Second language (L2) production can take on the form of an interlanguage, a relatively stable system bearing the nature of both the native language (L1) and L2. Within such a system, acoustic-phonetic components of a syllable are known to bear interlanguage characteristics, but how do these interlanguage components interact within the syllable? The present study investigates temporal patterns of L1 and L2 in interaction within a syllable. Audio recordings were made of English stop-vowel syllables produced by native speakers of Mandarin who were fluent in English (ChE). Native English productions (AmE) of these syllables, and native productions of comparable Mandarin (ChM) stop-vowel syllables were also recorded. Temporal measures included stop closure duration, voiceonset time (VOT), vowel duration, and syllable duration. Results show that the internal timing of syllable components in ChE productions often deviates from ChE in the direction of AmE, with the closure duration, VOT, and vowel duration being intermediate to ChM and AmE. These temporal deviations of individual components were also compensated by temporal adjustments of other components in the syllable, maintaining a balanced distribution between the consonant and vowel. These findings are discussed in the context of previous research on interlanguage behavior and the gradual process of acquiring a target language.