Toyota Thinks It's Found Source of NASCAR Cup Engine Woes

Toyota Racing Development general manager Tyler Gibbs says the multiple engine problems Toyota has experienced this year appears to have been caused by faulty valve springs.

Martin Truex Jr.’s Toyota exited this past Sunday night’s Cook Out 400 at Richmond Raceway with engine failure, the fifth one this year by a Toyota entry. The other four occurred before the two-week break in Joe Gibbs Racing Toyotas driven by Truex, Christoper Bell and Ty Gibbs.

Prior to the Richmond event, Tyler Gibbs said each engine had been examined, the cause of the failures determined, and the OEM felt comfortable the issue resolved. Then Truex’s Toyota went to the Richmond garage with an engine failure after 250 laps.

Tyler Gibbs said Thursday the engine failure in Truex’s Toyota at Richmond was similar to Bell’s at World Wide Technology Raceway at Gateway in June.

“The root cause seems to be some inconsistency in the quality of our valve springs,” Gibbs said, noting the OEM was working with its suppliers to correct the issues.

“We sent a TRD ‘fire-team’ from our Costa Mesa engine shop to make tuning updates to all our engines heading to Michigan this weekend. We are confident that this remediation step will give us the durability margin we need.

“We had only one failure in 2023. TRD takes full accountability for the issues we have had this year, and we have fallen far short of what is acceptable.”