Probably nothing to do with the replacement clutch. The engine light comes on when a fault is developing or when an engine needs attention/servicing. If your light is coming on and going off intermittently it is probably time to have it checked over serviced . This will lessen the likelihood of serious damage ocucoccurring in future
Might want to recheck your head gasket is seated properly and that all cylinder head bolts are torqued properly. Sounds like you have oil mixing in with your coolant.
I got this free Pdf manual from reliable-store for free and I don't think Ive visited a mechanic or fixya for help for more than 3-4 times out of the 20 times I fixed t