Hey Folks!

I'll try my best to explain the situation and I would be very grateful if anybody would be able to help me out. Alright so back in November of 2014 out of nowhere my car started shaking quite noticeably while I was in a drive thru. I parked the car, turned it off and turned it back on and it was still there. I decided to drive it home since it was a very short drive. In that short drive the car started smelling of gasoline and rotten eggs as well as smoking a bit. After getting the car home it eventually through a code on the dash which suggested one of the coilpacks had failed. I ordered the part and switched it out and it fixed the issue.

Now I'm having a very strange issue with the car. Just recently when I'd be accelerating it would feel as if the car was pulsating front to back. It wasn't a strong feeling but I could definitely feel it, out of the ordinary. Then today I've noticed a complete lack of power. The car is very sluggish and still does that strange pulsating feeling. There are no codes on the dash other than the ABS/Traction not working (which has been there forever).

Is it possible the bad coilpack messed up/clogged the cat converter? or could it be a bad oxygen sensor? Again the car is not throwing any codes on the dash for this problem. Any help would be much appreciated!!

It's a 2001 Jaguar XJ8 Vanden Plas with just over 200,000 KMS. I've put well over $10,000 into the car from two transmissions, a wheel hub, thermostat etc.

 

Pumping raw gas into the cat can cause a meltdown of the media, it happened to me with a GMC years ago. Your symptom sounds a lot like what I experienced.

 

There is a very good YouTube video on checking catalytic converters using an Infrared Gun Digital Thermometer ($40). This is far easier than disassembly to look inside the cat. If one cat is much cooler than the other side it is a good indication that the cooler one is toast

 

It could be a clogged cat converter. A bad coil should throw a code. An UltraGauge that you could monitor while running would help. I keep mine in the ashtray hooked up most of the time. You can monitor fuel trims and engine temp and other stuff as well as codes and pending codes. I believe they are about $60 now.

 

Thank you for all the suggestions. I have an infrared thermometer gun so I will try that later on.

Also I was looking under the car and noticed that a liquid (I believe it to be water) was spewing from a section of the exhaust (roughly under the driver/passenger seats). Could a leak like this cause chaos with the sensors and cause the issues with driving the vehicle?

I took a video of the the spewing and attached a screenshot below.

 

any Muffler shop should have the gauges to check for a Bad cat and aftermarket replacement at reasonable cost , Call first and make an appointment to have them checked , saves lots of time , A car that has gone fuel Rich can overheat the Cats and cause a Meltdown

 

You need your OBDII codes read, including short term and long term fuel trims. I would bet you have dirty injectors, a dirty MAF sensor, and other fuel related issues. How new are the spark plugs? Rotten eggs smell points to overly rich running (spurting, not spraying injectors, bad plugs, dirty air filter, maybe bad O2 sensors on either or both bank).

Try something simple: clean the MAF sensor, clean the throttle plate and bore (gently), run a can of fuel system cleaner through a tank of gas.

Finally, you have changed out the secondary tensioners, right?

In frigid snow country, I would never rule out bad gas or water in the fuel tank. Problem is less frequent now days with electric fuel pumps, but icing is still a potential problem.

Might try cleaning the ABS sensors on each wheel to fix the ABS/traction control problem; probably not related, but still no reason not to fix it.