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Engine coolingPart report

2008 Toyota Sienna Engine cooling Problems

Complaints
12about this part
Share
3%of 429 total for the year
Median mileage
35,550miles
Trend
Not enough dataFewer than 15 complaints, too few for a reliable trend.

NHTSA recorded 12 complaints about the engine cooling of the 2008 Toyota Sienna, 3% of the 429 complaints for this model year. Where a mileage was given, the median is 35,550 miles. 1 a fire, according to the filers.

Fewer than 15 complaints name this part, so treat the figures as a rough indication only.

Example complaints

Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.

“At highway speed, all lights flicker on then lost all power.......oilline had leaked on alternator belt causing loss of power. Luckily power loss prevented engine damage from oil leak. We had not been notified by Toyota about the oil line problem or recall.....only after a local garage fixed the line did I find out about the recall....I would had it replaced earlier if I had been notified.”

NHTSA complaint #10447848, filed 2012-02, 98,000 miles

“Piston slap on Toyota 3.5 l v6 since new. Very loud when cold in cooler temperatures..ca arbitrator agrees with Toyota that this is normal for this engine. I cannot sell this car with this noise but Toyota doesn't care. Toyota has had a few complaints but no failures yet. Piston slap wears the piston prematurely and could in my opinion lead to failure. This is my 2nd complaint to you people for the same issue.”

NHTSA complaint #10308446, filed 2010-02, 67 miles

“Early am on 6/1/10 I was driving to my cabin in the country and heard a soft popping sound, stopped my car and smoke began flowing out all opening around the hood, when I looked under the car I saw fire falling to the road. I went to the passenger side and opened the door only to find that area filled with toxic fumes, shutting the door I realized all was hopeless except to get away from the vehicle. Within seconds my car was engulfed in flames. I ran as fast as I could to get help. Had I been less alert, inactive, less proactive I would have probably died. …”

NHTSA complaint #10335997, filed 2010-06, 10,000 miles

“In the summer of 2009 my Toyota 2008 Sienna xle awd engine speed slowly started to climb without my foot on the gas pedal. I don't remember the exact sequence of events that followed but I believe I placed it into neutral, stopped, placed it into park (automatic transmission) and turned the engine off then on again. After that the engine responded only to my actions on the gas pedal. It did occur to me that the pedal could have been caught under the floor mat so I checked its position and it was some distance from the pedal and could not have been the cause. …”

NHTSA complaint #10336591, filed 2010-06, 15,000 miles

“Driving my 2008 Toyota Sienna and it felt funny and I heard some rattling from under the hood. No idea what the problem was but I knew that something was definitely wrong. I checked the oil and the dip stick was completely dry! I put in a few quarts of oil and it came out all over underneath the car as I was driving. Had it towed to the dealer- they told me it was a faulty rubber oil line. I looked it up online and see that Toyota had not yet issued a recall but is replacing it in some vehicles. The 2008 Toyota Sienna is not mentioned - but clearly should be. …”

NHTSA complaint #10320501, filed 2010-03, 35,550 miles

Related service bulletins

Engine cooling: other model years

YearComplaintsShare of year
201311%
201210%
201161%
201042%
200942%
2008123%
2007144%
200640%
2005172%
2004462%
200366%
2002169%
20012413%
20006618%
19993918%
19983311%

Other parts of the 2008 Toyota Sienna

Body and structure
117 complaints
Vehicle speed control
51 complaints
Electrical system
45 complaints
Brakes
43 complaints
Engine
39 complaints
Other or unknown
38 complaints
Transmission and drivetrain
38 complaints
Steering
33 complaints
Electronic stability control
29 complaints
Tires
19 complaints
Air bags
14 complaints
Latches, locks and linkages
13 complaints

← All problems reported for the 2008 Toyota Sienna

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 28, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology