after installing new head gasket car ran great. drove it about 300 miles with no

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issues. soon noticed low coolant light. no overheating though. checked oil and it was clean. drove another 80 miles and oil got dirty (but not milky). changed oil and filter and drove 10 miles and checked oil and noticed coolant innermix. (got real thin). engine will start and sounds great but shut it down right after and won't drive it till I find out what the problem is. I used a victor ruiz head gasket and had the head cleaned and checked for level. I suspect timing cover gasket but could be something else. had diagnostic done with no issues.