I've done one these V6's so I know intake plenum removal is required. If it's taking you 3-4 hrs just to get the plenum off the intake manifold, you have got to be including your 90 minute lunch break! LOL
At any rate and as stated earlier, this is one of those jobs where the stereotypical "flate rate mechanic" would try to get away with only inspecting/servicing the forward bank. Knowing this, I would take measures to ensure that the job that I pay for is performed. Tattletale marks.
Thanks for the input, Ray (et al), but just a note...this is the second time you've mentioned a 97 Avalon. Mine's a 99 (post 8 in this thread). This would be another one of those distinctions without a difference ;-) if the 97 also uses a 1MZFE.
I just find it a bit surprising that
1) Toyota specifies a $450 expense as routine maintenance, and
2) both dealers I've spoken to act like it's wasted money and say in so many words that I'd be the first to do it.
How many owners actually DO this scheduled maintenance? Do they get better performance than those who don't? (And how would that be meaasured?) And if the performances (however measured) isn't significantly better, maybe Toyota could remove it from the recommended maintenance schedule and save us all some anxiety (and bucks).
4 hours is pretty quick for someone who is not twisting wrenches every day. Mitchell and Chilton pad real times by as much as 25% in case the tech runs into trouble or adjustment is needed and so they sell more time guides so the low end of my guess of 5-6 FRH is probably not that far off.
I don't know the reason for specifying something so expensive as routing maintenance, although it would be only once every 4 years if you drive
15,000 miles a year.
I have no idea how many owners actually have their valve lash adjustment checked. In my experience with Toyotas with shims and/or hydraulic valve lash adjusters, valve adjustment varies very little over 120k miles. Like Philip, I'm a big believer in following factory maintenance schedules but on my personal vehicles, I have not bothered with checking valve lash - yet.
Does Toyota still sell engines with solid lifters? Were these engines actually solid lifter engines, or was this just a check of non-running clearance for hydraulic lifters?
Four hours to just check the valves????? D^&* and I used to bitch about my Jensen-Healeys. I always had to adjust those valves (fine British engineering you know). Of course I also always had the previous clearance measurements and a list of installed shims on hand, plus the worlds largest collection of Jensen-Healey (actually Lotus) shims (sorted according to actual size, not the often incorrect size etched on the shim).
4 hours to check (not adjust) valves would make me long for the days of OHV engines with adjusters on the rocker arms. Although I don't think any of the other OHC engines I owned were particularly difficult. As I recall both my Pinto, Mazda 626 and Datsun 280Z used finger followers and were adjusted by changing the height of the pivot on the fulcrum end (it has been a while). My Audi used bucket tappets, but the shims were on the top of the tappets and easily replaced (with the correct tools), but in fact never needed to be replaced - at least while I owned the car.
Ahem ... it would be a more 'timely' question to ask: "Did Toyota ever make engines with hydraulic lash adjusters?"
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Ed, get up to speed. LOL Cam-over-valve with solid followers is der rigueur. The variations in lash adjustment are (1)shim over bucket (heavy but easy to service), (2)shim under bucket (lighter because shim is only slightly larger diameter than valve stem), (3)selective bucket with no shim (lightest). All three systems hold lash adjustment longer than finger/pivot/arm designs.
Some Starlets sold in the U.S. had hydraulic lifters. I don't remember who supplied them, but they were not a traditional Toyota supplier and they had a fairly high failure rate.
Really? You mean Toyota can't figure out how to do hydraulic lifters? Later model Audis (and VWs and BMWs) with bucket tappets have hydraulic lifters that don't require routine inspection. My Jensen-Healey was the shim under bucket type solid lifter type. Damn things refused to stay adjusted.
But honestly, do modern Toyota engines really not use hydraulic lifters of some sort? I was thinking that the valve lash measurement was made with the hydraulic lifters collapsed to make sure parts were not out of spec. I thought direct acting solid lifters when out with the 70's. Of course if they are as good as the ones on my old Audi, then I guess hydraulic lifters are no that important. But it sure seems if you have a hydraulic timing belt tensioners, you could figure out how to do hydraulic lifters.
Hydraulic lash adjusters are "patch" for soft metalurgy and marginal design. When you do things 'right', such adjusters are not needed. BTW, a hydraulic lifter is a specific kind of hydraulic lash adjuster. Regarding your Jensen, there is proof that soft metalurgy will compromise the better design.
Regarding your second paragraph ... you're simply unfamiliar with valve train development.
BTW, there are no hydraulic timing belt tensioners that use engine oil pressure to operate. LOL Nice try, sly guy.
