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Q: 1999 Jeep Wrangler overheating at highway speeds

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What could cause Overheating at highway speeds. Already replaced radiator, thermostat, water pump and hoses

My car has 97000 miles.
My car has an automatic transmission.

A: Hello. If this only occurs at highway speed...

Hello. If this only occurs at highway speeds, then you may have pressure build up in the cooling system. This is typically caused by a leaking head gasket. If there is a slight leak, then combustion pressure will build up in the cooling system and cause this to occur. A block test would need to be done to verify this. If you want to have this looked at before throwing on any more parts, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the overheating issue and verify what needs repair.

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