When the outside temp reaches over 85 degrees my 1994 Cougar cranks but won?t start. Once the temp drops off the car starts right up and runs great with one exception. When it does finally start up a knocking can be heard in the engine bay, this knock goes away in about 4-5 minutes of the car running. I?ve also noticed some coolant leaking from near the coolant temp sensor and from the water pump gasket. Both leaks are very small but noticeable. Please help! Thank you in advance!
I suggest you have your mechanic check the output of the coolant temp sender. If the sensor is sending a false signal to the computer the engine might not start.
A new coolant temp sender won’t cost much, and it just might solve the starting problem.
The leaks are a separate issue. If the coolant level is too low for the sender to read the temperature, problems might arise. Fix the leaks and make sure the coolant level is correct.
Check to see if the plugs are getting spark when the trouble happens. There could be a break down in the ignition system. If there isn’t any spark to the plugs then finding the fault in the ignition system should be fairly easy to do.