Whatever - many performance car manufacturers use hydraulic lifters or hydraulic lash adjusters or whatever you want to call them on anything but all out race engines. I suppose an Avalon might have an all out race engine...lol...well I no, I don't supppose something that bland has an all out race engine.
See
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BMW AG 3.2L DOHC I-6 (M3) "....with chromed steel, nomaintenance, bucket-type, hydraulic lifters. Valve springs are carbon steel wound....." ".....Cam Followers
"Most engines utilize a hydraulic steel cam follower. These types of followers have been used to prolong service life and durability of the engine...."
Apparently you are the one that is unfamilar if you think VW, Audi, BMW and Mercedes don't use hydraulic lash adjusters.
See:
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Replacing the timing belt on Toyota 5VZ-FE, 3.4 liter V-6 engines is a very difficult task. The professional technician has no means to effectively compress the hydraulically activated belt tensioner without spending additional time removing engine components. These popular engines can be found in 1995 and later T-100, Tacoma and 4 Runner trucks
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`&part_type_id&&part_id74 For Vehicle:1990 - 1995 Toyota 4Runner V6 2WD SR5 (Engine: 3VZE) Catalog Number:A5030-51937/OES $57.13 $44.95 Hydraulic type
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1996 - 2002 Toyota 4Runner Timing Belt Tensioner Model: 4Runner V6 2WD Hydraulic tensioner, not a typical bearing.
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I know of 3 other blacktop's locally which also have had intake cam pulley issues, along with the hydraulic timing belt tensioner which is meant to be replaced at the 100,000km service.
"Whatever?" You're very question is about solid vs. hydaulic lash adjustment.
Let's define "race." Quite frankly, considering many four cylinder engines under 2,000cc operate in RPM ranges that a small block Chevy would consider to be borderline "race." For instance, the older Honda Integras had gearing that had the motor spinning merrily along at 4,000 rpm / 70 mph in 5th gear. Even my '03 Corolla with its undersquare 1800cc engine is running 2500 rpm @
65 mph.
snip
Those four manufacturers are not the sole manufacturers of automobile engines. And I hasten to add that GERMAN engineering is famous for choosing the more novel mechanisms to do the job ... just for bragging rights.
Your examples prove my point. "There are no hydraulic timing belt tensioners THAT USE ENGINE OIL PRESSURE" to tension the belt. Now ... there are self contained/pressurized chamber "hydraulically dampened" tensioners for cam belts. My Corolla has a similar gizmo for tensioning the serpentine accessory belt.
Well Ed, get back to me when you know sumthin' more! LOL
So you are saying that engines that use hydraulic lash adjusters are inferior designs? And finger type roller followers are inferior too?
So what, hydraulic valve adjusters can easily handle that range. Even a push rod Chevy V-8 with hydraulic valve lifters can rev to 7000 rpms. Do you honestly think that hydraulic lash adjusters can't handle the rpm range of the older Avalon engine? Don't you think it is a screw job for a "luxury" car to require expensive valve checking/adjustment when the technology to make this unnecessary has been widely available for 50 years? More third rate Toyota engineering. Load the engine up with gizmos and buzz words and then use 1910 technology in the valve train. How can you possibly defend crap like that? To see what hydraulic lifters can do, look at
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The power peak of over 500 horsepower is at 6300 rpm, and the engine's red line is over 7000. With all it's ancient solid lifter technology, the 2004 Avalon's "mighty" V-6 has a power peak at 5800 rpm and it has a 6000 rpm redline. Oh yeah baby, solid lifters really are important to that engine. Oh yeah, and Toyota has fessed up to publishing misleading horsepower figures, so that 210 hp they claimed in 2004 is more like 195 hp (see
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6965).
So you are claiming that a system that has no worth while performance advantage and adds hundreds to the maintenance cost is a good thing? No wonder you like Toyotas. Oh what a feeling...moving forward....whatever. It is ridiculous for a manufacturer to include all the gimmicky crap the Japanese love and then not include something as simple and well understood as hydraulic lash adjusters on a supposed luxury car. The German might not be the only manufacturer's of engines, but then outside of Russia (and apparently Japan), hydraulic lash adjusters are widespread. Even the French understand the advantages. The cheapest Renault sold in Australia doesn't require routine checking of the valve clearance (see
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). Do you really think that any engine that uses hydraulic lash adjusters is inferior (despite the lack of a performance advantage and the increased maintenance cost)?
You mean like the silly hydraulic timing belt tensioner we were discussing? Or Variable Valve timing that does nothing for the average driver except increase the complexity of the engine? Or fly by wire throttles that work like crap? At least BMWs drive like performance cars. As far as I can tell, the Japanese try to copy every named feature the Germans can think up. It just takes them an extra year or two to add it to the list of features. If the Germans though solid lifter were an advantage for a luxury car, they would damn well have them.
