Liberty radio interference coming from engine

[texasjeepguy]

Hello. Well, I have a 2002 Jeep Liberty with a 3.7 engine. About a month ago, I started hearing a ticking sound coming through speakers in my Jeep. This ticking sound can only be heard when the radio is in FM mode ONLY. It is an aftermarket radio (pioneer), but this radio worked perfectly for 5 months before this problem came up. I went ahead and installed to original radio, and it also has the ticking sound in FM mode ONLY. Well, I tried a noise filter, rewireing the harness adapter in the aftermarket radio, a new antenna, and I was unable to correct the problem. Well, I read an article that directed me to use a battery operated radio to check and see if the problem is being broadcast, and entering through the antenna. Sure enough, the ticking sound is broadcast 15-20 feet away via the FM mode. This sound is only heard when the engine is on, so I know it has to do with an engine component. You guys have any idea what component it could be. I already replaced the spark plugs, so it should not be the actual spark plugs. Any help would be greatly appreciated.

 

[Sparky-Watts]

It is most likely a worn spark plug wire. It sounds like it is arcing over to the block or some other part of the engine. When you get a hole worn in the plug wire like that, the open discharge of electrical spark will cause the ticking you are hearing.

 

[texasjeepguy]

That is what I was thinking, but the Liberty comes with the coil directly over the spark plugs. Would you happen to know how I could check the coil packs? I looked for some kind of spark at night that would be doing what you described, but I was unable to find the source. I appreciate your help. TJG

 

[Sparky-Watts]

That is what I was thinking, but the Liberty comes with the coil directly over the spark plugs. Would you happen to know how I could check the coil packs? I looked for some kind of spark at night that would be doing what you described, but I was unable to find the source. I appreciate your help. TJG

Unfortunately, I know practically nothing about coil packs. I know some about distributor capped engines, but that's not much. Considering your Libby is 5 years old, it wouldn't hurt to start with plug wires anyway. I usually change mine about once every year or two.

 

[texasjeepguy]

Well, since the coils are directly on the spark plugs, my Jeep does not have spark plug wires. I wonder if one of the coils has gone bad. Well, I'll just have to go to Autozone, and see if they can check the coils for me. I appreciate your help. I will post my results once I get it corrected. Thanks. -TJG

 

[Sparky-Watts]

Oh, I gotcha. Misunderstood what you were saying about the coils being directly over the plugs. Never seen that myself. In fact, the only time I've dealt with coil packs is on my work van, it's a Ford and it has the coil pack at the back of the engine with the regular plug wires going to the plugs. Sorry I couldn't help ya, but I'm sure someone here can.

 

[Saurian]

Oh, I gotcha. Misunderstood what you were saying about the coils being directly over the plugs. Never seen that myself. In fact, the only time I've dealt with coil packs is on my work van, it's a Ford and it has the coil pack at the back of the engine with the regular plug wires going to the plugs. Sorry I couldn't help ya, but I'm sure someone here can.

Yeah, it's a strange creature, have it on my XJ, the coil is one looonnnggg bar that sits over all the spark plugs, the connection to said plugs are these little springs inside rubber boots, those look just like the ends of normal spark plug wires. Heck, the first time I saw a coil pack with wires, I was confused, having worked on vehicles with distributors, cap, rotor, that I understood, the mysterious box with the wires was a total WTF... It was driving me nuts because I went to change the wires and plugs and all on my Jeep, and they weren't there, took me about an hour to figure out where they were, under that silly bar where they should be...

Now, TexasJeepGuy, and I'm just shooting from the hip here, but I believe that if one of the coils went bad, you would be misfiring pretty badly, for example, in my I-6, there are 3 coil packs on the rail, if one failed, two plugs would no longer be firing, and the entire thing would have to be replaced... How long ago were the plugs done? It's possible that one of the rubber boots on the coil bar has been twisted or torn, causing the arc... I'd pull them, and check for debris stuck in them, or any signs of damage, I believe you can replace said boots... If the ticking is fairly rapid, I would definately say it's the ignition system, if it's not, I'd look elsewhere into a wire that might be shorting...

Hope this helps, that's all I've got...

 

[texasjeepguy]

Well Saurian, now that you mention it, it makes sense. Threre is no misfire with the Jeep. The plugs where changed about 3 month ago. I drive everyday in a 60 mile round trip to work, and the Jeep has worked very well. I don't have any probelms starting it, and no dummy lights have come on yet. The funny thing is that this radio noise is actually being tranmitted from my vehicle. I used a portable battery operated radio, and it gets the interference about 15 feet away. I have checked as much wiring as I can, but I have not found a defective wire as of yet. Everything is nice and clean under the hood, so I am at a dead end. I will get the boots off later this week so I can inspect the boots/o-rings located in each coil pack. That could very well be my problem. Thanks for your input. I will let you guys know if I can find the problem. -al