Oil Leak coming from somewhere towards the front

Trouttruckin · March 4

I’m having a tough time figuring where this oil leak is coming from. It’s pooling under the front plastic guard and splattering all the way back to the transmission pan. At first I thought it was definitely the oil pan gasket, but after I took off the plastic guard in the front to investigate, I noticed two rubber lines that connect to two aluminum lines and run back. They had oil dropplets on them, but above them were completely dry. Are these oil cooling lines? If so, are they known to crack? The weather just went from cold to warm, so maybe the temp change caused them to crack? I can’t see an obvious sign of a crack so I'm not sure. Anyone ever seen this or have any other ideas for where oil could be leaking from?

kickass audio · March 4

that's the oil cooler lines. GM makes some crap lines that love to leak on all generations. I replaced them on my 2014 and i'm sure my 2023 will need it eventually as well. If you have a 4WD truck they can be a royal pain to replace but not impossible.

Trouttruckin · March 4

1 hour ago, kickass audio said:

that's the oil cooler lines. GM makes some crap lines that love to leak on all generations. I replaced them on my 2014 and i'm sure my 2023 will need it eventually as well. If you have a 4WD truck they can be a royal pain to replace but not impossible.

I do have the 4wd. Assume these cant be replaced in sections? Likely have to replace the entire line?

davester · March 4

gm wants you to replace the whole line

some people will take the line off, cut the crimps replace the hose sections and use hose clamps or some other way to attach the hoses to the metal lines, that is more reliable than just crimps.

Trouttruckin · March 4

Here’s a video of someone else replacing the line if anyone is Interested https://youtu.be/gcRtfp5L2c8?si=bbp9xugcQr_QpTdy

Trouttruckin · March 5

for anyone wondering. this is a known issue. There's a customer satisfaction program out but the program ended in 2023. out of luck now. if the aluminum lines are still good, the quickest/easiest way to fix this is to cut and replace just the rubber hose and tighten them down with a fuel line clamp. replacing the whole assembly is a PITA and unnecessary .

clowe1243 · March 18

Replacing mine tomorrow evening for the same issue. Hell, even took a picture of them and CHATGPT told me the issue. Going to take the old ones and replace the hose with AN fittings and hose. Depending on the weather this coming winter, may need them sooner or later.

GMCustomerService · March 19

On 3/3/2026 at 8:45 PM, Trouttruckin said:

I’m having a tough time figuring where this oil leak is coming from. It’s pooling under the front plastic guard and splattering all the way back to the transmission pan. At first I thought it was definitely the oil pan gasket, but after I took off the plastic guard in the front to investigate, I noticed two rubber lines that connect to two aluminum lines and run back. They had oil dropplets on them, but above them were completely dry. Are these oil cooling lines? If so, are they known to crack? The weather just went from cold to warm, so maybe the temp change caused them to crack? I can’t see an obvious sign of a crack so I'm not sure. Anyone ever seen this or have any other ideas for where oil could be leaking from?

If you are unable to identify the source of the oil leak, it is best to take your Silverado LTZ to a Chevrolet dealership for a diagnosis. As they are the experts with all GM vehicles, they will be the best source for assistance. Should you need help connecting with one in your area, feel free to email us at [email protected] with your forum username in the subject line.