Crude Oil Leak

Hey Yall! I got some black liquid drippin all over underneath my Taco that been bone dry for 115k miles. Now overnight it’s leakin like the titanic! I took a look from under the hood and underneath. Appears to be running down on drivers side below the valve covers but way up in there looking up from below. Hoping it’s not that dang rocket boosters…. But I ain’t plum sure. What ya thinkin?

 

The fact that you have crude oil in your motor could be the problem.

 

See figures 1, 4, 6, 7, and 8 in the attached file.
Other than that, you just have to "look harder".

 

Thanks for the PDF. I reckon I’m gonna have to dig deeper tomorrow. I sprayed everything down w degreaser for starters and power washed it off. There’s so much oil blown all over it’s hard to see anything, other than a trickle trail down the backside of the motor/transmission mounting. But it’s definitely coming from above that.

 

PCV valve could be plugged/stuck

 

following

 

Change your Pvc valve

 

If it happened overnight, almost certainly the PCV valve. Here's a really useful thread on it:

https://www.tacomaworld.com/threads/pcv-valve-check-it.826747/

The valve itself is less than $15, so if this is the case, could be so much worse. Best of luck!

 

I took my truck into the Toyota dealer. They claim it’s the main seal. They don’t recommend replacing the PCV valve even tho it’s got 115k miles They’ll be happy to replace the main seal…. For $2400. ☠️

 

Let er' leak! As long as you watch the oil level it will cause zero harm!

 

i don't think you should be running straight crude oil

 

Inspect/replace PCV valve, try swelling the seals with some good high mileage oil, then keep an eye on it.

If it stops leaking then excellent, cheap fix. If it continues leaking then you can go for the big repair.

Had a 4-banger 2004 camry that was leaking in multiple spots, I followed the procedure above and all leaks stopped. Your mileage may vary.

 

Oil that is, black gold, Texas tea.

 

Oh it’s not straight crude. 50/50 mix with Coppertone suntan oil since I live in FL.

 

There is your problem. If you live in FL, you have to mix a minimum of 7.5% of snake oil

 

FYI- I replaced the PCV valve. The oil leak is def 95% less for sure. We’ll see what happens after some heavier highway driving today.

 

That might have been it. Just keep an eye on it & the oil level.

Crude, that's just rude, lol. Good luck

 

I sprayed the entire area with foaming degreaser and scrubbed it clean. After 80 miles or so, there’s still a tiny bit of oil at the bottom of the motor/trans seal. I’ll keep an eye on it…. But it’s MUCH less than prior.

 

High mileage oil is your next step to see if you can get those seals to swell. I would run high mileage for a couple thousand miles then switch back to regular oil and keep an eye on things. All synthetic oil has seal swell in it but high mileage has more.

I run 5w30 in my 3.5L. Highly recommend it. The power of this truck is way too high in the rev band for 0w20. Pistons running at high RPM on the highway can get hot very fast. One of the things I look for in oil is a high flash point to prevent high temperature breakdown of the oil. The Mobil 1 5w30 I'm currently using reports a flash point of about 467 degrees Fahrenheit.

Every time I've come home from a long roadtrip and drained the 0w20 the next day its had the consistency of water. The oil had definitely broken down, way before its service interval. 5w30 has not done the same to me.

Try the thicker stuff, hopefully you find your issue completely resolved.

 

I would also love to replace your working rear main for no reason

see how it works is, I buy the seal for $5
play around with music, turn a wrench, maybe crack a beer
finish it
then you put $2395 in my hand and I go party
win win
one I did was put on with a Mountain Dew as that's all I found to fit for a tool. You can even drink it included in the package.

call when you're ready

OP, things can look like a rear main, and not be a rear main
which you need to make sure of.
Oil moves. Down due to gravity. Backwards due to forward movement of the car and fan blowing plus wind.
And it follows pathways based on the shape of the engine.

Things can look like a rear main and not be a rear main.
Case in point. I saw a guy who forgot to stick in a dipstick tube. Or something like that. Well, he thought the rear main went bad and pulled the trans...

No, it is not.
You run oil, and that's it. If you have a leak, you fix the leak. You do not have a leak and then go "well, I will not fix the leak, and to respond to the leak I will put molasses in my motor".