My 89 f150 302 2wd automatic runs perfectly fine however when coming up to a hill and it doesn't downshift to a lower gear it will make a loud rattling flutter sound that sounds right at the firewall. I have set my timing to 14* btdc and all new motorcraft plugs properly gaped and motorcraft wires and ignition coil as well as a new fuel pressure regulator. It made the noise before all these parts and still does it. I run 87 fuel as well. I have new ujoints as well as a new exhaust system. The AIR system was just left open due to my new headers not having the provisions for the air tube. Any help would be great. The noise is loud but if I am to step on the gas some more the noise goes away so I don't thinnk its internal or spark related it did it with timing at 10* as well

 

That's detonation and it's not good for the motor so you need to eliminate it. The open air injection system is not good either, one of my trucks developed the same detonation problem when the valve at the rear of the motor broke and let fresh air into the exhaust system, so you need to either completely remove the system and plug the openings in the heads, or put it all back on and make it functional.
And then you're going to have to retard the timing until the detonation is eliminated or at least greatly minimized, these engines should run at 10deg advance no problem so if you're still getting some at that setting run seafoam through the motor and fuel system to remove carbon deposits on the pistons and to clean out dirty injectors.

 

Ok I was afraid of that. So if I plug the openings on the back and set timing to 10*btdc I should be ok? It was to my understanding I need to advance timing per my altitude.

 

Advancing the timing will compensate for some of the power lost due to thiner air at altitude, but every motor is different and each one will tell you by detonating when it is seeing too much advance and you can't go past that regardless. You say the motor behaved the same with the timing at 10deg, if so you have a problem you need to sort out so start by pulling the codes and blocking off the air system properly.

 

IIRC holes in the back of the heads are 5/8" coarse thread.

 

Ok.. I dont have any codes thrown. I have performed several KOEO and KOER tests with an 11 pass code on everything.

I have the correct bolts to plug the holes in the heads. They are 5/8 coarse thread 1" long and I have a nylon hi-temp washer for each one. I will try to get to those and the timing today or tomorrow. I only drive the truck on my time off so I wont be driving it for another 5 days anyway. If doing the timing adjustment and plugging the holes does not rid of the rattle I will be at a loss. I am no mechanic so it looks like it will need to go in a shop.

 

Check your EGR valve. There is a little green hose that connects it and it is towards the back of the engine, more on the drivers side. If the hose is cracked,you will get pinging. I replaced mine after it broke, and the pinging went away

 

just to throw this out there, dose it sound like its pinging? if your runnung 87 octaine fuel just throw in some high octaine fuel in it and see if it goes away, usually you could solve that with timing but ive ran through that ( more so with imports) that i had to run better than 87 to stop the pinging issue

 

All vacuum lines appear fine i have physically checked them all by hand and with carb cleaner. I have yet to get the bolts to plug the heads i did notice on the back of the motor theres a nother little tube with a vacuum line connected to it that is all connected by rubber hose to the AIR system. Do i just unplug the vacuum line? Once i plug the heads thqt hose will be useless

 

The Air Injection system will have 2 vacuum activated solenoids, the one behind the motor that you found and another down on the passenger side. These valves and all attached plumbing back to the air pump and down to the exhaust system should be removed once the heads are plugged, and then the vacuum lines should be plugged.

 

Perfect i found all that sounds good. My other question is, i was just out looking at the back where the air lines are in the back of the heads and they appear to be solid blocks with some tiny 1/2" bolts through them. Do i remove those bolts and use a big set of channel locks to twist off the blocks or do they pop off?

 

Take the bolts out then the blocks should come off with a little tap.

Here a photo for reference:

courtesy of Conanski

Once the cross-over tube is removed you will see the thread port in the back of the head that needs to be plugged:

 

late update but I have since removed everything and plugged it off properly and the sound has went away. Now I am just dealing with a rough idle

I get a code of 44 during KOER

It is a thermactor code but I dont know where to start so I was going to clean the EGR