Even if test T-84 OPLOT had a engine failure could be a rectifiable issue as already its in widespread use in Pakistan and beat German, French and Chinese alternatives when chosen for Al-Khalid.
Ukrainian
KMDB 6TD variant engines power the T-80UD, T-84 OPLOT and the Al-Khalid. It's already being fielded in huge numbers in PA and Pakistan is in process of getting TOT for it.
A newer 1500HP 6TD-3 variant has been offered to Pakistan.
http://quwa.org/2017/02/21/idex-2017-pakistan-ukraine-sign-agreement-co-produce-engines-tanks/
It's a very good tank, issue with Thailand delivery happened because of unstable situation in Ukraine. In event of a Pakistan order it is likely that there will be alot of tech transfer and local manufacture in Pakistan.