94 4.0 Bad valve clatter

[sink]

My 94 XLT with the 4.0 started bad valve clatter under any kind of moderate loading about 10000 miles ago. I gave up and took it to the dealership. All my sensors checked OK including the crank position which I might have suspected. Therefore, my spark timing must be correct. We are guessing it is carbon buildup. Does anyone have experience with this occurance on these engines. I tried a few bottles of carbon remover. No big changes yet. If this were my 350 SB in my 1980, I'd have fixed it in my sleep.

 

[Pluto]

I think I have the same type of problem.

If I set my cruise at 65mph I gst real bad clatter. If I slow down to 60 or 61 it almost completely goes away.

Really it clatter anytime I'm at 1900 to 2000 rpms. I ran a tank of premium 93 octane and a bottle of cleaner through my also. It never made a peep of noise the whole tank. So I figured problem solved.

But the clatter came back before I got through a whole tank of 87 octane.

I use my Exp. to commute 60 miles a day to work and back and with the gas prices right now, it'll end up clattering all the time berfore I start using premium in every tankfull.

 

[JYoung]

I had the same problem with pinging in the motor. I cleaned the mass air flow sensor.The problem went away.I'm not sure if this is the same because you said it was valves.But I hope this helps.

 

[Anime]

well

Well if it is carbon buildup, just keep pumpin in the cleaner and using good (detergent) gas..otherwise you can try poppin some marvel mystery oil or ATF in the tank..or just take the engine apart to clean it.


Sometimes it takes awhile to clean injectors/cylinders/etc...its not as easy as one or two bottles. I always advise the Redline stuff to start with, or just pick up a few bottles of the STP Fuel Injector cleaner (black bottle)on sale ..I'm not sure how well the STP "Fuel system cleaner" works..if its really any different. Just keep using it..and name brand gasoline.
You may have already used a few bottles of carbon remover..it might just need a few more..(if thats the problem)

Dont be tempted by cheap gas prices..stick with major petro companies..the better gas burns cleaner and helps clean your system...poor gas can cause buildup, cruddy performance, and noise.

 

[AgExplorer]

Fuel system cleaners may not be able to clean all of the carbon buildup, especially on the air intake side. Try AMSOIL's Power Foam. It will clean all the carbon and other deposits. We call it "tune-up in a can". It's worked very well for me and my vehicles.

 

[SteveVB]

Since the octane "cured" the rattle it sounds like carbon build up. One thing to check is the intake maniflod.

Do a search on lower intake manifold. Very common problem is a leaking lower gasket. Check some of the plugs. This could cause a carbon buildup in the intake, and around the injectors. Replacement and cleaning of the injectors, lower intake should help.

Hope that helps.

 

[sink]

OK- help me out. Where is the Mass Airflow Sensor and how to clean it like JYoung is talking about. I'm almost embarrassed to ask, I've changed cam and lots else on my other older V8 truck and been deep into my 89 Ranger before I unloaded it, but the Explorer's still almost a virgin to my wrench. A local shop had the Explorer recently and supposedly checked all the sensor side out, but I'd like to examine this MAS for myself.

 

[Bill MacLeod]

If cleaning the MAS doesn't help with the ping, pull
#5 spark plug and check for deposits.The lower intake
manifold bolts loosen over time on the older models,
allowing coolant to be sucked into the cylinder causing
a lean condition.Fix is to remove the upper intake and
re-torque the lower manifold.
Should allow a saturday afternoon and a few beers.

 

[sink]

OK- I think some thanks are in order to you all! I cleaned the MAS and I'm 90% sure my longstanding predetonation problem is FIXED. A few more tanks of gas and miles will confirm it. The MAS filaments looked gray and "fuzzy". I cleaned them back to shiny with carb&choke spray and a soft paintbrush. I put it back (I also slotted the screwheads so I can get them out easier without the special tool). Before I did this, I roadtripped to special eds to pick up a radio (thanks ed). It was pinging/clattering as ususal on hills. After cleaning, I ran 6 or 7 holeshot moves on the steepest hill in the township. Not one tap.
I'll let you all know the final conclusion in a few weeks. If its solved, like I think it is, I think I'm going to flame a couple of Ford service managers!
Pluto- Clean your MAS.