Hi
Based on the serial no, this truck shipped 2021 which may mean depending on hrs that it is still within warranty. Please contact Conmbilift before doing any repairs to the engine to confirm if warranty or not as you may void the engine warranty.
The link to the engine callout form is https://warranty.combilift.net/combilift-engine-callout-request/.

There is no charge to use the callout or technical support. For general techical support please use the following link https://warranty.combilift.net/technical-support-form/

All links are at the bottom of the main combilift.com web site and the forms work on phones or PC's.

Thanks,
Richard