Toyota Sienna Engine Problems

new2dieselnew2diesel Member Posts: 148
I have a 2004 XLE with approx 40,000 miles and I have a very persistent spark knock that is anoying. Does anyone know how to remedy this? I f I remember you used to be able to retard the timing just a touch and eliminate this one some vehicles. Would this work on this one and if so how can I go about doing it?

I have also noticed that these vans eat tires. I'm on my second set and they are already wearing unevenly (after alignment) and making the dreaded wop wop wop noise ( yes I rotate them and keep them inflated firmly).

Thanks for your help.


  • taxesquiretaxesquire Member Posts: 681
    I have an '04 with similar mileage, but have not experienced your problems - not with knocking and not with tires. We are on our 2nd set.

    In a way, I can understand if these vehicles go through tires quicker than other vehicles b/c of friction. Just like sportscar tires wear out more quickly b/c they are made to grip the road and, thus, increase friction, the weight of the minivans should give more friction to the tires than other vehicles.

    Good luck with your issues.
  • tanzatanza Member Posts: 1
    My 2000 Sienna XLE has 84K miles on the odometer. I took it in for the "big" service. Now it has harsh engine vibration at idle while the car is in gear (i.e. stopped in traffic). The engine is also noticeably louder when it shifts into OD at freeway speeds (55-65 MPH). Finally, the gas mileage has dropped about 2 mpg. My dealer can't seem to figure out what the problem is. They changed two engine mounts which isolates the vibation somewhat but there is still engine vibration.

    Has anyone experienced this problem? Can someone offer some advice? I like my Sienna but the vibration is starting to get on my nerves.
  • caravan2caravan2 Member Posts: 198
    I was driving someone else's 2006 LE with 25K miles on it. When I start it, the sound comes like slippage of serpentine belt. Then it goes away. Is this normal?

    Second, Service RQD was on constantly. He said, it has to be reset everytime after oil change is due. Is this normal also.
  • jaccordjaccord Member Posts: 2
    There is a TSB on the nocking I took mines to the dealer
    and got fix at no charge.
  • johnsonjhnjohnsonjhn Member Posts: 2
    I had recently had a check engine light diagnosed as a faulty ECM. This module is very expensive ($1700)and I was looking for a replacement.

    Any ideas here?

    What impact is there for not replacing this module as the car is running okay?
  • nhzeronhzero Member Posts: 1
    Every time I get into my Sienna to go somewhere, after a few seconds it will make a weird noise that I can feel through the pedal for about two seconds. It seems to be speed triggered, not time triggered, and it takes a little while, it's not immediate. It also doesn't seem to be related to whether I back out or pull forward, or have anything to do with whether I use the brakes or not.

