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Toyota Sienna Engine Problems



  • fccn75fccn75 Posts: 2
    Based on the comments I've read in this forum, this exhaust groan in that rpm range affects a few owners including myself.

    Perhaps more will chime in regarding this noise. And hopefully with more comments comes recognition of this annoying sound so a technical service bulletin will be issued for additional sound/mechanical isolation requirements.
  • caravan2caravan2 Posts: 198
    So, does it mean that some have it and some not?

    I'm going to test drive a couple and see....
  • ateixeiraateixeira Posts: 72,587
    While you do hear engine noise when you gun it, I'd still say the Sienna is probably the quietest vehicle I've ever owned.

    Perhaps it's just that - road noise is very muted, so you hear more engine noise.

    I say crank up the tunes! Nothing 100 decibels of DMB can't fix. :shades:
  • caravan2caravan2 Posts: 198

    The noise does not bother me. If everyone is getting this, then this how is designed to work. I just wanted to know if my engine have problem.
  • richw1richw1 Posts: 2
    I was glad to hear the Sienna engine sounds I have noticed since the beginning are normal. I have a 2005 Sienna Limited and since the beginning, from the drivers seat only, between 2000 and 2500 RPM (where the engine lives most of the time!) the engine generates a sonorous booming sound. My wife doesn't notice it even while driving, and it is not nearly as pronounced on the passenger side. I have decided it is one thing I have to live with, but as one post said, the Odyssey, which we test drove, had a much better engine sound. The Sienna is a good reliable appliance for the family; noisy engine, lousy electric seat position/comfort for a taller person, awful stereo...but all that aside, a great family vehicle....
  • lweekslweeks Posts: 12
    My symtoms exactly but never once warmed up. left over night 5 times they acknowledge the noise though. mechanic said there was a notice that it might be the injectors,& re- flashed the computer, it changed nothing, but now i get 10%better gas milage.they also changed the exhaust off motor, because the exhaust is double walled & may be seperating, still the same. Now with 96,000 kls on my 2004 sienna , I,m screwed lloyd
  • I have a 2002 Sienna with 80,000 miles. Check engine light just came on .Any ideas?
  • ateixeiraateixeira Posts: 72,587
    Do you have an OBDII scanner? Maybe a friend has one?

    The code will tell us more. Could be a loose gas cap, a bad 02 sensor, or something more serious.

    I'm in the DC/MD area if you want to borrow mine.
  • Thank you for your help. It was just a loose gas cap. After 100 Miles it reset by itself.
  • ateixeiraateixeira Posts: 72,587
    Glad to hear it was minor.
  • Take a look at this message where we are discussing this weird noise and see what a dealer and toyota engineering said to one of the sienna owners.

    In my case my wife (and now myself) can't stand this noise - weird noise is weird noise - it shouldn't be there.
  • I have a Toyota Sienna 2007 with 19K miles. The engine seems much louder from when I first bouhgt the car. When it start from a cold start I can hear a clicking sound till the engine warms up. The dealer has told me this is normal and it is the fuel injectors. Once the car warms up I don't hear it as bad. Has any one else experienced this? Thanks.
  • philtaophiltao Posts: 1
    Just bought a Sienna Le 2008 w/ 30k on it from a local dealer. There seems to be engine noise somewhat like a diesel engine, which I've ridden on other Sienna le 2005 with the same mileage with no such noise. Also on my Le 2008, I can hear the gear shifting once or twice before reaching 35mph. Other times, when I was driving very slowly and stepped on the gas, the van seemed to be more like on neutral with loud noise and than it caught the drive gear again. What's wrong with the engine?? Help?? Should I take back to the dealer to check?? or what??
  • da763da763 Posts: 14
    I had the oddest thing happen a week ago. I started hearing a horrible racket from the engine which sounded like it was rev'ing like crazy, yet the tach needle never moved. So, I popped the hood to find that a heat shield that was supposed to be attached to the exhaust pipe leading from the manifold on the front cylinder bank, had sheared off of the two screws holding it to the pipe and had fallen forward into the engine fan.

    After the engine cooled down, I reached down and removed it. Since there's quite a bit of room between the pipe and any other component, unless this is covered by a recall or TSB, I'm not inclined to fix it.

