Pretty low in tank by the radiator, the coolant fluid is pretty clear just had system flushed less than a year ago. Been driving the same as always, haven't added anything to her like tires and wheels since two years ago. Oil level is right where it should be couldn't get it more in the middle of the dipstick if I wanted to. glc, really 10w30 isn't the right grade cause everyone here uses it in their fords but i wondered about this cause my haynes repair manual says the wrong grade could overheat the truck but I've ran this grade for 8 years now. Thanks for your input guys, this has really bothered my all week.

 

Maybe "everbody uses it" but both your owner's manual and the oil cap plainly says "5W30" and a TSB in 2001 changed that to 5W20.

 

Thanks for the info being reading that in the haynes manual i just got, bought my truck used and no owners manual and my oil cap just says oil on it. But really thanks for the info going to change it out this weekend.

 

I had a '99 and an '02 and I'm sure they both called for heavier oil back the, printed right on the top of the oil cap. I think it was 10-20 or 10-30. The '04 is the 1st one I've had that called for 05-20.

 

maybe the caps were for something else

 

As stated, 10W30 is not the ideal oil for a modular motor. BUT, it is not the cause of the overheating problem. That's not enough of a drastic viscosity change to produce a result such as this. Keep in mind guys, he said the stock gauge was moving. That's substantial!! That needle doesn't move from a "normal" position until the water temp is like 235-240 or something crazy. Just running 10W30 is not causing that much of an overheating problem. And additionally, I believe you said you were already using this weight anyways, correct? So you didn't change viscosity, just brand/blend?? By the time the oil is up to operating temp a 30 weight is a 30 weight. The W number is irrelevant once the oil is warm.

But I will say this also...if Im wrong and switching to a 5W actually fixes the problem, then like labnerd elluded to earlier this motor is on the verge of bigger problems.

Modular motors have always called for a 5W30 (since '97 I think) and then the swith to 5W20, never anything else.

 

Your 99 said 5W30 and your 02 said 5W20.

Even the very first year of the modular (1991 4.6 in a Lincoln Town Car) called for 5W30.