i have a 98 5.4L f150 with 345,000miles on it and recently the radiator sprung a leak. i have order a modine radiator to replace it and have been driving it while keeping an eye on my coolant level. anyway a week into driving it with the leak the truck now shakes. the weird thing is it doesnt do it until i hit 30mph then it shakes like a bastard, i have never seen or heard of anything like this. the engine still has full power, or at least seems to and has a proper coolant level, anyone have any ideas as to what it could be?

 

Sounds like a misfire - you have to be more descriptive. Keep pushing it , you'll get a light. Sometimes you have to push a misfire before you computer will realize it . The comp will try to compensate , when it can't , you'll receive a light - you need to push it to get it there.

 

345k????? Wow. I'm impressed. Get the truck up to driving speed, and in a safe place, free of traffic, shut it right off. If it stops shaking the engine is misfiring. If it still shakes, there is a driveline or suspension problem.

 

Or there soon will be shuting it off like that lol

trans is electric - the pump don't work without power

 

thanks for the input guys, changed the radiator and turns out that as pressure built coolant was hitting the fan and most of it was landing in the area of one of the spark plugs and it got saturated and.. well the rest is common sense

 

wow!!! 345k if my tranny and motor last past 200k ill be happy i got my moneys worth.