    It reminds me of those old toy cars that had a little plastic strip that touched the gear to make a noise. After it does the noise (EVERY time I go somewhere), it won't do it again until I turn the car off and go somewhere else. I haven't tried putting it back in park after it does the noise to see if it does it again, but I am completely confused as to what it could be. Any ideas? I am hoping it's not something expensive in the transmission.
  • mnrep2mnrep2 Member Posts: 200
    This sounds like, your ABS braking system "Self Test". Most cars exhibit this behavior today. Some more loudly than others. Don't worry, no problems ;)
  • new2dieselnew2diesel Member Posts: 148
    Do you know the TSB number so I can refer to it? Also how long did the repair take and did it work?
  • bearcrkrdbearcrkrd Member Posts: 167
    Anti-Lock Brakes it is! It is really noticeable in the Sienna. My last vehicle, a 2005 Tacoma was the first vehicle I had with anti-lock. It made a whoosh or shwoosh sound when first started up and you took off in the driveway. About 5-8 seconds after you started moving. Does it in reverse, too.
    We had snow a while back and I had some kids in the car who asked me to go sideways on the ice. You should have heard the anti-lock brakes then. Sounded like a little motor running when the tires slid when I applied the brakes.
  • jaccordjaccord Member Posts: 2
    Hi here is The tsb Im not sure how long it took I drop it in the morning and then pick it up at night.
    Engine "Pinging" or "Knock Noise"
    TSB EG055-06 September 6, 2006.
  • ejk3ejk3 Member Posts: 1
    I have 2001 Sienna of which mileage is 78K now.
    I took it to local auto shop to get maintenance 3 days ago.
    At that time, mechanic said my car's oil level was too low
    even though I changed it just a few months ago.
    The next day, he called me and said that one piston was broken and unless I change engine, my car will die on the road. And he said he had seen lots of similar problems in other Siennas and Avalons.
    I picked up my car today and they charged 1600 dollars.
    Can this case be covered with oil gel settlement?
    And I'm not keeping any oil change receipts. Can I get reimburse for this? :cry:
  • mlowmlow Member Posts: 1
    My 2004 Toyota Sienna has developed a noise when started, especially when cold. It is quite a loud noise, similar to valves clacking, but it goes away and we don't hear it once the engine is warm. the dealer does not seem to think this is a problem but it did not make this noise when we bought it over even a few weeks ago? I don't like it - anyone else have a similar issue now or in the past?
  • avital123avital123 Member Posts: 2
    I had a very similar problem witha 98 Nissan Quest Minivan. It had a loud clank noise as it the valves were clacking. When I first took it to the mechanic, they replaced the exhaust manifold seal. Noise went away but came back a week later. I took it again and it turned out that the exhaust manifold assembled to the engine block had warped. Some of the bolts holding the manifold to the engine had broken off as well. As the engine heated up (around 3 - 5 minutes) the warpage would straighten up and the noise would go away. I replaced both front and rear exhaust manifolds and the vehicle is working very well.
  • avital123avital123 Member Posts: 2
    I have a 1998 Nissan Quest Minivan. A year and a half ago after travelling 70 miles at 65 mph using the cruise control, the transmission shifted down to 3rd gear for a few seconds then shifted back to overdrive. As I kept driving, it did it more often. I returned the 70 miles and had to really slow down as the transmission shifted even as down as 2nd gear. The mechanic could not detect any issues using the computer. I used it 18 months in the city without any problems at all. This weekend I travelled and again after 70 miles, it started shifting down from overdrive to 3rd gear. On my way back, I was travelling against the wind and had absolutely no problems. It appears as if it was heating up but the wind was cooling down. I have been driving it around in the city and again, absolutely no problemas. Has anyone experienced the same issue? Should I add a transmission radiator or should I give up and replace the transmission?
  • fulcrum81fulcrum81 Member Posts: 9
    I was testing drive a sienna xle. It's very quiet on local road. But when I tried to accelerate, the engine sounds very noisy, not as rhythmic as odyssey's engine. Anyone noticed this?

    Also, on the highway, the sienna seems as noisy/quiet as odyssey...
  • ateixeiraateixeira Member Posts: 72,587
    I think at cruise it's quieter.

    The 3.5l is louder than the old 3.3l because it uses a timing chain, but then again so does Honda. Plus, that means less maintenance down the road.

    Also, for the 3.5l, normally only one opening in the intake is used. At more than half throttle, or over a certain rpm, the 2nd intake path is opened for more power, and yes it makes more noise while that path is opened.

    Toyota added more insulation for 2007 to compensate for the extra noise, but at full throttle the engine asserts itself nicely.
  • nilionnilion Member Posts: 2
  • ateixeiraateixeira Member Posts: 72,587
    First off, the 2GR engine now uses a timing chain, which is a bit noisier but more durable and more economical than a timing belt, which usually have to be replaced every 60k miles.

    The catch is timing chains are indeed noisier, so Toyota added some extra sound insulation in the firewall and in the door jambs. I have a picture of it and you can see it below.

    Now, about the increase in noise at certain RPM - this engine also has 2 intake paths. Normally one is open to minimize intake road, but when the throttle is more than half way down and above a certain RPM the 2nd path opens to get maximum power.

