I've got a 95 XJ-6 which started running really poorly. While driving on the highway, the car started shaking so badly that I worried I had lost an engine mount.

I went and had the EGR recall done, but it wasn't any help. The dealer blamed the plugs after replacing the EGR valve, but I put in new plugs and it still runs poorly. I checked all the coils and they all have a good spark. All of the plugs I pulled out (only a few months old) looked good except for the third one from the front of the car, which was wet and black. Sometimes while driving the oil pressure drops to zero, though I'm not sure if that's related or just a flaky sensor.

From the way the plug looked, I suspect that cylinder isn't cycling properly. Beyond basic maintenance, my only experience working on engines is with Wankel rotary engines, so I'm not sure what to check on one of these crazy things with all the cylinders in it. :)

Can anyone point me in the right direction? Stuck valve? Bad seal?

Also, is there any aftermarket or factory guide to the 95 that's easily available?

Submitted by bwalker@boredom.org on Sat, 04/26/2003 - 17:12

This problem is worst at idle. At high rpm it's far less noticable, though it feels underpowered, so I suspect it's still there. The coils all seem to have a healthy spark, too. I tried swapping the coils between the bad cylinder and a good one and it didn't seem to make any difference. The new plug I put in the bad cylinder was still wet (looked like oil) when I pulled it out and the other one looked clean.

On the subject of coils and sparks, what do people wear when working with the coils? I've worn extremely thick gloves with rubber grips when pulling a coil out and still gotten zapped. Nothing like actually grabbing the terminal would be, but enough to be annoying. As large as the coil bodies are, I'm shocked (pun intended) that you can get zapped holding the LV end of them.

Submitted by pascal@jcna.com on Sat, 04/26/2003 - 16:23

Bill

I recently had a slight misfire only under hard acceleration on the XKR ( 75% throtle or more), finally cured under warrranty by replacing 5 of the coils... didn't set an check engine light.

Pascal Gademer
72 E-type 2+2
00 XKRCoupe
99 XJR

Submitted by bwalker@boredom.org on Sat, 04/26/2003 - 14:37

105k miles on the engine. I've owned it since 82k and it's never had a single engine problem. (Well, I just blew $2k getting the air flow meter and both O2 sensors replaced, but that's not really an engine problem.)

Is there anything special I need to do on the X300 to do a compression test? The jag-lovers X300 guide doesn't give any instructions. Do I just pull the plugs and the EFI/fuel pump (not near the car to check what parts of the injection system are fused) fuse?

Submitted by bwalker@boredom.org on Sat, 04/26/2003 - 11:12

Thanks for the quick reply.

No check engine light. I know the check engine light was working a few months ago because it came on when I had to get the o2 sensors and airflow meter replaced. I'll check it to make sure it's still working. *wanders out the front door*

Yep. All the idiot lamps are still working fine. No check engine light while running. (Seems odd if it's sensitive to misfires, since I was pulling the coils to test for spark.)

Submitted by vp@catdriver.com on Sat, 04/26/2003 - 01:38

First..

Are you getting a check engine light? They are pretty sensitive to misfires.. if you are, let me know then and there. The 95+ Sedans are ALL OBD2 so you can get this Scanned at AutoZone if you have the light. A P0303, for example, is misfire cylinder 3. This is, 98% of the time, a bad coil pack. And it's not uncommon on x300s.. I have a '96 VDP at the moment that needs a #3 coil pack. And these are intermittent when they go.

Internal engine problems on these cars are VERY VERY rare.. In being around these cars since they came out I have seen 3 engine failures. 2 were due to dramatic neglect.

first thing to do is a compression test if no check engine light is on. OTOH... Turn the ignition key on and don't start the engine, the CHECK ENGINE light is on the left bank of warning lights at the bottom. It's conceiveable someone yanked the bulb to hide a problem that's gotten worse.

Lemme know what happens here..

Bill Weismann
vpatcatdriver.com
407-765-4110 cell