After taking my 2001 Toyota Tacoma into my Toyota dealer for a routine oil change they informed me that I had a leaky valve cover gasket and that it needed to be replaced. The repair would have been expensive, and since it was just a leak I decided to not make the repair. I have been driving with the “leak” since May of 2013 and have put about 29,000 miles on the truck. I have never had to add oil. There is no oil spot on the concrete where I park the car and I do not smell burning oil when the truck is running. If this thing is leaking, what the heck is leaking out of it? And if I haven’t had to add oil or any other fluids do I even need to replace it? Any input would be appreciated.
sounds like you answered your own question
Yep, ‘leaks’ are sometimes small enough to not worry about, like this one. As long as you’re checking your oil and finding no loss, I wouldn’t worry about it. I replaced mine because they leaked onto the exhaust manifold.
I call this “seepage” and you can safely ignore it. Pretend it doesn’t exist. It is totally completely harmless and meaningless unless it gets so bad that oil begins to run down onto your exhaust system and burn. If yours were that bad, you’d be using oil and you’d know it by the smell. It may never get that bad. Most don’t.
Over time, gaskets can take a “set”, lose their ability to push back at the metal that’s compressing them. Compare a used gasket to a new one and you’ll find that the used one is much thinner. That is the “set”.
The space under your valvecover is connected to the airspace in the crankcase via the oil return passages, and pressurized along with the crankcase by “blowby” in the engine. “Blowby” is the small amount of combustion that gets pushed past the rings. All engines have a minute amount, aging engines a bit more. Tired old engines can have enough to cause problems, but you aren’t there yet.
The oil that lubricates the camshafts and their corresponding parts simply flows back to the crankcase after being forced out the spots they lubricate by running down the cavities in the head’s top surface. Some of it can run up against the inner side of the gasket. The pressures under the valvecover can force some past a gasket that’s taken a “set”. That is what you’re experiencing.
Kudos for monitoring your car’s oil. Happy motoring.
Stop leak.
I strongly urge against adding Stop Leak for a meaningless seeping gasket. Your oil needs to travel through numerous small orifices to do things like pressurize the hydraulic lifters, and you do not want to interfere with its travel through these orifices with an additive.
Valve covers are an easy fix you can do yourself. Get good Felpro gaskets. Then all you need is the bolt tightening sequence. You can borrow a torque wrench, but I snug them with a 1/4 inch socket. Don’t over tighten, just snug the up evenly.
In defense of the dealer, the mechanic sees a leak he should point it out no matter how trivial it appears to be. The mechanic has no way of knowing what the oil consumption pattern may be.
The alternative would be to remain silent and then possibly catch the blame when a leak is discovered or causes a problem later on.
Sometimes referred to as dxxxxx if you do, dxxxxx if you don’t… 
Fandango I just had the oil pan gasket replaced on my 2010 KIA Forte 2.4L 30,000 miles. I had a non dealership oil and filter change performed in April and was informed of the oil pan gasket “leak”. Since it had never used any oil between 5,000 mile changes and had never left a drop on the floor I was not concerned. I check oil level weekly. About 2 weeks ago I was at the dealership having something else checked and they wrote up the gasket leak. 3 days later it was replaced under warranty. They showed me the old gasket and about a 1 inch section was discolored. That was the “leak”! I would not worry about your “leak”. Just continue checking oil level.
You might just try torquing the valve cover bolts.
With such a minor leak, I’d have to agree with @the same mountainbike, and not add any type of stop leak. And I wouldn’t worry about replacing the gaskets. Save the money and just keep monitoring your oil consumption.
Yosemite
Many thanks to all of you for the great input. The same mountain bike provided a great explanation of the mechanics of the thing. You guys have saved me a bundle!
Leaking valve covers are a common problem. I had to replace the gasket on my Corolla. For that, it was like a 15 minute job. It must be more complicated on the Tacoma for it to be expensive. Doing nothing is probably the best bet. There is some small chance the oil will get on the timing belt, which can cause problems, like the timing belt jumping a cog. Or slipping off. Next time in the shop ask your tech to check for that. If you decide to try tightening the valve cover fasteners per the post above, be aware these are not supposed to be very tight. If you over-tighten them, that will cause a heck of a lot more trouble than you have now as you will warp the cover. Ask the tech to check the fasteners and if loose, tighten with a torque wrench to Toyota’s spec.
On the v6 you have to remove the upper intake to do the left valve cover. It’s not too hard of a job. The gaskets get hard over time.
Stop-leak products do nothing for gasket leaks.
But they can work on seal leaks.
Tester