Still running rough ?
Asked by Ryan Apr 17, 2023 at 06:02 PM about the 2001 Mercury Grand Marquis LS
Question type: Maintenance & Repair
Hello everyone this car is a pain in my ass. SOHC. It started
with vanilla milkshake in the oil . Replaced head gaskets ,
intake manifold , went ahead with new coil packs and plugs
, and still have vanilla milkshake , running rough and now I
smell oil burning . Does anyone know what it could be?
7 Answers
beatupchevy answered about a year ago
One mechanic said once all that crap gets circulated through the engine you should do a total rebuild ,I'd say you're over your head , What have we learned ?
Your next step should probably be a car dealer. Replace this Mercury; its time is over and its done.
The original problem was probably the intake manifold. They're plastic and are prone to cracking and leaking. That would explain both the milkshake and rough running. Also, when refilling the cooling system after a flush or repair you must remove the upper radiator hose from the engine and the thermostat. You pour the coolant into the thermostat housing until it's full. Then put the thermostat housing and upper radiator hose back on. Top off the coolant recovery tank. Start the engine and as the engine warms up, top off as needed. A plugged up PCV (Positive Crankcase Ventilation) system can also give you a milkshake and rough running. Lastly, these engines also like to strip spark plug threads and blow out spark plugs from threads that are stripped when replacing the spark plugs. Usually it's the number seven cylinder for some reason. Hope that helps! Jim
Thank you Jim. You are one of the only ones that provided a possible solution rather than a unneeded lecture which does not help at all.
I failed to mention that the intake manifold has been replaced also. And I couldn't visually see any cracks in the heads. I kept the exhaust manifold and cams on while removing .
