When in the mountains our van heats up, and our mechanic doesn’t know what to suggest. What would you suggest?
How many miles are there on the van? How often has the coolant been checked/replaced? When was the last time? I assume that the engine is overheating, correct? Describe the problem more fully.
Does the “van heat up”?
Or, does the van’s engine heat up, with no impact on the temperature of the interior of the van?
Can you clarify this for us?
As you can tell since you’ve only gotten questions so far, no one can even begin to say anything unless you provide more info.
If the van is actually overheating - making it to the red zone on the gauge - then you obviously have a cooling system problem. The list of potential issues is really long.
So be very specific about “heat up,” tell folks your maintenance history especially re: the cooling system, and tell folks what your mechanic has actually done. At the very least you could tell people whether the coolant levels have been checked.