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

Had my 2017 TRD Sport V6 in a couple of weeks ago for the third brake light seal recall. The tech did a multi-point inspection and the Service Advisor called me to say they found an oil leak on the passenger side head. Apparently there is a check valve that is pressed into the head that is leaking. Of course, the check valve is not serviced separately and only comes as a head assembly. Motor needs to come out to replace, to the tune of $11k all in because of course I'm out of warranty. Obviously I declined.

The leak is very slow (barley dripping), and runs behind the power steering pump, dripping a little below it.

My truck had the timing cover leak and that was fixed under warranty about 15k miles ago. I inquired if they thought it was the same issue, and after checking he said it was not. Not sure I buy that, but I'm not recalling exactly where the timing cover leak was (aside from around the PS pump), and I can't find any schematics of the head to locate where this check valve is so I can investigate further. I have a cheap borescope that I can use to take a closer look as I narrow down where it is coming from.

The Service Writer claimed that the check valve leak is common for third gens but I'm not seeing a lot of info out there. Is this a common thing as the dealer suggests?

Even if it is the timing cover again, feels like after 15k miles the dealer would be reluctant to remedy the issue as workmanship so I may be stuck with it either way. It's a slow leak and the oil level never really drops beyond a 1/2 quart every 5-10k miles which feels like a normal thing with a truck with 86k miles. Still, I don't like knowing it's there. Open to ideas or suggestions.

 

Year? Engine?

 

Sorry - Though I had that in my visible profile. 2017 TRD Sport with the 3.5l. Updated the first post.

 

So I’ve been on this forum a few years now and I don’t recall seeing anything like this. I’m sure it has happened but haven’t seen it. This is pretty curious.

 

I call bullshit. Dealer made it up and gave you a outrageous estimate to make you go away when it is probably the cover leaking again and he doesn't want to answer for it. Not that he has to.

 

I say go to a private place or another dealer like you never went anywhere before.

 

Yeah, this definitely warrants a second independent evaluation before pulling the trigger on any repair.

 

That’s nuts! A new engine is only 13K.

Driver is Left, Passenger is Right.
Valve Cover (LEFT) - Toyota (11202-0P032) ~$250



Valve Cover (RIGHT) - Toyota (11201-0P010) ~$250




i don’t see what they are referring to in either of the pictures (either side).

 

An oil check valve in the head would most likely be there to prevent oil drain down. It would be inline with the Oil Passage and internal.
They diagnosis that they gave you sounds bogus.

 

Looking at an unassembled valve cover will probably not be useful for identifying a component that is part of the head.

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The FSM goes into teardown/rebuild of the heads as far as all of the typical stuff like valve, guides, seats, studs and also includes press fit pins and the spark plug tubes but it doesn't mention anything about a check valve or any valve that is pressed into the head.

 

I either read or misunderstood it to be something pressed into the cover. Agree, cover won’t reflect what is in the head. However, why would a head leak oil externally? Venting and flow is typically to cover.

 

A head could leak oil externally for any number of reasons. I guess it would have to be an air or oil hose/line to somewhere else if it's exiting the head outside of the valve cover, though. If it's really a pressed in part that is leaking, it's probably into an oil galley or a cavity that has contact with oil. I would guess that a check valve pressed into the head would be steel and the head being aluminum would require a very high interference fit to prevent thermal coefficient of expansion between aluminum and steel to result in a loose interface when at operating temps. The smaller the diameter of this press interface, the more interference it would need relative to the fit diameter. All of this is assuming such a valve exists.

 

I've had lots of heads off Toyotas new and old, I've never heard of this valve.

It's likely a timing cover.

Also we all have learned the engine does not need to come out. Rack and diff, yes. Engine, no.

 

Thanks for the replies. This seems to confirm my thoughts that it's the timing cover (again). It also seems to confirm that this is not, in fact, a 'common issue' as it was told to me. I don't see anything in that diagram in the FSM that shows the valve. He did say it's not serviceable and essentially a part of the head, so maybe it wouldn't be mentioned?

I definitely wasn't going to pay $11k for that - as mentioned, a brand new engine is not that much more. I'm willing to live with it if it never gets worse, but I'd love to have it fixed if it's reasonable (or covered by the original dealer for workmanship).

When I had my timing cover fixed under warranty they took the motor out. He explained it can be done either way but it's easier for the tech to drop the motor out the bottom as an assembly.

 

@uwjberg,
Hey I'm following up on your situation Sir!

Back in 2018, I purchased a New 2018 Tacoma (TRD Off Road), Financed through TFS, even bought the Extended Warranties.
I have kept up on Oil Changes, Routine Checks and Tire Rotations.
I passed 100K Miles around February this year and had a 100K Mile Service and Check Up by the Dealer. NO ISSUES found from Dealer.
I took it back in around Mid July for another Oil Change (this time coming up on 120K Miles). They said there was a minor oil leak but that the mechanics did not have time left on the clock to investigate and a separate appointment was needed to diagnose the leak.
I took it back in yesterday for diagnosis, and the Dealer/Mechanic gave me the following diagnosis (in-line with your issues above):
"Oil leaking from right side cylinder head has seepage from check ball. cylinder head assembly would have to be replaced." and they verbally told me I was in the $7K range for parts alone...

Just curious if you ended up replacing the heads or the engine entirely? If you did not, did the leak get worse this past year? Is it as simple as keeping an eye on the oil levels?
I'm just trying to weight the gravity of this leak. Upwards of $7K is astronomical for me and ultimate would put be back into financing for a vehicle I just spent 5yrs paying off.
Sorry I'm venting, but I assume you, of all people, can understand my frustration. Especially when the majority of consumers recognize Toyota as such a reliable manufacturer.

Any help/insight is greatly appreciated!
Best,

CJ

 

I have read A LOT of oil leak threads on the 3rd Gen, as I have one. I don't remember ever hearing about a confirmed check valve leak. If the oil is coming from what looks like behind the power steering pump, that has been a front timing cover leak every time. That is where the leak starts because of the intersection of the head and block. If you follow 'The Car Care Nut' on YT, he has a discussion about this and the 2GR-FE and FKS engines. He is a Toyota Master mechanic

 

I wonder if there telling you about an oil gallery plug...

 

I had the same issue. A buddy of mine works at a Toyota dealer as a service writer and he went to town with my third party warranty company to try and get them to pay for it(also estimated at $11k) but they fought pretty hard against it and declined so the shop foreman tried to jb weld it as best as they could and put it back together.

2016 and 2017 have this early version of the head which is shared with other models that use this port however on the tacoma its just plugged with a press fitting that with enough heat cycles will start to leak. Starting in 2018 they dont have that specific issue anymore. Thats what my buddy said anyway.

Unfortunately I can’t find or didn’t save the photos from the little scope camera so here’s photos of it sitting at Toyota while the great warranty debate was happening lol.

 

Thanks all.
The Service desk told me that one of Toyotas top mechanics looked at my truck and has seen this issue before. When he saw the leak, he immediately knew this cylinder head has seepage from the check ball.
They cannot provide pictures without a “tear-down”. I attached a picture looking from the right wheel, just past and behind the alternator you can see the oil coloring. Based on this view, the mechanical knew it was the check ball in the cylinder head. Yet this can be confirmed without a tear down. Catch 22.

 

Also here is the “report”.