Just looking thru the maintenance schedule and notice that the valve adjustment maintenance calls for an "audible inspection" at 48 months. My Sienna is actually due now for the same thing. Just wondering if anyone has ever had this done to a vehicle and if it's something as simple as someone sticking their head under the hood with the engine running and listening how it sounds, or is their something a little more to it (some kind of equipment involved). Knowing dealers, I'm just concerned the "audible" inspection is just a ticket for them to tell you a full adjustment is required.

 

Sounds sort of like a valvetrain cardiologist.

Wonder if the techs had a special class on this (being facetious). I think its an easy-out remedy Toyota came up with because of all the blowback they're probably getting over the cost of getting adjustments done on older vehicles.

Our 03 6cyl 4Runner has 96k miles. The maint. schedule calls for checking valve clearances at some point (I don't remember offhand when, but I think its about right now). When I talked to the SM about it, he said it would take 23 hours to do, and it was complex. I've decided to completely skip this, unless something happens engine-wise, and then it could be too late.

Toyota: try hydraulic self-adjusters. Yes we'll all happily pay an extra $xx for the vehicle up front for the additional cost of the system.

I notice the 3.5 in the Avalon has hydraulic adjusters, and maybe in the other models that use this engine as well?? Hard to easily find this info.

 

Don't worry about it.

One does have to know what to listen for because the Fuel Injectors also make a "tic-tic" sound that can be confused with excessive valve lash.

On the last Toyota I owned (4AL engine), I did the valve adjustment at 100k/miles and they were still very close to spec. I was only in there because the valve stem seals dried out and I was burning a bit of oil.

 

Am I the only one, or does someone else think this sounds like B*S*. Twenty three hours (3 days in the shop) of labor to measure valve clearance?

I would definitely get a second opinion from another dealer or competent shop!

 

OMG!

I missed that part. 23 hours?!?! That's a top-to-bottom engine rebuild!

That's too-too funny.

Were it me... I'd be sure to get the estimate in writing... then the fun would really begin.

Bravo Sierra?? Ya think?

 

2-3 hours?

 

I would imagine checking valve clearance would consists of taking off cylinder head cover and timing chain cover to set TDC. If you can do it on the car then the whole think shouldn't take more than 1-2 hours for experienced mechanic. Now, if you need to take the whole engine out to get to timing chain cover, I can see how that could take much longer, but not 23 hours. I need to look into service manual to see what it says about this whole thing, but either way valves should be close to spec for at least 50k miles. If the whole valve checking consists of listening to valve's noise, it's pretty much BS just as much as many other visual inspections. Toyota has non hydraulic valves , Honda uses belts instead of timing chains in interference engines, which means you need to change the timing belt every 100k or risk major valve train rebuild, possibly whole engine trashed, if the belt was going to break.

 

My 92 Toyota pickup suggests periodic valve adjustments. I now have 397,000 miles and the valve cover has never been removed. If it is not noisy its ok.

 

"If it is not noisy its ok"

Maybe. Or too tight.

Honda used to spec. actual valve clearance check (not just listening for excessive clearance), for vehicles like our previous '91 Accord:

20,000km or 12mo, whichever comes first

Currently they say something like every 105.000km, or sooner if they sound noisy...

That's a gulf of difference, and I don't the cylinder head and valve design has changed that much.

In my experience, I found they tend to be off a moderate amount, usually too loose, at the first inspection, and then not much after that. Accordingly, my tact would be to do an inspection early on, say around 10000km, and then maybe after another 30000km. If they're still on spec. at that second check, then increase the interval a bit more.

 

Tight is what you need to worry about as the valves in time will bed down in the seats and this automatically tightens them. When I adjusted mine I found two on the tight side. This is not a hard job but very time consuming. Taking off the cover is the easy part, feeler gauge Int at .19-.29 MM. Exh at .38 -.48 MM. Then if they are off you need to pull both camshafts, and change the lifters which come in 35 differant sizes in increments of .200MM. now it takes a lot of dicing around with a micrometer to find the right size lifter to purchase and usually need to order. The lifter sizes are from 5.060 to 5.740 MM. Good luck and have a nice day. I will have to admit this thing is easier to work on then my Gulfstream V lol! I would rate this job at around 8 hours total time.