Pinging

[94ExplorerSS]

Hey i have a 94 explorer and the engine has started to do sort of a ping/clicking sound under hard acceleration. My dad said it could need a valve job. It does have 120,000 miles on it. WHat do you think it is?
nick

 

[MrShorty]

Spark knock or ping is quite common on these engines. It's caused by the engine running a little lean. There are lots of potential causes, but the common ones appear to be
1) Dirty mass air flow sensor. Easy enough to clean, just be careful not to damage the sensor's filaments.
2) Leaking lower intake manifold (or other vacuum leak). The lower intake manifold bolts come loose and usually just need to be retightened, though occasionaly the gasket will need to be replaced.
If those don't fix it, then look at anything that could cause the engine to run lean.
This all assumes that the problem is spark knock, which is different from valve lifter noises. If you think it's valve noise, then you need to be concerned with things like oil pressure, level, flow.

 

[94expo]

Carbon Build up is the most comon problen on the 94. run a bottle of Slick 50® High Mileage Fuel System Formula. Mine was pinging and i changed and cleaned every sensor out. Pinging went away after adding this stuff to my fuel.

 

[Metallic2001]

mine has that same sound...i might check into that too

 

[94expo]

Since my pinging problem I ran the slick 50 through it and have stuck with Chevron 89 oct with techron ... Iv seen no return of the PINGING. I think the key is keep the inside clean. In fact i went on a road trip to Vegas last week and went up a 16 mile Hill with a change in elevation seveal thousand feet and It maintaned 70 mph from top bottom to top and I was carring a full full load of goodies and 5 people. No pinging and no power loss. This same trip was made Six months ago with a pinging probem and prior to slick 50 and I stoped half way up the hill to give the EX a rest. She was pinging anad running about 55 mph

 

[just2day]

MAF - Simple cleaning worked

Since I've had my X-Limited (May, 2003) and it had spark knock when accelerating with the temporary engine light. I read on here about using a tooth brush to clean it.

Well while putting in an alternator I took the MAF apart (drilled out the star bolt centers). Using a little spit and my flannel shirt, I VERY lightly cleaned the two wires. Lo and behold,, the thing runs great! No pings, no light, great running, and I can still keep the brush for my teeth. The most interesting $200 plus bucks I've saved so far.