Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1999 Toyota Sienna owners, lightly cleaned up (personal details are redacted by NHTSA).
My wife was driving on the florida turnpike with our sons (ages 3 and 1) in the vehicle. The engine light came on and the engine died. She coasted over to the side of the road. She stayed in vehicle and kept the boys in their car seats as she was along a major highway. A road side assistance vehicle pulled up behind her within a minute or two. He asked my wife what the problem was. She told him and he asked her to pop the hood. She did. He opened it and flames came out of the engine compartment. Neither he nor my wife knew or suspected a fire. No flames. No smoke. No smell. No heat. He yelled to my wife to get herself and the kids out of the car. She did and they were all unharmed. He put the fire out with a fire extinguisher. Obviously, my wife and children probably would have been killed had that road side assistant not been there. Fl highway patrol arrived. …
My van had first engine oil sludge problem at 32782 miles in March 2003. Finally Toyota paid the repair cost after many phone calls. One year later, on July 5,2004, I found that there is no engine oil left again during the middle of our family vacation trip (at 46000 miles). And blue smoke comes out from exhaust pipe again. Toyota couldn't fix the problem by clearing changing some parts. I request Toyota replace the defect engine.
Oil sludge.started blowing at stop lights and all startups.calling Toyota this week. This Sienna is in mint condition.we bought it for safety and dependability for our 7 week old son.now we'll see if Toyota stands behind it.this is our 1st Toyota,but there are 7 Lexus/toyotas' within our families.this engine is damaged and from what we have read,expect a complete new one.
Engine of 1999 Toyota Sienna (van) had sludged engine oil in July 2002, dealer rebuilt engine. In November 2003, oil pump failed on same vehicle. Dealer contends the failure of the oil pump is not related to the engine oil gelling/becoming sludge. Since engine was rebuilt, owner has changed oil every 3,000 miles and has receipts to prove it.
1999 Toyota Sienna is sitting in driveway for past 2 months with seized engine due to this "oil sludging" problem. Cost to repair over 6000 from dealer. Certified mail sent 2/18/04 to Toyota motor sales in torrance, ca., with copy of maintenance records showing oil filter & oil changes.
I have a Toyota Sienna 99 and my check light coming out and start to smoke so I find the engine do the oil be sludge, I want to know if is some way of Toyota fix this problem for me whit out charge because is a manufacture problem.
While driving vehicle consumer states" noticed blue smoke coming from exhaust. Took to dealer and they performed a engine overhaul. Consumer feels engine May seize up. Please provide any further information. Ts
Waiting to hear from Toyota on our oil sludge engine failure problem. We are gathering the oil change receipts and were 1st told we did not maintain the vehicle. Now seeing that we are not alone with this issue.
I am reporting another Toyota sticky accelerator pedal. Our 1999 Sienna minivan has had 3 incidents of stuck accelerator, the most recent was jan. 21, 2010. I believe it has become "stuck" between 40 and 45mph. Other incidents were in summer (cannot remember date) and October 2009. The 1st incident was brief and corrected quickly by pushing down on the pedal to "free it", the 2nd incident required braking and putting the car in neutral and shoving the pedal with my foot to the left and right to free it up. I was able to drive the car to the shoulder, turned the car off and then the pedal seemed to work OK, although a bit sluggish response. Our mechanic fixed the throttle body and the car has not had another incident until last week. …
At 30,874 miles our van started blowing blue smoke. We took it to the dealer who told us that the engine had "sludged up" and would require at least $3,000 to fix. We were also told that it wasn't covered by warranty (3 year/36,000 miles). We asked why and were told that the sludge could only be caused by lack of maintenance (oil changes). We produced receipts showing oil changes were done, but the company still won't cover the work under warranty. We have spoke to the Toyota's regional customer relations administrator and gone through the Toyota provided arbitration proceedings to no avail. We went to the internet and searched under "Toyota Sienna sludge" and found dozens of other people having the same problem with their siennas and warranty coverage. We believe the is a defect in the Sienna v6 engine causing the sludge build up.
NHTSA investigations
Engine seizure
Engine complaints in other Sienna years
Frequently asked questions
How common are engine problems on the 1999 Toyota Sienna?
NHTSA has 39 complaints about the engine & cooling of the 1999 Toyota Sienna, 18% of the model year's 215 complaints. The component named most often is engine › gasoline (19 mentions).
Is there a recall for 1999 Toyota Sienna engine problems?
No. NHTSA lists no engine & cooling recall for the 1999 Toyota Sienna, though it has 2 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1999 Toyota Sienna engine problems start?
Half of the complaints with a recorded mileage happened before about 79,000 miles.
Is it dangerous?
Owners linked 0 crashes, 1 fire and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.