.

This is a job I could benefit from doing, for the seal and to either replace or recondition the crankshaft pulley itself. The one you put on looks brand new. Did you find a replacement somewhere for sale or did you clean up and replate your original one? I think they are NLA from DMCH.

[DMC-81]

Dana, you do one helluva nice job with your resto work. Wow.

This is a job I could benefit from doing, for the seal and to either replace or recondition the crankshaft pulley itself. The one you put on looks brand new. Did you find a replacement somewhere for sale or did you clean up and replate your original one? I think they are NLA from DMCH.

Thanks Jonathan! It's was a labour of love. Yes, after I cleaned them up a bit, I had my old pulley, 35mm nut, the engine bolts, etc. replated in yellow zinc. As you mentioned the pulley is NLA so I was extra careful to not bend it. Reconditioning the parts was economical as just the timing plate (102762) above it is $90+ to replace.

[mr_maxime]

I'll double check where it seems to be coming from, but I changed the oil pressure sender last year. From above it goes to about halfway up the pulley on the passenger side though. It's considerably larger and more noticeable than when the pressure sender was lwaking originally.