Valve Cover Leaking Oil?

Getting what appears to be some oil where the valve cover meets the head. There's a shiny part which is where I wiped off the grease/oil/dirt.

Looks like valve cover gasket leaking oil a bit slowly... Second opinions?

 

Welcome to the club.
Mine has had that same looking “leak” for years.
Never gotten any worse in 4 years since I noticed it.
I consider it more of a seep than a leak.

I have chosen to leave it be, until it actually leaks down the head and block and causes an issue.
Yes, this is lazy. But that’s the option I have chosen.

 

In my opinion, a little seepage is nothing to worry about. I changed them on my old T-100 but not until it left a drip on my driveway.

 

I just changed mine last weekend, after years of seepage it got worse. Got the OEM gasket for $15 on ebay and it was easy to change.

 

I know this sounds too simple but try tightening the valve cover bolts. I haven’t had the problem with my Taco but I’ve had other vehicles the leaked from the valve cover and tightening the bolts resolved the problem.

 

Guessing here, since the plugs go through the valve cover, wouldn’t there also be a gasket for each hole? I helped someone do a 740il, it was hell. It had, for each cover one outer gasket and 4 individual gaskets for each plug hole.

I do know the formed aluminum covers are superior to the old stamped steel ones.

 

More likely a timing cover leak that is sweating upwards.

I would wash it off and monitor it. That's not a concerning leak.

The 4.0 likes to leak right above the power steering pump on the timing cover and it disguises itself as other leaks.

 

this is called seepage
leaks can fall into different categories
their effect also can be different
if you leak oil onto a frame, no problem. Most people pay for that. It prevents rust.
If you leak hot engine oil onto a coolant o-ring below it, it will swell the seal and cause a coolant leak.
It is generally not good to get fluids into things, such as coolant into wires. It's called coolant migration.
Where it gets wicked up (water) through the wire, deeper into the harness causing damage.
the same way that if you dip the end of a wire into a jar of saltwater and let it sit (most of the wire outside, dry, on the table); the water will eventually climb through the wire and spill onto the table. Not good to have that happen in wires to an ECU/computer

another way to test is cleaning things. Not just (UV?) leak detection additive into oil that smells bad and can be seen with UV flashlight,
but also cleaning with a solvent like brake cleaner. Maybe a brush and degreaser
then you spray a leak detection spray. Such as $4 gold bond talcum foot powder from WalMart. It's white and leaves a film.
When oil gets to that film (leak) it changes color and gets wet.
That helps indicate where the leak is coming from, and how severe/fast it is.
Leaks only get worse with time. But you may still have some time.

bolts can loosen over time
the metal they bolt into can fatigue and give at the surface allowing the bolt to lose tightness as well

leaks do not go upwards
they go downwards due to gravity

timing cover reseal is probably harder to do than a valve cover reseal

 

Yes gravity! I’ve seen many times people see a wet oil pan and gasket automatically assume to do the oil pan gasket. If I see a tiny trace of oil coming from anything above the oil pan, I fix that first. I’ve seen a tiny leak from a valve cover bolt grommet drool all the way down the engine to look like a oil pan gasket leak.

 

The gaskets for the holes are all connected to each other as well as the outside so each valve cover is just one gasket.

 

considering my timing cover has been seeping oil for years and it still isnt at the rear of the valve cover. Im gonna say go ahead and replace that valve cover gasket. Degrease and spray off and monitor from there. if you have oil buildup near the square cover to the lower right of the PS pump its just the normal timing cover seep. In that case, let it be or pay thousands.

 

I took my truck in for a regular check up with a new mechanic today. He mentioned that he saw some seeping on the top of the PS Pump. Didn't really suggest replacing it b/c the part is so expensive. After reading the forums, I'm wondering if it's really a timing cover seep. Any chance you can send a picture of what yours looks like? Embarrassing to admit, but I don't know where the timing cover/PS Pump are. 2016 Tacoma. Thanks so much

 

You have a 3rd Gen Tacoma.
It wont be the same. Us 2nd Gen guys have the 4.0 engine.
You have the 3.5?

 

Yep, 3.5. Mechanic didn't seem all that concerned about it. Said it was "seeping a little." Unfortunately, if you google power steering pump seeping a little, about 1,000 threads about the timing cover leak on TW come up. I've never noticed anything leaking under my truck or had any problems. Would never have known anything if he hadn't mentioned it. And honestly I don't see anything that looks off under the hood...

 

I am not familiar with the 3rd Gen 3.5 engine.
I do know they too had a timing over leak issue.
And some were covered under warranty.
If you go over to the 3rd Gen section. I bet those guys can help you out.
https://www.tacomaworld.com/forums/3rd-gen-tacomas-2016.186/

 

I’m a forklift mechanic. Forklifts have hydraulic tanks that hold in the neighborhood of 15 gallons. Many times I’ve seen a leaky hose low enough to siphon the entire tank onto the floor overnight, I call it the lake.

Internal combustion lifts have a reversed radiator fan, blows from the engine, through the radiator, and out. So it’s really a big vacuum cleaner sucking up anything on the ground, up into the engine bay and into the radiator. So small seepage leaks are further masked by dirt hitting it then falling off.

 

Hey, mine does that too! Except a bit more than yours. Doesn’t lose enough oil between changes to bother me too much.

This is what I did when I first noticed it. 2 of the bolts were more or less finger tight and it doesn’t look like it’s leaked since.

 

You are in a different category. I am yet to do a 3rd gen reseal, but you are out of warranty i would assume. On the third gens there were some batches that got incorrect gaskets/rtv in the wrong spots on the head gasket. Techs will recommend the timing cover because they are thinking of the 4.0, on the 3.5 is usually the head. Watched a guy do a reseal on a 3.5 2017 timing cover only to have it come back a few months later. ive seen 2-3 tacos leaking oil at the corner of the head. its very unfortunate. My leak will look different from yours, if you post a picture of yours i could probably figure it out whether its the timing cover over head gasket.

This is a 4.0 timing cover leak. Thankfully i go through so much mud that my oil leaks stop themselves. My rear main seal recently became "wet" tried running some blue devil gasket resealer to hackjob rememedy it. Trying to keep this 4.0 alive till i can secure a low miles early 4.7 v8 to swap in

 

Not a leak. Try to snug the valve cover bolts a little. You may find a couple a bit loose.