    Has anyone else had this happen?
  • wwestwwest Posts: 10,706
    The heat shield you removed was probably there to prevent melting of the plastic parts........Radiator shoud, fan blades, etc.
  • zakkizakki Posts: 1
    I have a 2007 Sienna with 49,000 Km, and have the same problem. Dealer said that the noise is due to a variable valve gear bolt being too close to the front engine cover and had agreed to replace the bolt with a updated one. Apparently, Toyota issued a TSB on this issue. My van is still at the dealership undergoing repair. Will let you know how the repair worked out.
  • buckynixbuckynix Posts: 1
    Hi, We've got the same problem with the heatshield falling off into the fan on our 2004 Sienna LE. I'm wondering if anyone has removed this shield and if any issues were noted. I'm concerned about melting the fan blades. Please let me know if you've tried to run without it. Thanks.
  • wr31wr31 Posts: 2
    I have the same car and had the exact same thing happen last week. I also removed the broken shield to eliminate the noise, but am interested in replacing it. Did you ever replace yoursn or find out if Toyota recalled the part?
  • wr31wr31 Posts: 2
    Did you ever replace this part? I had the same thing happen last week on our 04 Sienna LE - I removed the shield and am driving without it now. So far, no problems, but am concerned about the heat. What did you do?
  • da763da763 Posts: 14
    No, I haven't replaced it. I've kind of taken a wait and see approach. I check the pipe and fan area about once a week and I can't see that there's been any further damage from running without the shield. There's about 8+ inches of clearance between the pipe and the fans, and there are two fans in the area, but nothing else close, so I think it has more than adequate cooling to get by.

    I would be interested in the response you get from Toyota if you take it in to be repaired. Since I'm long out of warranty, I'm leery of this leading to some much larger and more expensive repair.
  • That is a question I'm a little curious about. IF I ever have an engine failure [128k, runs great, lived it's entire life on Mobil I] I wonder if it would be possible to fit a 3.5 where the 3.0 was without too much difficulty.

    Any Toyota techs out there heard of such a thing?+
  • ateixeiraateixeira Posts: 72,587
    I seriously doubt it.

    The 3.0l was the 1MZ, the 3.3l was the 3MZ. Those are probably related, and you MIGHT be able to swap them out.

    The new 3.5l is a 2GR engine, totally different engine family.

    It might be easier to drop in a Ford V8.
  • wwestwwest Posts: 10,706
    The problem might really be getting the new engine's control ECU to speak "english" to the "old" LAN, Local Area Network, especially the old transaxle.
  • kat2800kat2800 Posts: 23
    I am having the same noise when I go between 50-65mph. If I take my foot off the pedal it stops immediately. Seems to be more when I am accelerating like on an incline or on ramp to the highway. I just bought this 07 LE 7pass Sienna - literally 48 hrs ago. I didn't drive it on an incline when I test drove it. Should I ask them to look at the heat shield and see if it is lose?
  • I'm glad it is only a rhetorical question--I'm hoping for a long life for this vehicle, which, so far, has been the best I've ever owned. From the looks of some of the posts here, my '01 might be better than a new version.
  • ateixeiraateixeira Posts: 72,587
    Nah, my 07 has been flawless. People seek out forums like this to complain, you always hear the worst-case scenarios.

    How many people hop on the internet to say "no problem here" on their vans? Noone. Only existing members who subscribe to the threads already, and good samaratins trying to help.
  • so i just passed 1,000 miles on my 2010 le and i am thinking of doing a quick oil change to get out " the fine bits"

    when did you do your 1st oil change and did you take it to the dealer or your "local guy"?

    did you use regular oil or synthetic and are you happy or do you wish you did the opposite?

    thanks for your advice
  • ateixeiraateixeira Posts: 72,587
    I did my first at 5k miles and the oil really wasn't that dirty. No metal shavings on the magnetic drain plug, either.

    I'm using regular dino oil, thin stuff - I think 5w20.
  • I have an 07 Sienna LE with 32K on it. I have had no trouble with it starting until today. We got out of a store and it would try to turn over but couldn't start unless it was jumped. After shutting it off for a few hours I had to jump it again. The battery says it is fully charged and when I turn the key the lights, radio, windows, etc all work fine. Once it is running it runs well. Any suggestions? I bought it used and it is still under the 90 day/3500 mil warranty from the dealer. Would this be covered?
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