By on March 1, 2016

1998 Toyota Sienna XLE Front 3/4, Image: Toyota

TTAC Commentator MatadorX writes:


I am hoping you and your readership can give me some guidance as to how far to take a vehicle overhaul: mild insanity or full on broke?

The vehicle in question is a 1998 Toyota Sienna XLE.

It has been in the family since grandpa (who else) bought it brand new, finally abandoning Chrysler vans after three successive transmission failures. I inherited it very well used at 140,000 miles as my first car at 17. Since then it has taken me on countless road trips, junkyard parts runs to feed my fleet of 1970s AMC products, camping adventures, and daily commuting duties. It currently sits at 221,000 miles, which is at or slightly below average for one of these vans.

At long last, the Sienna’s reverse clutch gave up the ghost — and I’m tired of Fred-flintstoning it whenever I needed to backup. I pulled her into the garage, picked up the largest jackstands Harbor Freight sells, and dropped the subframe.

The question: Should I look into rebuilding the engine at the same time as the transmission is out? I got very lucky and scored a fresh rebuild from a wrecked Sienna for $150.00.

Before writing this van off as not being worth the effort at 220,000+ miles, I should note that every single system on the car otherwise is freshly replaced within the last 20,000 miles. Shocks, struts, strut mounts, control arms, rear control bushes, ball joints, sway bar bushings and links, axles, entire brake system (Power Slot Cryo-treated rotors/Axxis Ultimate pads), steering pump/rack/lines … the list goes on. The transmission will also be new, leaving just the venerable 1MZ-FE’s internals untouched on the van.

The only mark against the engine really is that it does use some oil, approximately 1.5 quarts every 3,000 miles. However, with the engine out on the garage floor staring me in the face, and otherwise inaccessible short of a 7+ hour job of dropping the subframe, it seems I am doing the car an injustice to just stick it back in there. Then again, this engine is squeaky clean, no sludge build up due to religious 3,000 mile oil changes.

Numbers wise, you can buy a “rebuilt” 1MZ-FE for around $1,500. However, these use pretty terrible parts and questionable machining, likely worse than a Toyota-built engine with 200,000. A better option, I located a new in the crate Toyota short-block for $1,500 (half price), figure another $1,000 into getting the heads done, a set of OEM Toyota HG’s, new head bolts, oil pump, and other assorted gaskets, and I’d have essentially a brand new engine for $2,500.

But, for a multitude of reasons, this is the best Sienna to have, so I am going to stick with it as long as possible.

Sajeev answers:

Quick question: Why not get a low mileage engine and transmission from an online junkyard? I think it will be both a better value, not to mention some rebuilders are rather shady.

MatadorX replies:

I would agree with you, the issue is here in California, concierge junkyard parts come at a desirability and thus huge price premium to elsewhere in the nation. Take a look on and the first page of most expensive listings will be mostly from California yards. If I had to ship it in from another state the price would be much higher. The transmission itself is already acquired, as a known good unit from a same year van in a wreck.

The only place likely to find a good, well cared for 1MZ would be a 1997-2001 Lexus ES300, due to more careful Lexus owners. That said, I would still need to source a Lexus ES300 with well under 100,000 miles in SoCal, where 200,000 miles is nothing for most Toyota products of this vintage.

Sajeev concludes:

Dude, I totally bow down to your knowledge. That van is soooooo lucky to have you as an owner. Definitely get a rebuilt motor, slam it in there and enjoy the van! This will be your cheapest and easiest route to automotive happiness in the long term.

Best and Brightest?

[Image: Toyota]

Send your queries to [email protected]. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

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40 Comments on “Piston Slap: To Love A Sienna Like No Other?...”

  • avatar

    We bought one of these for my Mother. It sits at 240,000 and only an epic hail storm has slowed it. I’m not sure had it required an engine swap if I could be sanguine about retaining the beast. I realize you have answered your own question by doing all the other work, so carry on. But, didn’t it even cross your mind to replace it for, say, $3000 and start over at a measly 150k?