OK, but I never said it used engine oil pressure - did I? You added that little caveat. I just said it seemed that any company that would use a hydraulic belt tensioner should be able to figure out how to use hydraulic lifters. (Exact words were - "But it sure seems if you have a hydraulic timing belt tensioners, you could figure out how to do hydraulic lifters.")
Well Philip if you are going to try to claim that a third rate design is a good thing, I don't think there is any hope for you. Try this - Name me one contemporary mid-range luxury car from Europe or America that requires routine lash checking/adjustment (and I don't mean one of the ultra high performance luxury cars - an Avalon does not qualify for that class).. Then explain to me why it is reasonable for Toyota's flagship luxury car to do so. It's not defensible. And your claim that superior metallurgy makes non-hydraulic lifter acceptable is pure BS - if this was true Toyota would not specify that the valves needed to be checked.
And here is the really really funny thing - 2005 Avalons have hydraulic lash adjusters. I suppose even Toyota finally realized it was ridiculous for their flagship model to have solid lifters in a world where hydraulic lifters have been the used on high end luxury cars for 50 years. see
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: "Better Performance
"That's something that you don't always get. But consider. The Avalon is fitted with an all-new high-output 3.5-liter 24-valve V6. "All new" means this is the first application in any Toyota (the engine is a variant of the one developed for the current generation 4Runner, Tacoma and Tundra trucks-which have a North American orientation, as well). It has an aluminum block and aluminum heads; there are cast-in-place iron cylinder liners. Although it is 100 lb. lighter (yes, now we're talking mass reduction) than the previous Avalon engine, it produces 280 hp @ 6,200 rpm; 260 lb-ft of torque @ 4,700 rpm. (The '04: 210 hp @ 5,800 rpm; 220 lb-ft of torque @
4,400 rpm.) This is a vastly more sophisticated engine. All Toyota engines now have VVT-i, or variable valve timing with intelligence. The Avalon's engine is Toyota's first with dual VVT-i. Not only is the timing of intake cam varied, but the exhaust cam, as well. This permits the enhancement of duration, which is a contributor to horsepower.
........
"There is a new cylinder head design. Says Paul Williamsen, Curriculum Development manager, University of Toyota (Torrance, CA): "In some ways, it's kind of a throw back for us." What!! A throwback!?! Ah, but Williamsen continues, "It's the first engine we've had in America in about 20 years that does not have direct bucket-actuated valves. Instead, the valves are actuated by roller-follower rocker arms." Why the retro approach? "It allows us to have a hydraulic lash adjuster," he says. They've never had one on any vehicles in North America. It reduces maintenance. "More importantly, there's the roller bearing assembly, the roller-follower between the cam and the rocker arm. A conventional cam in a bucket lifter cylinder head is going to press down on a large flat lifter to operate the valve. That affects the grind of the cam-you have to have a very smooth shape. It's also interesting to think that this is one of the few areas of an engine that's designed to have direct metal-to-metal contact under substantial pressure. We've obviously not had any issues with that metal-to-metal contact, we can handle that through lubrication." The roller rocker allows them to have a more-aggressive cam grind, which allows the valves to open further, faster and holds them open longer."
So even Toyota is admitting you were full of BS in your defense of solid lifters. Notice that the roller followers with hydraulic lash adjustment is a very common arrangement in US OHC engines. Surprise surprise - they are actually better than direct acting tappets for performance and maintenance.
Well if Ray says it does, I'd tend to think it does, but I think maybe this once he is wrong. I looked at the Toyota Parts catalog for this item and it shows a non-hydraulic bucket style tappets (lifters). And the maintenance manual specifies checking/adjusting the valve clearances, which is usually a sign that the engine has solid lifters. However, it is possible that I am misunderstanding the Toyota documents.
I was really responding to Philip who was defending something that even Toyota is moving away from (solid lifters).
I still find it incredible that they aren't using hydraulic lifters on so many products. Apparently the new Avalon V-6 is the first modern Toyota OHC Vee type engine to use hydraulic lifters.
Nice discovery, Ed. Considering the length of time Toyota has seen fit ... and rightfully so, to avoid hydraulic lash adjusters, I would investigate the advantages of a roller follower over a flat surface follower with the hydraulic factor being a secondary consideration brought about by the roller itself.
I don't know which is sadder - Toyota's second rate high maintenace design, or your defense of Toyota. Apparently if something doesn't have a high buzz word factor, Toyota is willing to scerw the Customer by leaving it out (no other excuse for VTi without hydraulic lifters). And apparently no matter how bad Toyota screws it's Customers, you are willing to defend them.
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