Your success with solving the high idle complaint will come easier with a good plan of attack. The first thing to determine is whether the high idle is caused by a mechanical issue, such as a faulty IAC, or a throttle plate that is not closing, or if the idle speed is actually being commanded high by the computer. One of the easiest ways to do that is to simply unplug the IAC with the truck at idle, and allow the engine to slow to the "minimum air rate" or base idle speed. There is no published spec, but if your minimum idle speed is in the 500-600rpm range in park, thats close enough. There is no normal service adjustments required, but if something is keeping the throttle plate from closing, then you'll have to correct that. Most likely, when you unplug the IAC, you will find either a normal minimum idle, or no change at all. If there is no change, and the throttle is not sticking open, suspect air is getting around the throttle plate, which could be a bad IAC, because thats exactly what it does, it allows air to enter the engine around the throttle plate. Normally the computer has complete control of the IAC, but it can fail mechanically, so it must be checked. The last senario has the idle speed being correct when the IAC is unplugged, and then going back up when it's plugged back in. this would suggest the computer is actually commanding the idle speed high. The questions from here are, is the computer getting a high power steering pressure input? Is the TPS spiking low, causing the computer to think the engine is at part throttle? Is the ECT, or IAT reporting to low of an engine temperature? This is where the correct scan tool becomes so important, because it allows the person trying to fix the car to see this information right from the computer.

The only information that I've got is for the 1992, 2.3 L engine in the Ford Topaz. (It's probably the same basic layout as for the pickup truck.) So, with this warning, here's the information for the car engine. There should be two timing marks: one on the crank grear and one on the cam gear. These are punch or drill point marks. Both gears are keyed to their shafts. There is an inside and outside face for the gears. The timing marks face to the outside. The chain will have to be placed on the gears before sliding the gears onto the shafts. This may not be easy since one or both of these gears may be press fits. If you encounter a press fit, just take it easy and press each part a little at time while keeping the chain aligned. The object is to avoid damage to the chain. The keyway on the cam shaft points toward the crank. The key on the crank points straight up (and not toward the cam shaft). After the chain and sprockets are in place, the timing marks (on the sprockets) should point toward each other and be in-line with the center-line of the cam shaft and crank. (The crank key will not be on this line.) Slowly rotate the engine by hand to check for interference with a valve. If all seems ok, then check the rotor position in the distributor. It should be ok since it was not removed, but here's the check anyway. With piston no.1 at top-dead-center (TDC) and on the compression stroke (both intake and exahust valves closed), the rotor in the distriburor should point toward the electrode (in the cap) for No. 1 sparkplug. Hopefully, none of the pistons hit a valve when the chain broke. While the timing chain cover is off, it might be a good idea to flush out the oil pan to remove any debris therein, like broken chain parts. Tiny pieces probably won't cause a problem so long as these are too large to pass by the oil pump intake screen. However, larger pieces may get bounced about and caught between close passing moving parts. You can use used engine oil as a flush fluid, or a mild cleaner such as kerosene.

Dnt1, thanks! Also, to clear up - the sound is more like a blast sound from a train not the swoosh sound of one going by if that makes sense. And, I've noticed it does it when I'm low on gasoline. Could you explain in layman's terms basically what the rear end carrier bearings are?

This time last year this happenend to me, wd-40 did not work! After $300 and a lot of time on-line, I got a refund check for $215 from Ford. This is a common problem! A couple of other things to watch for is the rear wheel bearings it is also common for them to wear out, The wheel bearing are covered under 100,000 mile warranty, however, according to Ford the wheel bearing cannot be purchased alone, it comes in a hub assembly which is not covered! Tricky! They ended replacing both rear wheel bearings for the deductible of my warranty $100 vs $250 each! The other is the head. Took the car in for scheduled oil change and found the head was warped. They fixed it, the next week after finding oil under the car, they replace our engine. Good Luck!