  • avatar

    Put the engine back in, assuming it is not making any ominous noises and the compression is decent. If it ain’t broke don’t fix it. 2,000 miles/qt is not that bad. My limit is >1 qt per tank of fuel or spark plug fouling. You probably have several tens of thousand miles left in it.

    • 0 avatar
      87 Morgan

      If it still works just fine, why bother. 1.5 qts per 3k is Vtech Honda motor territory with 5k miles.

      This motor should be good to 350k or better based on what I assume to be your maintenance habits. I.E I am fairly certain you are the guy most of would want to buy our used van from should it be for sale and we needed one..

    • 0 avatar

      Yep, keep the oil topped off and t-belt changed and that motor has another 200k in it, seriously.

      Good on you for keeping the vehicle maintained and not just saying “it’s a Toyota, it never needs work” while worn suspension bounces and clangs around.

  • avatar

    I tend to agree w the others keep what you have and put the engine back in and live w the oil consumption, it is a well cared for van and congrats on that, I am sure you will be able to hand it down to someone you choose when the time is right.

  • avatar

    I have to go with the majority–if the only problem with your existing engine is a bit of oil use, stick with what you have. As long as the compression is good, just replace the wear and tear parts like gaskets, waterpump, etc. that may be hard to service with the engine in the car.

  • avatar

    Not recommending LSx FTW? I am very dissapoint.

  • avatar

    A little late now but if I was considering reinstalling the engine I would have wanted to verify oil pressure with a manual gauge before pulling it. That along with a compression test, if both were within factory spec I would put it back in and run it. You will likely get another 100k out of it and who knows what kind of condition the van will be in by then. If there are any oil leaks now would be a good time to address them while the engine is out.

    The only other option I would consider is a full rebuild of what you have. I personally would not stick a lower mileage junk yard engine in any vehicle I own. You have no service history and it could be in worse condition than what you have with half the mileage. It’s a crap shoot at best, and I don’t like to gamble.

  • avatar
    SCE to AUX

    I’d do a full rebuild, including the hard-to-reach sensors and fuel injectors. Then you know what you have, and you’ll avert failure of something you haven’t considered until now.

  • avatar

    A healthy 1MZ-FE’s oil consumption will not be detectable – this engine is worn out. It isn’t a low ring tension, 0W20 using Honda engine. This is an early 1MZ-FE, many of which had oil sludging problems. I suspect that’s what has happened. Rebuild or replace, since you already have it out.

    • 0 avatar
      heavy handle

      I agree. Do the short block, provided the head is good.

      Toyota camshafts can wear-out. The wear is obvious when you lift a valve cover.

      I know a few people who’ve run these vans to extremely high mileages. The only real trick is regular maintenance and rust-proofing (in the rust belt).

      It was a great van, but I personally wouldn’t have one. Those coat hanger-thin A pillars scare the hell out of me. Not a car I would want to trust my loved ones to, given a choice.

  • avatar

    You’re crazy. Not that there’s anything wrong with that. If I were you, I’d put the engine back in. In fact, I probably would have taken this thing to the junkyard when it stopped reversing.

    But you are you and the impression I get from your question is that you won’t be happy unless you go the extra mile, or extra $2500 as the case may be. I don’t think you’ll be happy with a crappy rebuild, either, the new short block is the way to go.

    The existing engine would probably be OK for the life of the car as the rest of us understand “the life of the car” but in this case, it looks like you expect it to be eternal. You realize, I’m sure, that you’re doing practically nothing for the value of the car but not every decision in life is measured in dollars and cents.

    Sometimes, you must just feed your inner craziness.

    You haven’t mentioned the wishes of a spouse, that could change things. I’m presuming you’re single. And I’m presuming you can afford this.

  • avatar

    I just want to salute Timothy for taking such great care of this Sienna.

  • avatar

    Keeping the engine is obvious to me, and the good news is you never have to change the oil/filter again. With so much new oil going in, it’d be silly to do so.

    Changing the trans fluid, once in a great while is a better idea. I’ll bet when it lost reverse, it still had the all the factory installed fluid in it.

  • avatar

    Directional alloys, sensible shapes, two-tone.

    They don’t make em like that anymore. Though the newer Sienna in higher trims is very luxurious and Lexus-adjacent.

