Mystery Oil Leak

[Aeterna]

Ive had numerous leaks fixed including the rear main, oil pan, timing cover, and valve covers. This little nugget showed up the other day. It appears the oil is coming between the plastic cover and the bell housing.

has anyone seen this one before?

 

[ddann19]

i just noticed one in mine today also. Coming down from above the filter but can’t tell where from.

 

[JonnyTahoe]

I have cardboard under mine.

 

[alpha_omega]

i just noticed one in mine today also. Coming down from above the filter but can’t tell where from.

View attachment 261406

Do you change your own oil? If not, reach up there and tighten that filter. My father in law takes his Denali to the stealership for oil changes. One day I noticed his brand new Denali with a fresh oil change was leaking in my driveway. Upon further inspection that filter wasn’t “hand tight”...more like “limp wristed”. I took a paint pen to the filter and drain plug, so when he made them fix the problem (new oil and filter), it was nice to see they actually did the work rather than saying “yep good as new!”.
Anyways, that could be a possibility regarding your leak. The other culprit would be the oil cooler lines. They are not the most exciting task to get involved in, more tedious than anything. Let us know what you guys find out.

 

[jz57]

Check oil cooler line block.

i just noticed one in mine today also. Coming down from above the filter but can’t tell where from.

View attachment 261406

 

[14RamHemiSport]

Do you change your own oil? If not, reach up there and tighten that filter. My father in law takes his Denali to the stealership for oil changes. One day I noticed his brand new Denali with a fresh oil change was leaking in my driveway. Upon further inspection that filter wasn’t “hand tight”...more like “limp wristed”. I took a paint pen to the filter and drain plug, so when he made them fix the problem (new oil and filter), it was nice to see they actually did the work rather than saying “yep good as new!”.
Anyways, that could be a possibility regarding your leak. The other culprit would be the oil cooler lines. They are not the most exciting task to get involved in, more tedious than anything. Let us know what you guys find out.

Second this. I have had a slow leak since i bought my 09 denali. A few weeks ago i went under and wiped everything down to start chipping away at small things. I need to replace the block off plate gasket and go from there. well i went under this weekend and there was oil everywhere. My first thought was "wow, this surely progressed, time to get it to the garage". Something kept telling me to check the filter. As you guys know you cant get your whole had around the filter with the pan in the way, but i was able to turn it with my fingers a good amount. This is relatively new as well (filter being loose). Im about 400 miles before needing to do an oil change, so something recently loosened that filter up. Could it be the cold temps? I use wix xp filters. never had an issue last oil cycle with the same wix xp filter. Both times dealer changed oil (i supplied oil and filter). I will be doing my own oil changes here on out, so no loose filters again.

 

[JonnyTahoe]

Ive had numerous leaks fixed including the rear main, oil pan, timing cover, and valve covers. This little nugget showed up the other day. It appears the oil is coming between the plastic cover and the bell housing.

has anyone seen this one before?

View attachment 261396 View attachment 261397 View attachment 261396 View attachment 261397

That's not even a leak. Its one tiny drop.

 

[bfonz91]

Yeah the tahoes right off the assembly line leak more than that!

 

[89Suburban]

Could also be the valley cover gasket starting to leak out the back.

 

[Aeterna]

Could also be the valley cover gasket starting to leak out the back.

thanks for the tip, ill see about trying to check that.

I agree, its a super minor leak. Honestly I have yet to see it drop on the ground. I am trying to just count my blessings and keep driving this ole girl. Currently at 188k and hoping to get another two years of solid use out of her before retiring it to a toy/hauler.

 

[Jason in DLH]

As mentioned previously it may be the oil cooler block off gasket which is directly above the oil filter (oil filter is the object on top of the photo). You can see mine had a slight leak...

This is what the gasket looks like...

But it might be something else...just throwing ideas at ya!

Reminds me...I have to check to see if the new FelPro gasket stopped the leak.

 

[Jason in DLH]

Oops...sorry...I responded to ddan19.

I’ve actually got the same leak as well (except mines a bit worse), so I’ll be watching this post as I can’t figure out where it’s coming from either!

 

[jz57]

On the oil cooler line block, there is a plug on its side. Using a 3/8 Allen wrench remove the plug, replace that plug's O-ring, you are good to go.

 

[14RamHemiSport]

On the oil cooler line block, there is a plug on its side. Using a 3/8 Allen wrench remove the plug, replace that plug's O-ring, you are good to go.


View attachment 264798
View attachment 264797

How much oil will come out of there while replacing o ring?

 

[jz57]

Very little.

 

[89Suburban]

As mentioned previously it may be the oil cooler block off gasket which is directly above the oil filter (oil filter is the object on top of the photo). You can see mine had a slight leak...

View attachment 264792

This is what the gasket looks like...
View attachment 264793

But it might be something else...just throwing ideas at ya!

Reminds me...I have to check to see if the new FelPro gasket stopped the leak.

That looks like a ***** to change, any tips?

On the oil cooler line block, there is a plug on its side. Using a 3/8 Allen wrench remove the plug, replace that plug's O-ring, you are good to go.


View attachment 264798
View attachment 264797

Where is this located at?

 

[Geotrash]

That looks like a ***** to change, any tips?

Where is this located at?

It's the same location as the block-off plate is - just above the oil filter. The difference is that those with a block off plate don't have an oil cooler so they don't have the lines coming out of it. It's not hard to access. Looks worse than it is. Helps to have the front end raise on ramps or jack stands though.

 

[Jason in DLH]

With a 24” extension and swivel joint you don’t even have to remove the tire or the inner fender liner. I did have the vehicle on jacks as I was working on something else. Super easy.

 

[JonnyTahoe]

thanks for the tip, ill see about trying to check that.

I agree, its a super minor leak. Honestly I have yet to see it drop on the ground. I am trying to just count my blessings and keep driving this ole girl. Currently at 188k and hoping to get another two years of solid use out of her before retiring it to a toy/hauler.

Who ever fixed your previous leaks did a great job.

 

[89Suburban]

With a 24” extension and swivel joint you don’t even have to remove the tire or the inner fender liner. I did have the vehicle on jacks as I was working on something else. Super easy.

Is that a 10mm?