We report results from a deep Jansky Very Large Array ( JVLA ) search for ^ { 12 } CO J = 1 - 0 line emission from galaxies in a candidate galaxy cluster at z \sim 1.55 in the COSMOS field . We target four galaxies with optical spectroscopic redshifts in the range z = 1.47 - 1.59 , consistent with the likely redshift for the candidate galaxy cluster . Two of these four galaxies , ID 51613 and ID 51813 , are nominally detected in CO 1 - 0 line emission at the 3 - 4 \sigma level . We find CO luminosities of ( 2.42 \pm 0.58 ) \times 10 ^ { 10 } K km s ^ { -1 } pc ^ { 2 } and ( 1.26 \pm 0.38 ) \times 10 ^ { 10 } K km s ^ { -1 } pc ^ { 2 } , respectively . Taking advantage from the clustering and expanded 2-GHz bandwidth of the JVLA , we perform a search for emission lines in the proximity of optical sources within the field of view of our observations ( 60 ^ { \prime \prime } ) . We limit our search to galaxies with K _ { \mathrm { S } } < 23.5 ( AB ) and z _ { \mathrm { phot } } = 1.2 - 1.8 . We find 2 bright optical galaxies , ID 51207 and ID 51380 , to be associated with significant emission line peaks ( > 4 \sigma ) in the data cube , which we identify with the CO 1 - 0 line emission . To test the reliability of the line peaks found , we performed a parallel search for line peaks using a Bayesian inference method . Both CO line emitting candidates are identified with probabilities of 13 % and 72 % that there are line emitting sources in each case , respectively . Monte Carlo simulations show that such associations are statistically significant , with probabilities of chance association of 3.5 % and 10.7 % for ID 51207 and ID 51380 , respectively . Modeling of their optical/IR spectral energy distributions ( SED ) indicates that the CO detected galaxies and candidates have stellar masses and star formation rates ( SFRs ) in the range ( 0.3 - 1.1 ) \times 10 ^ { 11 } M _ { \odot } and 60 - 160 M _ { \odot } yr ^ { -1 } , with star formation efficiencies ( SFEs ) comparable to that found in other star-forming galaxies at similar redshifts . By comparing the space density of CO emitters derived from our observations with the space density derived from previous CO detections at z \sim 1.5 , and with semi-analytic predictions for the CO luminosity function , we suggest that the latter tend to underestimate the number of CO galaxies detected at high-redshift . Finally , we argue about the benefits of future searches for molecular gas line emission in clustered fields with upcoming submillimeter/radio facilities .