    I’m with the leave your current engine in there crowd. It’s not broken, and there’s too much outlay for a different rebuilt.

  • avatar

    Nice piece. Personally I would look hard for the 1MZ 3.0 in a Lexus before going with a rebuild, but of course this gentleman’s schedule may not allow for much of a delay.

  • avatar

    “Since then it has taken me on countless road trips, junkyard parts runs to feed my fleet of 1970s AMC products…”. Holy Toledo! Good for you re: the AMCs, which may explain a few things. I would leave the engine alone but would replace hard-to-reach components while it is out, as several others have suggested. In the meantime, my ’87 AMC Eagle and I salute you.

  • avatar

    Hey guys, Tim here, This is my van/story!

    One thing to keep in mind as to why I made the decision I did, is that we have one very important factor in California many don’t take into account: Smog tests. Recently they made it easier to pass the test for 2000+ vehicles (My dad has a 1MZ ’00 Camry and it sailed through, no Dyno), slightly easier for 76-95 vehicles (unless you fail the visual), and MUCH harder to pass for 96-99 early OBD II vehicles. If I wanted to keep the van into the future, its oil use would fail it within one or two more test cycles.

    Basically after much mucking about as to whether or not to rebuild the engine, I decided to go for it, full bore. I am making a decent income right now with the luxury of living rent free for the next few months, and after seeing the car payments many of my buddies (simultaneously straddling college loan payments) are taking on figured it a no brainier since the rest of the van is pretty solid. A few thousand spent now to keep driving something paid off with $90/year reg and sub $500/yr insurance costs makes a ton of sense right now in my life at 23. A flashy guy I am not.

    I started out with a brand new in the Toyota Genuine Parts crate 1MZ short-block, scored for $800 on closeout ($3700 retail). I took the cylinder heads and 4 cams to a machine shop I have a good relationship with and had them do “the works” They ended up giving me my heads back cleaned, with 3 angle valve job, stem seals, cams tanked, valve shims adjusted, and resurfaced for $460 cash deal.

    I pretty much did a stock build other than that, primarily Japan sourced Victor-Reinz gaskets, upgrading to MLS over chronically weeping OEM composite HGs. Unfortunately quite a few Taiwanese/Chinese impostor seals tried to sneak into my master Reinz kit so those were sourced from Nippon, THO, NOK, Sankei, etc-basically Toyota suppliers. New head bolts were used, and since a complete Aisin/Mitsuboshi/Koyo timing kit was installed 20k ago on the old engine, those components were reused, with the exception of a new Mitsuboshi belt.

    At this point complete psychosis took over…

    I completely tore down the engine room harness in the as it was in a poor crispy state, with new convoluted tubing and imported directly from Japan Denka Vini electrical tape for the wrapping. Several connector ends were replaced/wires repaired. The ECU was taken out and I replaced all the capacitors with Japanese as a precautionary measure against future leakage. All ancillary engine brackets were cleaned if aluminum, and repainted matte engine black if steel. I also acquired many pieces of shiny west coast junkyard hardware from other Siennas to replaced my corroded bits. I would say less than 5% of the original hardware remains, as the van was an east coast car for the first 6 years and a Houston car for the next 6. I soda blasted what I could but with easy assess to 3 pick a parts with corrosion free parts, most stuff was just replaced including the entire intake plenium, anything with a cadmium coating, etc. It really annoys me how many times a car shows up with a “rebuilt engine” and the filth under hood completely obscures this fact. With my beloved Sienna, it will be clear that it is very much new.

    It goes without saying that all bolt-ons were either replaced or rebuilt. Near new Denso starter (junkyard score), Denso a/c compressor/drier/condenser/seals, Denso alternator, rebuilt the power steering pump, replaced the rack for a second time (first time I used new chinese, lasted less than a year) this time I rebuilt the original myself with MOOG ends. All new power steering lines, the return being flared and constructed myself.

    As it stands right now, the engine is finished, the under-hood area cleaned, all components cleaned/painted, cross-member newly repainted. Within the next day or two I should have the drive-train reinstated in my Sienna!

