I have had some work done on my XK8 including replacement of an ignition coil and PDR of a small dent on the passenger side rear fender near where the antenna is located. I don't remember exactly when this started but now I get almost no reception on the AM side of the radio when the engine is off, and a constant whine over the speakers when the engine is running.

For a while I was also getting intermittent off and on on the FM side, signal, not power, but cleaning the antenna wire connector and antenna segments seems to have helped that.

Any suggestions for the AM side? The noise suggests a missing ground or filter capacitor somewhere.

 

I would look into the coil first; is it OEM? Improper or damaged/missing shielding on the coil would produce this type of signal interference. Also, me being me, would check all the plug wires, and anything else I could think of, that they would have touched, and make sure that the coil and spark plug wires are not crossing/tangled. I could also see the PDR causing problems, being that the vehicle's stereo components reside on a shelf inside the passenger rear fender, where the repair took place. I would check all the connectors, and grounds to the stereo stack in the trunk to make sure they are all plugged in, where they are supposed to be plugged in to. I have found that using a small handheld mirror helps to get a look at things in tight areas without having to tear into them.

 

Coil? Plug wires? Is the '99 4.0L "that" different from mine?

 

There are no plug wires as such, just a molded cap with the coil in it fitted over each plug.

Noodling around the other day with the hood up I noticed that I could almost make out the voices on the strongest AM station locally if I turned the key to position 1, power but no dash lights. On position 2, dash lit up, engine not started, the radio screamed like the gates of hell, and under the hood comes a high-pitched squeal to match it. This is presumably the oscillator for the ignition, waiting to be switched to the appropriate plug.

I had not noticed this noise before although with the hood closed, most of it is suppressed. Somewhere in there there should be either some shielding or some form of electrical isolation to keep the ignition signal off the airwaves. For fun I suppose I could find an old transistor radio and see if the car can be heard from a distance.

 

If your PDR technician did work near the antenna, that sounds like the key bit of evidence. Was the antenna ground lug connection removed? Was the antenna coaxial cable unplugged?

 

Everything looks fine back there. The ground wire was never disconnected and I pulled the antenna wire and added silicone contact lube to the connector which seemed to help the FM reception.

Next I'll pull the truck up alongside and see if the RFI is transmitting that far or if this is strictly an internal problem.

 

Did you by chance you have the fuel pump replaced recently?

 

Fuel pump is original.

So tell me, the rest of you, does your XK8 emit an audible high pitched squeal under the hood when the key is turned on?

 

No high pitched squeal here Neil.

 

It may be that your car's squeals actually translate to: " Get me the Hell out of here. I want MIAMI!!!!"

;-)

 

Reminds me of a classic Robert Klein comedy sketch concerning starting a car in the cold. Starts at 3:30:

 

Because it does not work with the engine off I would look for an antenna short first. Just about anything metal (coat hanger etc) will work for an FM antenna at VHF frequencies but AM is much more sensitive to antenna problems. With the engine off there should not be EMI, meaning you have a reception problem.

If it is not the antenna look at/change the radio mode you are operating in. I don't use AM much but i believe the jag radio on my 01 xkr can operate in USB, LSB or DSB, try all three.

 

The squeal from under the hood seems to be coming from the idle air control valve. We disconnected the 2 wires to it and the squeal stopped. The radio problem continues so I seem to have 2 problems going right now.

Has anyone tried replacing the power antenna with one of the new "shark fin" types? If it works just as well I'd be tempted to put one on each fender in the interest of symmetry. Also to annoy people with the obvious tail fin reference.

Re: That earlier picture. Everyone in Colorado knows what a Sno-Cat is. Just hardly anyone drives one around town.