There are 3 owner-reported engine complaints for the 2010 Lexus ISin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
While driving home in the freeway, I felt my car shake then a sudden loss of power. Then my CEL started blinking and my VSC lit. Got a code for engine misfire(P0302). Is250 has a lot of cases on engine misfires because of excessive carbon build up because of how the engine is designed. My car only has 108,000miles. Lexus released a Customer Support Program for this problem but it already expired. They only gave 9 years from date of purchase for it to be eligible for the free fix. It means they are aware of the problem but my 2010 car just missed that window but I am having the same problem many IS250 owners have. It is really unsafe when you’re driving in the freeway then it suddenly loses power. Hopefully this problem gets resolved by Lexus soon.
KNOWN BY LEXUS AS A COMMON FAILURE IN THE 2UR ENGINE IS THE VALLEY PLATE COOLANT LEAK. THIS IS A FAILURE THAT THE MAJORITY OF OWNERS IN THE FORUMS HAVE REPORTED AS WELL AS MY PERSONAL VEHICLE EXPERIENCING. CAN HAPPEN AS FEW AS 50K MILES. COMMON COST FOR REPAIR TO THE OWNER IS BETWEEN $2000 AND $3000. MINE HAS HAPPENED EVEN AFTER METICULOUS MAINTENANCE. *TR
ISFS YEAR MODELS 2008-2014 ARE AFFECTED THE VALLEY PLATE LEAK DUE TO THE FACT THAT TOYOTA/LEXUS UTILIZED THE IMPROPER SEALANT AND USED THE IMPROPER AMOUNT, LEADING TO THE HEAT EXCHANGER LEAKING COOLANT ONCE THE ORIGINAL, INADEQUATE SEALANT BEGINS TO DISINTEGRATE. THIS COULD CAUSE A CONDITION WHERE THE ENGINE COULD FAIL AND SOMEONE COULD GET HURT. FURTHERMORE, ALL ISFS WILL EVENTUALLY HAVE A CRACKED RH MANIFOLD ON THE #8 RUNNER. THIS CAN CAUSE A FIRE HAZARD IN ADDITION TO CARBON MONOXIDE POISONING. *TR
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026