Hi Everyone,

I have a strange issue that I have noticed on my 03 XKR. When I make a left u-turn the engine temporarily cuts out at the apex of the turn. As soon as I am straightening the car out the accelerator pedal works again and all is well. This only happens on sharp left u-turns.

Do you guys have any idea what cause this or has anyone had the same issue before? It is very strange as the engine purrs otherwise.

Thanks!

Corey

 

Bad motor mount?

 

Very unusual problem. My neighbour had same symptom but on a different make car and he discovered that his Engine Earth strap was damaged. On sharp turns he lost power to ignition circuit which stopped the engine.

Just a thought, but it may be worth you have a quick check of yours. I found this video showing engine earth strap location on X100 and how to add a secondary earth strap on the other side....
.

 

Sorry on my delayed reply! I worked on the Jag this weekend changing out the plugs and coils. On a side note, new plugs and coils on my 108k mile XKR seemed to make a real difference in throttle response.

Anyways, I am not sure if this is how you would check the motor mounts but I tried to rock the engine and move it around. It seemed very stable to me, no play whatsoever.

 

Thank you for this suggestion. I will get under the car later today to see what they look like. Perhaps it is losing connection with the momentum of an abrupt turn and cutting out the power to the ignition system. I also replaced plugs and coils for good measure since I have 108k on the car and one of the coils went out last week. 6 of the 8 looked original so I think it was really good preventative and easy maintenance and I noticed she is running smoother with better throttle response. I wonder if the coils had anything to do with it cutting out. Going to try a sharp left u-turn after work today and see what happens.

 

I'd say take a hard look at the intake pipe. Maybe a crack opens during turns, leading to a lot of unmetered air. The scenario would be a bad mount allowing the engine to rock, which would pull the intake accordion apart and create a massive but temporary air leak.

Best of luck, keep us posted.

 

A simple test of motor mounts is to have someone rev the engine in gear (brake on) while you watch. There should be very little motion.

 

Corey,
1. Motor mounts - open hood. Engine on. Stand on brake (IOW high brake pressure to ensure no movement). Put in drive. Rev engine, if mounts are bad you'll see the engine movement. It'll be obvious.
2. Cut out. Does this happen with Trac Off button activated? (Button red light on) in cars with Track Off not activated, wheel slippage, or something telling the car there's serious loss of traction, will cut engine power to the point it feels like engine died. Drove me nuts for a while when I first got the car. Then with this forums help I learned she was working as designed! I quickly learned to push the Trac Off button before making hard left turns = 100% power.

John

 

Thank you guys for the info on how to test the motor mount. I tried it this morning and she definitely moved a fair amount. If I had to guess it went up about an inch to an inch and a half on the driver's side. Add that to the list! ha. I tried the sharp u-turn and it did not cut out after three attempts. Maybe fmertz was right about the intake pipe. I had it off Sunday when replacing the coils and plugs and it is definitely on tight right now. I wonder if it was not before. Will keep everyone posted on how this develops. Thank you all for your help.

Oh and John, it definitely was not the traction system. I share your frustrations though with the undesirable loss of power at inopportune times.