    You might be experiencing that valve opening and closing, effectively doubling the intake roar. And of course it varies according to RPM and throttle position.

    FWIW, I don't think the noise is that bad. I've actually modified mine so that both intake ports remain open all the time. A set of vacuum tubes operates these and a simple mod leaves them both open all the time. I'm basically trading off a bit more noise for better throttle response, less hesitation, and (some say) better gas mileage.

    PS I should note that the older 3.3l engine also has the dual port intake, but it uses a timing belt.
  • nilionnilion Member Posts: 2
    Thank you ateixeira - your explanation and picture are very much appreciated and, I believe, an accurate assessment of the humming vibration issue.
  • caravan2caravan2 Member Posts: 198
    [quote]I've actually modified mine so that both intake ports remain open all the time[/quote]

    How do you that? Does this really improve gas mileage? If so, by how much??

    Does this modification effects warranty? Did you do it yourself?

    I have 3.5 engine.

  • ateixeiraateixeira Member Posts: 72,587
    It's fairly well detailed here:

    The funny thing is that it almost didn't make sense to me. I can understand that freeing up the air intake would reduce hesitation and increase power under certain circumstances, but I didn't believe the improved mileage claim.

    Thing is, I just can't argue with results. I drove to the beach this weekend and averaged 30.6mpg for the (all highway) trip. Yowsah. :)

    That's better than I got doing the same trip in my Miata!

    And we had 4 people, a dog, a little bit of luggage, and the A/C was on the entire time (DC summers in July are hot/humid).

    I can't say exactly how much it improved my mileage because I've only had the van for 1700 miles. I did wait to do this until after the 1000 mile break-in.

    The mod is very, very simple. You disconnect two vacuum hoses and re-route one to another location. I took the additional step of getting caps so that everything was sealed nicely.

    Does it affect the warrranty? I'll answer "maybe". It's not stock, but it's very easy to reverse and there would be no signs of any mods. Plus, past half throttle the intake operates like this anyway. This just leaves it in that double-intake-path mode all the time. You don't have to wait for the vacuum tubes to operate and suck the 2nd intake path open, hence some people say it hesitates less (note I did not notice any hesitation prior to the change).

    So this is your call. If you want to try it, note your mileage on a certain trip. Then, take that same trip again after the mod, and see if you notice a difference. The site claims a 1-2mpg improvement. I seem to observe about that much improvement, but again, my engine is green and breaking in, and it might have improved even without this mod.

    Trade-off? More noise. My wife noticed it once, but we got used to it pretty fast, and I don't want to give up 30+mpg plus quicker throttle response, so to me it was worth it.
  • siennaswedensiennasweden Member Posts: 7
    Does any now if the sienna can be converted to run on etanol (E85)fuel?
  • ateixeiraateixeira Member Posts: 72,587
    Anything's possible, the question is cost. I'm sure it would cost far more than it's worth.

    Plus, running on E85 actually costs more than running on gas.

    So you'd be spending money in order to be able to spend even more money.
  • siennaswedensiennasweden Member Posts: 7
    Well not in sweden, here the E85 is much cheaper about 30%.
    the regular 95 octane is about 12 swekr and the E85 is 7.50 swekr.
  • ateixeiraateixeira Member Posts: 72,587
    Cool, didn't know that.

    Here the savings are very small, and you get less mileage so it actually ends up costing more to operate.
  • newtovansnewtovans Member Posts: 3
    In the link you provide, the author states that the valve opens at 3200 RPM and over 30% throttle position. So this might not be the source of the humming noise between 2200 and 2500 RPM. I too have a 2007 Sienna which is very quiet below 2200 RPM, but hums/buzzes in the 2200 to 2500 RPM range. A long time ago, I had a Sentra SER make this sound, and it turned out to be the exhaust resonator which when replaced, fixed the noise. My Sienna noise is not so loud as to be bothersome, but I think it probably has to do with the exhaust system vibrating at that RPM due to resonant frequency response. Vehicle manufacturers design their exhaust systems so that they minimize resonance at most of the RPM range, but slight variations from car to car means that some will be louder than others.
  • fccn75fccn75 Member Posts: 2
    The SER was a very nice car: '92? 2.0, 140hp for the time was fantasitc!

