2005 Toyota Sienna driving like I'm pulling a small trailer

Asked by Sep 09, 2015 at 12:19 AM about the 2005 Toyota Sienna LE

Question type: Maintenance & Repair

My 2005 Toyota Sienna has 148K miles on it and I've owned since new.  Van is well maintained, and many things have been serviced.  Also have installed new mass air flow sensor recently.  Problem:  Van's mileage is down on highway from about 26-27 when newer to now 21-22 on highway.  Best way to describe it is that it drives like I am pulling a 500-700 pound trailer.  The least bit of grade and it downshifts from OD to 4th gear (about about 70mph).  If on a nice Kentucky hill, it will even have to downshift to 3rd gear (and jump to 4K rpm) in order to maintain  cruise control speed.  Yes, all this is while on cruise control, but problem is still there with cruise off and me trying to hold constant speed with throttle.  Basically, it is constantly shifting back and forth between 4th and OD unless the road is almost perfectly flat.  It DID NOT used to do this and when newer it could actually accelerate in OD gear (5th).  Any suggestions?

2 Answers

94,965

Fuel pressure and flow, dirty injectors, transmission pressure may be dropping due to worn internal seals, weak torque converter, you may want to have the codes checked just to make sure nothing is in the memory.

I have run about 3 cans of Sea Foam and about 6 tanks with Marvel Mystery Oil thru to clean injectors. Last time my mechanic checked, there were no 'problem' codes being thrown. Did he maybe not look deep enough? Have not checked fuel pressure and flow. Have only changed tranny fluid once at about 80K miles. Fluid still now looks healthy.

Your Answer

Add photo

Related Questions

  • 2005 Toyota Sienna driving like I'm pulling a small trailer 2 answers

    My 2005 Toyota Sienna has 148K miles on it and I've owned since new. Van is well maintained, and many things have been serviced. Also have installed new mass air flow sensor recently. Problem: Van...

    2005 Toyota Sienna LE

    -

    Maintenance & Repair

  • 2005 Sienna Toyota - AC Blower 1 answer

    My front AC blower is shot. The rear AC blower still works. Is it possible to remove the rear blower and use it as the front blower? I use the van as a cargo van, so I really don't need the rear bl...

    2005 Toyota Sienna

    -

    Maintenance & Repair

  • Transmission issue on a 2003 Toyota Sienna 3 answers

    I have a 2003 Toyota van came to a stop light then started to go in the van wouldn't move just the RPM's went High wasn't slipping before this happened or anything could it be a filter or sensor o...

    2003 Toyota Sienna XLE

    -

    Maintenance & Repair

  • When to change the intake manifold gasket on 2005 Toyota Sienna? 2 answers

    I just changed the spark plugs on the 2005 Toyota Sienna and what a job that was! I see that on the upper intake manifold it has a red rubber gasket. Is it necessary to change this gasket? the ga...

    2005 Toyota Sienna LE

    -

    Maintenance & Repair

  • 2005 Sienna only blows heat while driving, not idling - what's wrong? 2 answers

    2005 Sienna only blows heat while driving, not idling - what's wrong? Blower always works, but it's only warm when driving.

    2004 Toyota Sienna 4 Dr CE Passenger Van

    -

    Maintenance & Repair

Search Toyota Sienna Questions

Toyota Sienna Experts

#1 Mik00000
Mik00000
Reputation 1,590
#2 Tom Demyan
Tom Demyan
Reputation 1,180
#3 dandyoun
dandyoun
Reputation 890
View All

Related Models For Sale

Used Honda Odyssey
212 Great Deals out of 20,906 listings starting at $1,900
Used Toyota Highlander
362 Great Deals out of 26,007 listings starting at $2,800
Used Dodge Grand Caravan
168 Great Deals out of 26,541 listings starting at $2,300
Used Toyota Camry
1,104 Great Deals out of 90,757 listings starting at $1,599
Used Chrysler Town & Country
273 Great Deals out of 16,152 listings starting at $900
Used Honda Pilot
390 Great Deals out of 22,299 listings starting at $1,500
Used Kia Sedona
112 Great Deals out of 8,966 listings starting at $2,200
Used Nissan Quest
63 Great Deals out of 2,759 listings starting at $2,499
Used Toyota RAV4
892 Great Deals out of 67,125 listings starting at $1,990
Used Toyota 4Runner
260 Great Deals out of 19,017 listings starting at $2,500
Used Toyota Corolla
860 Great Deals out of 70,584 listings starting at $1,874
Used Toyota Sequoia
137 Great Deals out of 5,468 listings starting at $1,500
Used Toyota Tacoma
473 Great Deals out of 41,586 listings starting at $1,995
Used Chrysler Pacifica
49 Great Deals out of 27,739 listings starting at $1,900
Used Honda CR-V
924 Great Deals out of 59,345 listings starting at $1,990

Used Cars For Sale

2017 Toyota Sienna For Sale
19,736 listings starting at $23,617
2016 Toyota Sienna For Sale
10 Great Deals out of 1,042 listings starting at $20,250
2015 Toyota Sienna For Sale
39 Great Deals out of 1,447 listings starting at $14,500
2014 Toyota Sienna For Sale
43 Great Deals out of 1,795 listings starting at $12,629

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.