Hi - I have a 2003 Heritage edition with the 5.4L engine. I've been reading on the forums about spark plugs blowing out and most comments say that the heads were upgraded in late 03. When were these upgrades done? I bought my truck in Sept 03 but need to check if it has the newer heads or not.

I bought my truck new and it only has about 51K on it. I've gone back to the original Motorcraft plugs (trying to get better mileage) so the plugs have been changed twice. I used anti-sieze and followed the 13lb torque spec. The Autolite plugs I had in for about a year were all tight when I changed the plugs about a month ago.

Thanks
D

 

proper torque goes a long ways, 13 ft lbs is not the proper torque...



if you have a blow out, you either need to find a new mechaninc or learn to torque

 

pretty sure the new recommended torque is 28ft/lbs...& dry, without anti-sieze

 

Pull the plugs, clean off all the antiseize you can, and retorque to 28 ft/lb.

www.blownoutsparkplug.com

FAQ's #51 and #52.

 

Hi - thanks for the advise on the plugs / torque. I've read a lot of threads on this subject and I don't want this thread to get into it all over again.

My main question is when in 03 did the heads get upgraded and how do I tell if my truck has the upgraded heads???