    New to this site and glad to have found it after all this time googling on the humming issue with '07 Sienna LE without substantial results.

    Have 1700 miles and experienced the same exact issues: humming/moaning @ 2300-2500 rpm under load such as accelerating lightly but not enough to drop to the next lower gear. Especially noticeable on long stretch of inclines. The sound is very accurately described in your post - almost like a resonating exhaust vibration due to a resonate frequency in the narrow range of rpm. Don't know about the rest of the owners, but I find it very annoying when it does hum. Sounds almost as if I modified my exhaust system - and droning!

    I tend to lean toward the exhaust noise as opposed to the intake noise especially as described the VSV takes on >3200 rpm. Reminds me of my late '85 corolla gts (redlines at 7500rpm) where it would operate the second set of intake valves after 4200 rpm.

    Needless to say, I brought the van to the dealer for diagnostics and they were unable to find any problems. They informed me that they were unable to duplicate the noise which I had confirmed with one of mech. on a test drive. I guess this means that the noise is normal due to a design issue/flaw and that not too many drivers notice it.

    I'm glad to find out that there are owners that experience this noise and that this "problem" does exist. Now what to do about this?

    Wondering perhaps additional isolation engine mounts or something in the exhaust?

    Anyone knows of TSB regarding this?
  • siennamisiennami Member Posts: 116
    So that's why the 07 sounds so much louder? I was wondering about that when I test-drove the CE. I noticed that it seemed much louder than the 00 LE I drove a couple of years ago. One thing I've noticed is a little "hesitation" when I turn a corner. It could be my driving habits, but it seems a little weird. I've tried to be a little more conservative in my driving habits with this vehicle because of gas price concerns (you know, no jack rabbit take-offs, etc.), so I'm wondering about that "hesitation".
  • ateixeiraateixeira Member Posts: 72,587
    The 2GR is louder because it uses a timing chain, vs. a timing belt. Chains are noisier and have more reciprocal mass, but they don't have a service interval and are far less likely to break.

    Toyota compensated by adding extra insulation on the firewall and under the door sills, so while cruising my Sienna is still very quiet.

    Under full throttle it definitely asserts itself. But I like that. :shades:

    The hesitation may be the two-path intake. There's more information about that (and how to modify the intake if you are so inclined) here:
  • caravan2caravan2 Member Posts: 198
    I hear groaning around approximately 2k RPM? After that either it goes down or engine noise is so much, it seems it is lower....

    Is this normal for Sienna?
  • fccn75fccn75 Member 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 Member Posts: 198
    So, does it mean that some have it and some not?

    I'm going to test drive a couple and see....
  • ateixeiraateixeira Member 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 Member 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 Member 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 Member 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
  • lweekslweeks Member Posts: 12
  • jjoseph2jjoseph2 Member Posts: 18
    I have a 2002 Sienna with 80,000 miles. Check engine light just came on .Any ideas?
  • ateixeiraateixeira Member 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.
  • jjoseph2jjoseph2 Member Posts: 18
    Thank you for your help. It was just a loose gas cap. After 100 Miles it reset by itself.
  • ateixeiraateixeira Member Posts: 72,587
    Glad to hear it was minor.
  • hbandurskihbandurski Member Posts: 7
    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.
  • rob105rob105 Member Posts: 1
    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 Member 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 Member 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 Member Posts: 10,706
    The heat shield you removed was probably there to prevent melting of the plastic parts........Radiator shoud, fan blades, etc.
  • zakkizakki Member 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 Member 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 Member 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 Member 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?
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