Engine noises

[flyhigh5574]

I have lately been hearing noises in my engine that i'm not quite sure about. When I start the vehicle there is a knocking noise that eventually quiets down. Then at idle there is a ticking noise that ticks with the idle. And last, lately there has been times that when I accelerate, the engine almost sounds like a diesel. Any ideas on what this may be? Thanks

 

[Creager]

sounds like an explorer to me =)

try new plugs, wires

89 gas

and change your oil

 

[flyhigh5574]

Did all of this not too long ago. Everything besides 89 octane. My concern is it sounds like something may be bent or broken inside. I've also heard that sometimes certain knids of spark plugs will make these engines sound worse as well. Any ideas on this? Thanks for the quick reply.

 

[Creager]

ill tell ya what man. You have a '91, i gotta '92. We actually have the exact same pushrod 4.0.

if anything was broken, bent in the engine you would know it! it wouldnt be running very long.

Spark knock is what your talking about... does it sound like marbles are in the engine when you floor it? yeah thats denotation or whatever its spelled. I still get it when i run 87. When i run 89 it totally goes away... dont ask me why.

I actaully heard a rumor somewher that ford timed the computer on these to like 89-91 gas, but labeled the truck for 87

I havent heard any of those noises since i switched to 89. Give it a try. im pretty sure that might fix your problem.

That knocking noise, is it like when you just accelerated/when the truck is under inital load? Does it also happen when you decel and accel again on the highway? That most likley is your U-Joints. only like 10 bucks at most autoparts stores, but you will need a C-Frame press to do the job. You can get one of those from http://www.harborfreight.com/ for 20 bucks and its a very very very worth while tool

 

[flyhigh5574]

Thanks again, I will switch to 89 octane and see what happens. By the way, what kind of spark plugs do you recommend? I heard BOSCH are not good for Ford. Is this right? Thanks

 

[amessie]

Put some plugs in with a heavy tip (autolite, motorcraft etc.) Those puny platnuim bosch tips can't stand up to detonation.

 

[TPLYNCH]

You may want to seafoam the carbon out of the engine as well....

 

[ve4ron]

Clean your Mass Air flow sensor.

 

[Creager]

Yeah i forgot to mention that cleaning your MAF sensor will probably help the most. That job is pretty simple. You have to get a Tamper-Proof torx set, which is like 5 bucks at autozone.

You unscrew the torx on top of the sensor, and the sensor will come right off. Use Gum-off Choak cleaner (the kind thats OK to use on electrionics) and spray the little prongs until they look nice and shiny... then let the sensor sit in the sun for like 20 minutes to dry and... and go... easy

I use autolite, make sure you gap them right!! i forget the correct setting (need to refer to the haynes manual, but i think its .45)

 

[flyhigh5574]

Well...I switched to 90 Octane fuel, cleaned the MAF, cleaned the IAC also. Seems like a little improvement but not much. The main improvement that I noticed is it has more pickup when you get on the gas. From what I noticed, the ticking noise is gone, but it has only been one day since I did the cleaning. My only concern is the vehicle sounding like a diesel when you get on the gas. Any ideas on what to do next? I also noticed that the fan blades are cracked. Could this lead to any problems? Also, when I pulled the IAC off, there was a black greasy coating on the inside of the throttle body and also in the IAC. Is this normal? Thanks again!

 

[monkeydude3]

definitely clean that crap off of your IAC, In my experience cleaning tha thelps a lot with the idle if the IAC is still good