Toyota 1AR/2AR (4 cyl) VVT startup rattle

I have a 2012 Highlander 4 cyl (1AR-FE 2.7L) with 130k miles. It's basically a perfect appliance except for one thing.. It has begun to make a hideous metal on metal rattle sound - but only momentarily - during cold starts until the engine builds oil pressure. Here's a good video (not mine) of the exact condition: https://youtu.be/FzzboZDObbs

The rattle is apparently common and is subject of Toyota T-SB-0041-13. The TSB outlines a procedure to replace the intake VVT gear, including all the misc stuff required to get in and out.

The internets and YouTubes say two things: 1) The rattle is common in Toyota VVT engines of a certain age... 2) I can probably drive it for another 100k miles and ignore it...

Since I intend to keep the vehicle for a long time, I'm inclined to fix it. Therefore, I am talking with GRM because the internet shows people being quoted 1.. 2.. even 3 thousand bucks to fix this. That seems crazy when the TSB indicates 2.6 hours of labor (and about $300 worth of parts).

Question: Since the diagnosis is done - how much should it cost if I choose not to DIY? When I see 2.6 hours in the TSB I think that should be the labor bill - am I misguided in that line of thinking? I would gladly pay Toyota (or an Indy mechanic) for 2.6 hours + parts knowing this is a repair they have done many times before.


...And lastly - I'm leaving this DIY link here for myself and others:

https://www.rav4world.com/threads/diy-t-sb-0041-13-cold-start-death-rattle-2ar-fe-vvt-i.300019/

Check the labor time.  2.6 may be the warranty rate, which is usually the normal rate divided by some fudge factor because they don't want to bleed money too much paying people to fix things for free.  (Ford is bad for this.  Jobs may have their labor time slashed to 25-30% if done under warranty)

Thousands sounds like they are quoting replacing the chain and guides, which IIRC is an engine out deal, if it is anything like the V6.  A good CYA measure to prevent a comeback.  But unlike, say, HONDA, Toyota uses a wide pitch chain thst doesn't wear out in 100k miles and get knocked a tooth or two off time when the phaser is finding its end stops on a cold start.

Thanks Pete. How can I "check" the labor time? All I have is the TSB

http://media.fixed-ops.com/Toy_ServiceBulletins/sb0041t13.pdf

In reply to OHSCrifle :

Other automakers list the warranty/out of warranty labor times in a service bulletin.

Presumably, if it is out of warranty, you are supposed to buy a new Toyota.

Also, the issue definitely did not stop in 2013.  Have seen newer 2ARs do it at about 70k.

I've never done the repair, but swapping cam sprockets while holding the chain up and hoping it never falls off time at the other end, gives me about as much confidence as sticking my hootus in an operating blender and hoping the blades are too far away to make minced Pete.  I'd want to take the cover off to do the repair, too.

In reply to Pete. (l33t FS) :

Okay thanks. Your description of the process has me leaning hard away from trying to dig in to this myself...

Curious to wait and see if others have intimate experience with the fix.  

Interesting final paragraph on this page:

https://www.motorreviewer.com/engine.php?engine_id=78

1AR-FE Engine Problems and Reliability

The engine turned very good. We didn't find any noticeable problems or defects. The engine is featured by a knocking sound from the VVTi system when it is cold, but this doesn't affect reliability and longevity. Cylinder block longevity limits the engine life, and it is about 150-200k miles.

Now that I am at work. 

Warranty time is 2.6 hours, out of warranty is 17.5. (Not a typo, they berk technicians for warranty work,although that is for both sprockets as I could not find a single labor time for actuator. )

Speaking with my service manager, who was a Toyota tech until recently, the biggest issues with going it cheater-style is first, compressing the tensioner, and two, getting the bolts out without dropping them into the oil pan.  9 out of 10 times, he says, you lose a bolt and have to fish it out with a magnet.

Holy E36 M3!!

...something still doesn't smell right.  Going to do a little more digging

In reply to Pete. (l33t FS) : truly appreciate the info 

VVT rattle by bad phasers, is this the equivalent to the 80 timing belts? 

My 2012 honda crv does the same rattle, and so do a lot of others crvs. Yep there is a TSB for this also. Mine has been doing it since about 60K,. I am starting to worry as I am at about 140K now and figured that was a lot of borrowed time. With the Honda I have read that there is an updated part, but a lot that have had the updated part installed at their expense and stated it came back with in a month.

In reply to lrrs :

Hondas definitely will jump time when let go long enough.  Although this is more due to the fine pitch chain wearing out faster, and also the fine pitch teeth on the sprockets having less tolerance for slop before they allow the chain to slip over the teeth.

Inside the cam phaser/actuator/VCT unit (depending on which manufacturer's language you are using) is just basically a gear shaped inner, an an internal gear shaped outer, and the solenoid allows pressurized oil in the cavities on one side or the other of the teeth/vanes to move the cam back and forth.  Overnight, the oil will bleed out.  There is a lock pin, whose sole purpose in life is to lock the unit in place full-retarded when there is no oil pressure and the chain is turning the outside of the sprocket.

So, the way it is supposed to work is, you crank the engine, the phaser, empty of oil, runs all the way to full retarded. Then the lock pin pops into place and holds the assembly locked until the engine has built enough oil pressure to unlock it.

What the rattle is, the lock pin fails to engage, and the two halves of the phaser are slamming against their stops until enough oil pressure/volume builds to refill the cavities.  This puts all sorts of stress on the chain and tensioner and everything else in the system.

..and the cold start noise is gonzo. Found a local independent Yota specialist and got the camshaft timing gear replaced for $925 - (Toyota) parts and labor. Had a second quote for $1,900 so I think I found my new mechanic for anything I can't do myself. 

Feels Weird to say it's a good day having spent that much money (plus four new tires last weekend) but it's been a fantastic car since I picked it up with 80k miles. And some preventative maintenance is A LOT cheaper than a new SUV.