199 Ford Expedition - Cold Weather Knocking

Did your mechanic just get a new girlfriend, or boat perhaps?

Your vehicle should start as long as the fuel pickup is below the fluid level, especially after being at rest. If the fuel pump is working properly, you should hear it whirring when you turn the ignition to "on", not, "start". Turn everything that makes noise, like the radio, off. If it whirs for more than 5 seconds something is wrong.

Get the knock fixed when you can't stand it any longer.

Good luck.

The cold weather knock could, or could not be a serious problem. I have a 2002 Chevy Trailblazer that has had a cold weather knock since it had about 30,000 miles on it. While it was under warranty I took it in several times, and to different dealers who stated that it was just something inherent to the 4.3 engine. It now has about 122,000 on it and it has not gotten any worse. The knock will last for approx 5 minutes until it reaches a certain temperature. Like you, I also use synthetic 10w30.

As for the fuel problem, I would venture to say they installed an after market, the wrong pump, or installed something incorrectly. I have replaced many in-tank pumps, and after the first few, the owners either allow me to install an OEM pump, or they are politely told to take it elsewhere. Many of the after market pumps do not function nearly as well as the original pumps. I am only speculating here, but I believe it is because they manufacture the after market ones to be used in a broader number of models, making them lack something that was purposely built -in for a specific model.

The knock in the 4.6 engine is typical. I have had a 4.6 that used synthetic oil that I changed every 25,000 miles. The engine would knock for about 15 to 20 seconds after starting from day one. It has something to do with getting oil to the top half of the engine. Per Ford it is normal and is not a problem. That 4.6 when over 200,000 miles with that start up knock before I sold it. The 4.6 is a great engine. As for the fuel issue sounds like the mechanic used an after market pump which is designed to fit several different vehicles. You can't go wrong using an OEM pump. You might have to bite the bullit and replace the pump. Changing the fuel pump yourself is not hard it just requires time. If you have some basic mechnical skills and about 3 -4 hours you can do it yourself and then you know for sure it was done right!

If you were to use Schaeffer oil, the knock would most-likely go away for good!

Thanks, I fell better now.

jchip

This engine, along with all Ford overhead cam engines, are real pickey about the oil that is used in them. The piston to cylinder bore has a .0001" to =.001" tolerance. What you are hearing on start up is piston slap. The oil used in these engines should be a 5W20 oil that meeds the Ford spefications for these engines. Any other oils used will cause a short engine life, since the pistons are not properly lubricated on engine start up.

The fuel pump issue with the 1/4 tank of gas problem.

1. either he damaged the float on the sending unit on the install, but the gallons

that you have been tracking means more likely the he put an aftermarket fuel pump

in and the is fine but it is a mounting issue of the pump. if he took a short cut or

installed the new one acording to the old one you will get the problems you are

haveing. the pump needs a extention of fuel line on the fuel pump, which is no big

deal if you have it out. bottom line the fuel pump needs to be lowered. sorry but

somebody screwed up on the install. I have run across this 3 times this week on the

same style and year as yours. hope this helps

Mike