Mercury Repair Questions? Ask a Mechanic for Answers ASAP
Hello and welcome to JustAnswer.
My name is Vlad.
I need some more information please.
1) is it 3.8L engine?
2) When it stalls, can you restart after that? Does starter turn the engine over at least?
Please reply back
1) You mention that it "shakes" when being driven so I would inspect spark plugs and ignition wires or just replace both if it has not been done recently. Those 4.6L engines are known for ignition wires issues causing misfire.
2) For engine stalling issue, I would start from fuel system . It is quite possible your fuel pump is about to fail and does not supply enough fuel at times. Would be a good idea to have it checked for trouble codes as there are too many reasons that cause engine stalling so any stored trouble codes could help to nail it down.
3) Overheating- make sure the cooling system has been bled properly and there is no air pockets in the system. if not, it will prevent coolant from circulation resulting in overheating.
The thermostat could be another reason for that.
A faulty water pump ( corroded impeller) would also cause the situation you described.
I am just checking if my answer has helped or you need more assistance?