06 Tahoe Terrible Oil Leak

[Owen]

My 06 Tahoe has been leaking oil for years but over the past 2 weeks it has gotten substantially worse. Before, I could go weeks or months without having to add oil, but now it is terrible. It’s leaking onto the exhaust somewhere and I can smell the oil burning.

It covered the safety chains on my trailer with oil after towing 2 hours.

I added 2 quarts and had to add more the next day.

Any ideas as to what could make it leak this bad? Under the car there is oil everywhere so it’s hard to see where exactly it’s coming from.

Thank you

 

[Big Mama]

Welcome to the forum from Virginia. Sounds like it’s coming from your valve cover gaskets but I’d take a look at your oil filter and pan gasket too. You didn’t mention any smoke from the exhaust so it’s not burning oil. The size of this leak makes it an urgent repair before you lose too much and your engine quits.

 

[Owen]

I should’ve mentioned this, but I replaced the oil pan gasket a little over a year ago, and one of the valve covers probably 3 years ago.

 

[Big Mama]

the rear main seal is another possibility. Hop under it and report back on your findings.

 

[Owen]

There’s oil literally everywhere it’s hard to tell from under.

2 notable things:

Cylinder 7 spark plug wire has oil all around it, but this is on the side where I replaced the valve cover years ago. See pic

My oil pressure sensor does not work, and there is a good deal of oil around it.

Is it possible the leak is coming from the sensor? Thank you

 

[Tahoe14]

Clean underneath with brake clean, take it for a drive and look again.

 

[Sam Harris]

There’s oil literally everywhere it’s hard to tell from under.

2 notable things:

Cylinder 7 spark plug wire has oil all around it, but this is on the side where I replaced the valve cover years ago. See pic

My oil pressure sensor does not work, and there is a good deal of oil around it.

Is it possible the leak is coming from the sensor? Thank you

Yes, I had an aftermarket oil pressure sensor give up after about 200 miles and it was a catastrophic leak, as in low oil pressure came up on DIC. I’d take it to a car wash, clean all the oil you can off, and see where it’s coming from. Oil pressure sensor sounds probable, and that would be a hellova lot cheaper & easier than a rear main, so fingers crossed for you. Also, always get AC Delco sensors, but keep in mind, even they are hit or miss. I went through 4 total before having one last. That one was replaced again a few months ago, but it lasted probably 3 years. I keep at least one spare on hand now, and I’d recommend doing the same. Unfortunately, some of the OEM pars are still trash, but in this case, the parts store brands seem to be worse, though I have heard of a few folks who’ve been lucky with one working for some length of time.

 

[Owen]

Thank you for the replies. I forgot to update but I replaced the oil pressure sensor, and threw in a bottle of “blue devil rear main stop-leak” and my oil leak has basically gone away. It’s been over 2 weeks and I haven’t had to add any oil, probably driven close to 1000 miles.

The sensor was very easy to replace. Some people online were saying you needed to take the intake off but it’s easily accessible with a deep socket 27mm, a swivel, and extension. Hope this helps somebody.

 

[rockola1971]

Very common for the oil pressure sensor to develop leaks at the joints of its body. More common on aftermarket parts or very old OEM ones. That sensor is on your main oil galley!