    • 0 avatar

      Wow with that level of work it is a pity you don’t have before and after 0-60 and quarter mile times.

    • 0 avatar
      SCE to AUX

      That’s fantastic, MatadorX. Hat’s off to you.

      The wiring harness is an important item you mentioned. I’ve had two Chrysler minivans die for cooked engine wiring harnesses; they weren’t worth fixing at the time.

    • 0 avatar

      Man and I thought *I* was OCD about using OEM stuff on my old Toyota. My hat is off to you sir.

    • 0 avatar

      I wasked going to suggest replacing all the seals and calling it good, but obviously this thing means a lot to you. I’m hardly one to talk with the money I’ve spent on my wagon. Good for you keeping the old girl going.

    • 0 avatar

      That’s awesome! I am very impressed with your work, what a great story!!!

    • 0 avatar

      You are f*cking insane. And I mean this as a compliment! Can’t tell you how envious I am. Hope you enjoy your all-but-new ride for another twenty years!

    • 0 avatar

      I am glad you intend to keep it til its natural death, because it’ll never pencil out money wise. But that is what separates a gearhead from a normal person, right? If after all this work, done with this attention to detail, the van does crap out, just stop and say a short prayer and put a .357 into the block and walk away. With the license plates. And play Sergio Leone music.

    • 0 avatar
      Kevin Jaeger

      I admire the work that has gone in to keeping this thing on the road.

      But somehow I think with this amount of resourcefulness and mechanical skills available the OP could be rolling in a vehicle that is much more, umm, interesting. I’m thinking a Mercedes W124 or maybe a near-classic Lexus.

      But if this Sienna is what interests the OP, who are we to argue?

  • avatar
    87 Morgan

    Wow, I strike my original comment from the record.

    In the future when asking for suggestions something along the lines of “I am really OCD, also a neat freak and perfectionist at the same time while combined with a strong desire to remain as OEM as possible”

    This would allow us to better answer your query. Either way, good on you for basically hand building/restoring your Toyota Van to most likely better than new.

  • avatar

    You sir have a sickness, but it will keep you out of trouble. Carry on

  • avatar

    Either put it back in as is or do the rebuild yourself with known quality parts and machining. You love this thing. Think about how you’ll feel driving it with a fresh quality rebuild (or short block you assembled vs. with a junkyard swap.

  • avatar

    I want to also point out the Solara as a worthwile donor. I had one of these and it had the same buttery-boat-like ride as the ES300-It was literally a poor man’s coupe Lexus. Outside sludge and O2 sensor issues on the Cali spec versions, the 1MZ engine was bulletproof. While you have her down, may I suggest the TRD Supercharger if you can find one? Though at that point, a rebuild would be advisable.

  • avatar

    My parents got a ’99 Sienna (in high trim, though I can’t recall the specifics).

    It was a great minivan at the time and is still pretty darn good – one of my friends is driving it these days, and I always liked borrowing it (since it was far faster and more fuel-economical that either of the vehicles I owned at the time).

    With all the work that’s gone into maintaining the OP’s example, I’d rebuild the engine and go for it.

    If the body’s in good shape, it should have another 150,000 miles left in it, easy, with all that work.

  • avatar

    I maintain two 1998 Siennas for a friend so I know a bit about these vans. The first one made it to somewhere around 230K miles before it started knocking badly. I suspect the oil-sludging problem (I haven’t pulled a valve cover yet to verify). It still runs but has at least two connecting rods with bad bearings now.

    So I bought a second, identical Sienna for $2K, with 200K miles on it. That is their primary vehicle now. But they tell me now it is making noises too (which I have yet to hear in person) so I’m worried about that one.

    Rebuild your engine or find a lower-mile engine to put in right now. That way, you can run it for another 100K+ miles without any issues.

    That’s my advice. Follow it, or not.

  • avatar

    I am completely in awe. I know I’m a bit older than normal but would you consider adopting me. I come with a 95 4Runner that would appreciate the same treatment.

  • avatar
    cimarron typeR

    Strong work!As a member of the sienna brotherhood, I’d kick in some e-dollars to get this van on the dyno

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