How bad is this oil leak?

[Michigan]

I just got this truck less than a week ago and noticed an oil leak after sitting overnight.

I guess you would consider it a "minor" oil leak. I don't like leaks at all, I guess who would. Lol

It is definitely a bummer since I asked the seller if it had any leaks and he claimed no, that it sits in his garage and never leaks. When I looked underneath before buying it, I checked by the oil plug and I think that's the rear main seal location and it was dry so maybe he possibly wiped it down because now it shows a little witness. I will have to take pics. So I don't know if it's rear main seal or oil pan or other?

I had the same Tahoe last year that had a minor rear main seal leak and took it to a couple shops at the time and was told it was nothing to really worry about. I still don't like the fact of knowing my truck is leaking and on the driveway.

These pictures are over a 24 hour sitting. It's definitely dripping but not a puddle for sure. By looking at pics, do you think it's enough to effect the oil levels over time? Will I need to be refilling from the leak.

What problems can an oil leak cause and should I do anything about it or is it very minor and ok?

Also it looks like there is spots in different locations on the ground if you look at the last pic. Disregard the spot at the top because that was already there. Maybe I will have to lay down some cardboard and let sit overnight and report back

 

[Rocket Man]

The amount for 24 hours isn't enough to worry about other than it leaves a mess. You should keep an eye on your oil level anyway and will probably add a bit between changes. Oil leaks can be a challenge to locate. Good luck, hope it's not the rear main because in order to fix it you have to pull the trans which you probably know. The oil pan on a 2wd is pretty easy.

 

[PG01]

Bad, junk it... but light it on fire first...

 

[HiHoeSilver]

Don't get ahead of yourself. Put some cardboard down and be methodical for a few days and try to find it.

 

[PG01]

Don't get ahead of yourself. Put some cardboard down and be methodical for a few days and try to find it.

I still say burn it

 

[M1Gunner]

I'd start with the PCV system. Check to make sure it has proper flow. Restricted or kinked pcv hose or engine vent hose, damaged, incorrect or incorrectly installed pcv hose. All the above will cause excessive crankcase pressure, resulting in an external oil leak.
You'd be surprised that IF a restricted PCV system is repaired, seals will actually still begin to do their job again.


But I also like @Galante 's response, just burn that mother down!

 

[Michigan]

Bad, junk it... but light it on fire first...

I would but she's too pretty to do that. Lol

 

[corvette744]

Put some oil dye in it drive it for a week and black light it then you will know for sure were its coming from.

 

[Chubbs]

I hate to say it but that leak will definitely cause a drop in the overall oil level.

I've seen plenty of leaks that weren't even bad enough to hit the ground and required the addition of couple+ ounces bi-weekly.

The oil leaks even more as you are driving the vehicle, it is @ operating temp. and the viscosity decreases; you have no idea to the loss at this time since it just blows off. Until you locate the source and repair its worth checking the dipstick twice a week to get an idea of how much and how fast the level drops but it's a new acquisition so we know you will be thorough in its upkeep.

 

[Cajunrob]

Have a 96 Tahoe with 269,000 miles and a 2001 with 120,000 miles . The 01 leaks oil from the rear main seal. I just keep adding oil.

 

[Michigan]

Would a bad oil pressure sending unit cause a leak? My gauge goes to 80 psi.

For some reason none of my gauges move when the car is turned off because I was trying to test and see if it pegs to 80 with the car off also as I seen someone go in a YouTube video but mine does not. Also seen in a video that someone had a bad sending unit and it caused a minor leak. Not sure how possible that is for me but I think I'm hoping so instead if it being a rear main seal.

Is there anything bad about driving the truck this way until I get it fixed or do I avoid driving?

 

[Rocket Man]

Would a bad oil pressure sending unit cause a leak? My gauge goes to 80 psi.

For some reason none of my gauges move when the car is turned off because I was trying to test and see if it pegs to 80 with the car off also as I seen someone go in a YouTube video but mine does not. Also seen in a video that someone had a bad sending unit and it caused a minor leak. Not sure how possible that is for me but I think I'm hoping so instead if it being a rear main seal.

