Knocking

[allmightyjt]

Last week replaced 6 plugs and wires from the factory original. 46.5k miles (barber shop and back until I got the truck 4 years ago) Ran much better, sound response ect. Trying to do the last two drivers' side back plugs today. Get it all done and crank. Loud knocking immediately. pull the plug and its bent. its a bosch plat +2. Ran to the autoparts store and bought a new one. redid the last two plugs. crank, and the same thing. Then I put the old motorcraft plug back in where the plug got bent. Same knocking but a slightly different tone.


1997 2.3L Ranger

 

[black_demon69]

Last week replaced 6 plugs and wires from the factory original. 46.5k miles (barber shop and back until I got the truck 4 years ago) Ran much better, sound response ect. Trying to do the last two drivers' side back plugs today. Get it all done and crank. Loud knocking immediately. pull the plug and its bent. its a bosch plat +2. Ran to the autoparts store and bought a new one. redid the last two plugs. crank, and the same thing. Then I put the old motorcraft plug back in where the plug got bent. Same knocking but a slightly different tone.


1997 2.3L Ranger

if plug is bent it is too long and got smacked by piston make sureb that you have the right ones.. also do yourself a favor and get motorcraft or autolite plugs fords always run better on them..

autolite iridium part # xp104
autolite double platinum part # app104
autolite platinum part # ap104
autolite copper core part # 764

motorcraft platinum part # sp432

part #s pulled from this site http://www.oreillyauto.com/site/c/s...ear=1997&make=Ford&page=1&results=20&sortBy=4

 

[allmightyjt]

visually it looks slightly shorter than the original motorcraft, but just in case I did try reinstalling the old plug with no luck. I've had good luck with the bosch plat in the past with a mustang I used to have. And the first six I replaced gave no issues and it ran much better.

 

[black_demon69]

anything drop into cylinder?

 

[allmightyjt]

Not that i'm aware of. but that particular plug you're working blind

 

[bmerr98]

Yikes. I hate when something simple goes south. You could try to vacuum the cylinder out. A shop vac, some small flex hose and duct tape worked for me when I changed plugs on my '06 Expedition. All 8 plugs broke and left ceramic pieces in the cylinder. I was able to get most if not all of it out and had no problems with bad noises. Might be worth a shot.

 

[allmightyjt]

Ill keep that in mind. Any idea if a telescopic magnet or bore scope would help? if it was fine before then it shouldn't be mechanical right?

 

[drsvox]

you might try hand cranking to see if you can maybe hear what's going on and/or feel for resistance or anything when that piston reaches tdc...

try w/ plug in and w/ plug out...make yourself a "stethoscope" w/ 5/8" vacuum hose; one end in the plug, the other in your ear (may need a second pair of hands to help).

might not solve your problem straight away, but could help you diagnose.

 

[allmightyjt]

I did try it with out the plug. Very difficult to distinguish air from knock. after putting the OEM plug back in it changed the sound from a loud knock to a sewing machine-esque knock that wasn't quite as loud but still present.

 

[drsvox]

...then I would probably try sticking the magnet down there and see if you pull anything out; try vacuuming it too.

if that doesn't work or fix the problem, my next step would probably be to pull the valve cover off and start looking topside for problems; especially with the valves...not really sure what a smashed plug could do damage-wise : (

 

[allmightyjt]

I read something elsewhere about the threads, could tightening the plug and backing it out half turn or so be a viable option?

 

[bmerr98]

I read something elsewhere about the threads, could tightening the plug and backing it out half turn or so be a viable option?

The correct plug should have clearance when tightened. Backing it out would lose compression too, wouldn't it?

 

[Will]

I don't change plugs. My wife's car is 9 years old and I did the timing belt when it got to 105,000, but not the plugs. The timing belt I took out looked very sharp and new, which pissed me off. My 4.0 started to rattle and lose oil pressure back in 2001--I pulled the motor, replaced the bearings and oil pump, disassembled and cleaned the lifters, put the motor back together and put it back in. I never removed the plugs and still haven't.

Old breaker point ignitions were crap. The points allowed very little coil saturation even when set properly (which is why dual points were used--they overlapped each other and gave a little more saturation for a hotter spark) and plugs back then had narrow gaps because you had a lot less voltage--especially when they wore the friction surface that rode on the distributor cam. Plug maintenance was essential because any little bit of wear would open the gap enough that the spark wouldn't jump it. Since CDI came around, an ignition spark can jump an easy inch--with points it was tough to get 10,000 volts when there was some use on the motor. Now, I think 60,000 volts is easy. Like I said, my wife's car has probably close to 130,000 on it and I have never even thought about changing the spark plugs. Stripping the aluminum threads or dropping something down the holes is enough of a risk that I will wait for an actual problem before it is worth the risk screwing with it.

If it isn't broken, don't fix it. If it works, leave it alone. I'm always encountering people who break stuff doing 1960's preventative maintenance on a modern car which requires only oil changes--and very infrequent ones.

If I were you, I would pull the head off and stop driving it. It seems like something in there is tearing it up. It's a simple engine, it would take an hour to find out what is going on.

 

[black_demon69]

I don't change plugs. My wife's car is 9 years old and I did the timing belt when it got to 105,000, but not the plugs. The timing belt I took out looked very sharp and new, which pissed me off. My 4.0 started to rattle and lose oil pressure back in 2001--I pulled the motor, replaced the bearings and oil pump, disassembled and cleaned the lifters, put the motor back together and put it back in. I never removed the plugs and still haven't.

Old breaker point ignitions were crap. The points allowed very little coil saturation even when set properly (which is why dual points were used--they overlapped each other and gave a little more saturation for a hotter spark) and plugs back then had narrow gaps because you had a lot less voltage--especially when they wore the friction surface that rode on the distributor cam. Plug maintenance was essential because any little bit of wear would open the gap enough that the spark wouldn't jump it. Since CDI came around, an ignition spark can jump an easy inch--with points it was tough to get 10,000 volts when there was some use on the motor. Now, I think 60,000 volts is easy. Like I said, my wife's car has probably close to 130,000 on it and I have never even thought about changing the spark plugs. Stripping the aluminum threads or dropping something down the holes is enough of a risk that I will wait for an actual problem before it is worth the risk screwing with it.

If it isn't broken, don't fix it. If it works, leave it alone. I'm always encountering people who break stuff doing 1960's preventative maintenance on a modern car which requires only oil changes--and very infrequent ones.

If I were you, I would pull the head off and stop driving it. It seems like something in there is tearing it up. It's a simple engine, it would take an hour to find out what is going on.

changing plugs has to do with saving gas because as plugs wear the gaps get wider and less efficient. also at some point they will stop firing altogether. as for stripping threads on aluminum heads you should change plugs with cold engine, apply antiseize to threads, and start them by hand same applies to cast heads as well. also helps to blow out area around spark plugs just before removal to prevent any debris from falling into open cylinder.....

personally i will continue to do the preventive maintenance because i don't like being stuck on the side of the road or having to pay a tow bill...

above is just my opinion and no offense is meant

 

[allmightyjt]

Been doing some asking and some prodding. Was able to recover this with a magnet, dirty penny for size reference. Its still knocking, ill hand crank some and stick the magnet in there, then repeat. Someone suggested the piston ring might be broken. How likely is this? Also, my brother cranked it and revved it to yield white steam like exhaust. Ill likely attempt a shop vac once i can get my hands on one.