Ford Falcon Engine Problems

I would agree with the mechanic, it’s struggling under load by being too lean. I could be a broken or cracked vacuum fitting on the engine, or even the brake booster, and I would also check the PCV valve.

Thanks for the feedback, it sounds like a very dangerous situation and one that can be very difficult to diagnose.

From your description it appears it only happens when the brakes are applied so I'd be looking for a vacuum leak associated with the brakes, such as a split or cracked hose or fitting on the brake booster or manifold.

A random spark in the inlet manifold usually causes backfiring and the most common cause of that is a faulty spark plug lead. The mechanic would struggle to find it if it only happens occasionally, and when he’s not around. I would fit new spark leads, and make sure they are a good quality, even though you say you have fitted new ones.

It's likely to be a faulty engine sensor that's not telling the computer that it's a cold start and the engine needs extra fuelling to start and run. Take it to a mechanic that has diagnostic equipment and is able to test the computer and its sensors, and if need be, leave the car with them overnight so they can do a cold start the next morning.

Is there water in the engine oil when you remove the dipstick? If there is you could have a blown head gasket. If you did, however, I would expect the engine to be running poorly. Another check you could do is to remove the spark plugs and check for signs of water on them. A blown head gasket would cost around $700-$1000 to fix depending on the condition of the cylinder head. If you’re concerned about oil in the water, that is, in the radiator it could be that you have a problem with the auto transmission cooler. The coolers are a known problem with Falcons, and when they fail water gets into the auto transmission and eventually causes that to fail.

It's clearly running hot and could be a sticking thermostat. These Falcons are renowned for having problems with the auto transmission oil cooler, which is located in the radiator. When it goes coolant gets the auto transmission and can affect the transmission if not caught in time, so have that checked.

It won’t damage your car, but it might cause it run poorly. Fuel today goes off within a week or two, so it’s not a good idea to leave it in the tank for too long.

No, he’s not. You wouldn’t change the coils unless they were breaking down and causing the engine to misfire. You can change them at any time, not just when you change plugs.

No we haven't heard of this issue before, but it clearly sounds dangerous and the treatment you have received at both dealer and company level appears appalling. I would recommend you take command of the situation and demand that it be fixed. Leave the car with the dealer until they take whatever action is required to fix the problem. It is not acceptable for the dealer, or Ford, to say they can't fix it. If, indeed, they can't fix it they should take it back and give you a new car. You could also test the new national consumer laws on the basis that the product Ford has sold you is unfit for purpose.