Is there anything bad about driving the truck this way until I get it fixed or do I avoid driving?

Driving it what way? The oil leak isn't a problem obviously, just keep an eye on the oil level. And just because the gauge says 80 psi doesn't mean it's true- it sounds like your cluster has a problem- the stepper motors are a known common failure. And even if you do have 80 psi (which I seriously doubt) it's not a problem unless it's pushing oil out everywhere which it obviously isn't otherwise you would have leaks everywhere including the pcv. You just need to figure out what your oil pressure is, and why your gauge says 80. Your leak could be coming from anywhere, the rear main is just one possibility.

 

[M1Gunner]

But yes that oil could be coming down from your oil pressure sending unit absolutely. As far as your gauge reading, the sensor itself may be shorted or you may have a harness issue OR as @Rocket Man mentioned your gauge motor may be shot.

Key on, engine off... what does the oil pressure gauge read?

 

[Michigan]

But yes that oil could be coming down from your oil pressure sending unit absolutely. As far as your gauge reading, the sensor itself may be shorted or you may have a harness issue OR as @Rocket Man mentioned your gauge motor may be shot.

Key on, engine off... what does the oil pressure gauge read?

Problem is with the engine off and turning the key does not activate any of the gauges. None of them move for some reason. Before turning engine on the gauge is at 0 like normal and when I turn the engine on the guage goes straight to 80 and stays there.

As far as the oil pressure sending unit goes. I called a few shops and got different answers from all of them. One of them said that just because it reads 80 doesn't mean it's the sending unit and it may be that the fuel pump is on its way out but the truck runs fine I would say he also said that if it was the sensor it would stay on zero and not move at all. Another said it could be the cluster itself or short.

The other shop said he doesn't think it's the sending unit and that I have great oil pressure if I'm reading 80.

I already have the part and am looking at around 150.00 for labor as I can't do myself.

I hope it fixes the leak if I get it changed

 

[06Escalade]

The PO lied about leaks. Obviously. I see bare metal, the black paint has washed away. A sign that this leak is chronic, and has been going on for quite a while. Years. A leak the PO did not want to spend the $$$ to fix. Nobody tells the truth, they never say why its really for sale. Well, whats done is done. You need to go to a car wash that has spray booths and hit that area with degreaser, then a rinse. Then watch. You gotta get underneath part way to be close, flash on and get some detailed pix. Let us know. Gear oil or PS fluid can also eat the wax and paint clean. I had a similar leak, similar bare metal. It was the PS gear seal. And.. gulp.. the front diff pinion seal.

 

[Michigan]

But yes that oil could be coming down from your oil pressure sending unit absolutely. As far as your gauge reading, the sensor itself may be shorted or you may have a harness issue OR as @Rocket Man mentioned your gauge motor may be shot.

Key on, engine off... what does the oil pressure gauge read?

Ok so maybe it was my own dumb fault unless I was tripping out when I tested this prior but with key on and engine off the oil pressure gauge reads 80psi with truck not running. It at 0psi to start as normal then goes to 80. So does this mean it's an oil sending unit not reading and the stepper motor in the cluster is fine? Or could it still be stepper motor?

 

[HiHoeSilver]

Usually pegged at 80 with KOnEOff is a bad sender.

 

[M1Gunner]

@Michigan Bingo, brother! Key on engine off and oil pressure is still pegged means that there is an open in the circuit, 9/10 its internally in the sending unit.

When you go to replace it you can verify by checking the resistance of the sensor with a multimeter. It'll read OL if it's gave up the good fight.

 

[corvette744]

 

[Michigan]

Hey appreciate you all,

Had the oil pressure sending unit replaced today and problem fixed as far as the gauge reading now. The old unit was also leaking oil but the bad news is I still had oil leaking in the driveway from a few hours of sitting. I hope this is just runoff oil as the guy said it was a mess and recommended to have it all cleaned up and check for leaks so I won't know for certain just yet if I have a leak or not

The shop guy said he will not be doing another one of those. Guess it was a pain