I aimed mine at everything in the engine compartment, radiator hoses, heater hoses, cylinder heads, block, thermostat, etc. What you are looking for is hi temps, especially from the cooling system. If you find everything is normal, then you have a gauge problem. Everything in my engine compartment was well under 200 degrees so I went after my gauge.
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Leo Lipert
San Juan Capistrano, CA
'84 Wolfsburg Westy with leaky heads
'00 Golf