Head Check Valve Oil Leak? Dealer Says it's not the Timing Cover

Here us the image from eBay. That thing on the left upper side could be the "check ball".
But, it is behind the cover. Even it has a seepage, the oil should not appear outside of the engine.
Check the timing chain tensioner cover, small square to the right of the ps pump

 

Is this 3.5 V6 engine?

 

11101-09552
HEAD SUB-ASSY, CYLINDER, RH
MSRP $1,099.45

https://autoparts.toyota.com/products/product/super-long-life-coolant-00272sllc2

yes 3.5 V6

 

Your description threw me off. Right wheel, alternator. V6 has an alternator on the driver's side(left wheel). I thought you have 4 banger.
"....attached a picture looking from the right wheel, just past and behind the alternator..."

 

Oh yeah definitely misidentified the object as an alternator then. As stated above I’m no mechanic.

 

This is such a stupid leak on Toyota’s part. All they needed to do is come up with a good gasket to to cover that small variance . Then use a form a gasket material on both sides and this problem for anyone could have been addressed. I wonder what they did different ( if anything on the new Tundra) although it does not happen on every 3.5 ,why would they leave it alone is extremely stupid in my opinion. What about the times it’s fixed on there dime. Very odd .

 

This engine never ceases to amaze me with it's spectacular designs.

 

Don’t pay that for a head. That’s ridiculous. You can get two reworked heads for about 900 bucks. With a 3 angle valve job. Upgraded springs and valves would be extra. That’s f’ing robbery.

And as an add on the price from Toyota for a cylinder head is a bare head. If you know how to do valves and springs it’s cheaper than anything you will pay someone else.

 

Np.
I would clean the oil off the side of the engine and monitor.
In meantime, ask them to point on the engine diagram where this "check ball" is

 

I know this thread is a bit old but it’s the only thing I can find on the Cylinder Check Ball Oil Leak. I have a 2017 Tacoma 150,000 miles dealership has resealed my Timing Cover 3 times. 2 under warranty and 1 time no charge after I called Toyota HQ. It’s now been leaking again for past 6 months, about a 1/4-1/2 quart every oil change. Today I pulled the Power Stearing pump to see if I could locate the spot and seal from outside. Was hard to tell exactly where it was coming from but I discovered the Ball Check Valve behind the pump. Couldn’t tell if that was the source of the leak but now I’m wondering if it was that all along. Cyclinders seem fine, when I had the timing cover sealed the 3rd time in Dec of 2023 the service manger mentioned something about checking the cyclinder but then told me it was indeed the timing cover again.
Anyway was wondering if anyone has got any more info on this Check Ball Valve thing?

 

Looks dry to me , doubt that’s where it’s leaking

 

FYI - This is an oil gallery plug. They are using a steel ball to plug a hole. It is not a check ball or check valve because the ball does not move. It’s just a plug.

That being said, I -suppose- it’s possible for it to develop a leak, but I think that would be extremely rare. In the photo, everything has an even coloring. I don’t see the ball as the ‘source’ of any leak.

As for the oil loss, most likely culprits are gasket leak or burning oil. Is there an area of the engine that is oily to the touch, or is dripping oil on the floor? Anyone else have opinions/experience about oil burn for an engine with 150k miles?

 

Having owned oily cars.. you’re right… leaks are typically gasket related. There are instances where it’s burning instead of leaking. Those would be via the valve stems or the oil control rings on the pistons. Those both show up as black/grey smoke. It’s typically obvious, but the best method for determining what is going on with your engine is to put your hand in front of the exhaust for 10 seconds and then look and smell. You’ll have oily and smell it. You’ll smell if it’s too rich or if you smell coolant. Good diagnostic tool. The fix for valve or rings is replacement/machinework. First thing you can do is to get the standard torque for valve covers, oil pan, etc and go around checking, tightening anything lose. I’m always surprised how these loosen over time. Second is remove your lower pans/skids and place a cardboard sheet under the vehicle when you park. Watch to see where it comes from (if it doesn’t, it’s burning it). If you find the area, but can’t locate… do some cleaning so it becomes more obvious. You can also use baking spray (it’s light oil with plenty of flour). The engine oil will show up dark against white.

 

Thanks, I will def check out the exhaust steam. Leak just recently has reached skid plate. I honestly am not cornered with slight oil burning and/or consumption between oil changes, just trying to mitigate any type of catastrophic engine failure and only trying squeeze snd other 100k out of this Tacoma. I’ve run nothing but synthetic oil and ethanol free gas in it. I’m just really disgusted by Toyota Motor Co for putting such a flawed engine in such an iconic brand. I paid a premium for a mid size truck, I expect a return on my investment. They’ve done zero to address these known issues and it’s obvious by the variety of diagnosis’s from their “dealerships” posted on forums like these about 3rd Gen’s. It’s a poor engine design. They are well aware but are playing dumb. Shame on Toyota, I will likley never buy another.

 

Excellent tip on the baking spray. I was thinking of something like the powder they use for doing magnaflux inspections. I found a few videos where they use foot powder spray. Maybe better than food-based spray - less attractive to rodents.

 

Eh, washes off very easily. But good thoughts…

 

Any updates on this? Having the same issue on my 16 Tacoma at 175k (leak is minor but looks at least a year/20k old maybe). From initial inspection and reading other somewhat confirmed diagnosis here, it’s the oil gallery pressed ball bearing that’s leaking near the power steering pump, not the timing cover. This video is my current suspicion but curious what you all have found before I tear into it or need to order parts ahead of time. Thanks! https://youtube.com/shorts/HBysj_Fiy6A?si=Szz9l4rqu8JvCI4c

 

My leak turned out to be the timing cover again, not the galley plug. Here’s how I fixed it. Took me an hour and $10 vs 20 hours and $5,000 at the dealership. I’m not a mechanic, just a fella fed up with this leak. It’s ugly but 10k miles later and still dry! Not sure why the galley plug couldn’t be sealed from the outside also?

 

I'm going to do this same thing soon, although I purchased

$12 Permatex 27037 Optimum Black Gasket Maker, 3 oz

Permatex 27037 Optimum black gasket maker, mainly because it is advertised as oil resistant.

Not sure if it matters, but I'm hoping it will work as well as the orange stuff you used!

 

I used permatex high temp, but what you have there will work. You don’t even need to pull the lines off the power steering pump unless you want to change the fluid. Just remove the 2 mounting bolts and swing the pump toward the front of engine. After I cleaned it up, I couldn’t really tell where it was leaking from, assuming somewhere near the galley plug where the cover and top of block meet. I probably used way more permatex then needed. Funny story, just took my mom to the dealership to buy a Rav 4, salesman says how do you like your Tacoma, he has a 2021. I showed him my fix and told him they tried to seal 3 times and failed(different dealership) he said he’s never heard of the issue…yea ok!