[Bob's944]

You said you had the belts done, how about the water pump? If it is the waterpump, you may see some steam coming from around the distributor cap. The engine would most likely overheat soon. There is a chance that the waterpump may seize, it can mess up your new timing belt and those precious valves too. Waterpumps can be had for 100 bucks, labor is usually 6-8 hrs but i've heard higher... 6 hrs is plenty for a pro shop to charge.