could it be a head gasket

[95dodge]

My buddy has a 96 ford f150 with the 5.8 he as replaced the water pump, coolent temp senser, thermastat, and it is still going a little over normal that else could be the problem?

It is also jumps when ideling between a 1000 and 2000 rpm and is running rich it is getting about 6 miles to the gallon. He has replaced cap, roter coil, plugs, what can be going on

[richardlu]

vacume leak probally intake I would think

[Moogvo]

there are a lot of things it could be, but before I would go ripping into the heads, I would make sure that's what it is. First, what makes you think "Head gasket"? Is there water in the oil? Water out the exhaust? Oil in the radiator? just from what you posted, I wouldn't think Head Gasket. There are MANY things that could cause all of that. First, is the check engine light on? If so, what are the codes? How many miles are on the truck?, Is it lifted with big tires? That will not only kill mileage, but if you use the odometer to calculate fuel mileage on a vehicle with the wrong size tires, chances are that the speedometer is off, and therefore, so is the odometer, so the mileage calculation will be wrong. What about fuel? Is he filling up at stations that are using 10% ethanol? That stuff doesn't go as far as gasoline...

What about the ignition Control Module. Those are known to be a problem on various Fords. Idle Air Control Valve will cause erratic idling. Dirty throttle plates, nasty injectors and a stuck EGR can be causes for a lot of that too.

As for the reading on the temp gauge... The stock temp gauge sucks on most vehicles. Is this a factory gauge? If so, hook up a good gauge to it and make sure it actually has a temp problem. Changing the temp sensor by itself can make the gauge read higher or lower. I have seen very few that were dead-on accurate. Since the Ford gauges aren't marked in degrees, but rather C Normal and H, they are even LESS accurate!

Also, you didn't give a great deal of information, so if you would post more details, we would be more able to help out!

Good luck. Let us know what you find.