Hi Guys,

I have a 2006 XK8 with 114k miles. 2 weeks ago I jumped on the gas while making a left turn, about 1/2 way through the turn the engine started hesitating/missing/stuttering for may 2 seconds, when this happened everything on the dash flashed and then everything went off and then the DSC was blinking. The stuttering was just for maybe 2 seconds after those two second (I still had my foot in it) car went back to accelerating hard and 2 seconds after that the dash was normal. I drove maybe 1/2 a mile at 50mph no problem till I got to a freeway on ramp. I stopped, I put my foot in it and the car was normal. Drove the car 20 miles on the freeway at 75+ and car was flawless.

Earlier this week while driving home from work, while pushing the pedal - not WOT the car missed again and the DSC light flashed a couple of times. There was absolutely no loss of traction, and the tires did not break loose. After the couple of seconds of stuttering car drove home fine.


Today I got the car washed. As soon as I drove the car out of the car wash parking lot something didn't feel right. Car was running but not running 'perfectly'. No warning lights but just didn't feel right. I stomped on it several times, no warning lights, it revved all the way to the shift points, but it didn't feel correct.

I came home and plugged in my OBD reader. I had codes for 5 or 6 different cylinder misfires. No other codes. I cleared the codes. I shut the car off for a minute. Then started the car and drove it around the block and then checked the codes. No error codes.

I started the car heading to dinner and the idle didn't sound smooth. I drove to dinner- 20 miles of freeways. Driving the car was smooth, but it didn't feel like it had all it's power. Accelerating to pass cars it felt like I was pushing the gas down alot farther than normal to get the car to pass. And this is pushing the gas smoothly just a little not flooring it to get around a car.

Then on the way home tonight I was at a stop, and I pushed the car hard from a stop, not WOT, and not hard enough for it to shift down to 1st. The car went about 50 feet, and then stuttered, the DSC light flashed a few times, and then the car took off. Car was rolling when the stutter happened. Definitely no loss of traction.

I got home, plugged in the code reader and no codes.

Thoughts on where I should start looking .....

Thank you

Dave B

 

Check the plastic pleats in the accordion-shaped portion of the air duct running between the air filter housing and the throttle body. They tend to get brittle and crack open, allowing engine bay air in and upsetting the air flow feed, which can subsequently cause misfires and quirky engine operation. The best way to do this is to loosen the clamps, remove the air duct, and spread the pleats with your fingers while looking closely at the entire pleated area - top, sides, and bottom....

Most owners find the cracks more frequently on the underside of the air duct as opposed to the topside. That's where I found my wife's 2006 XK8's air duct had cracked back in September 2012. Some folks choose to tape the pleats up with electrical tape instead of replacing the part. If you do that, be sure to clean the area thoroughly before wrapping the entire pleated area with plenty of tape. I opted to spring for a new air duct. Cost me about $125 at the time. No similar issues since....

 

+1 on recommendation.

I'd also like to add a check of the engine mounts. Especially the one under the intake tube. If it's broken, it'll allow the engine to tilt up on that side and furthermore stress that air tube.

 

Drive it with your OBDII code reader attached and see if you capture a code when it is acting up.

 

Jon89,

Thanks for the tip. I replaced that intake about 5 years ago. I was getting a warning light on the dash, and the code reader had a code that directed me to the intake. I went out tonight and checked top and bottom and it's clean and intact. Plastic looks good doesn't looked aged or cracked.



Gus, when it acts up its only for like a second or 2, wouldn't those codes be stored in the car?


Also a little history on the car. I have had the car since 08, and the past 75K miles. Mechanically the car has been wonderful. The tranny was replaced at 52k miles with a brand new one (rock went through the pan).

The oil is replaced regularly with synthetic and has always been clean when it was replaced.

The repairs/maintenance on the driveline for the last 8 years has been:
Intake Pipe
Alternator
Radiator pipes
Thermostat Housing (2x)
Octopus cooling pipe (driver side 2x, passenger 1x)
Fuel rail pressure regulator

I have asked my mechanic every time I bring it in should I replace plugs, or coil packs, or any other preventative maintenance.... - I would rather do it before it fails. But my mechanic says, don't worry it runs great.

Any other ideas as to where to start looking?

Thank you

Dave B

 

A dirty or damaged MAFS could cause the stuttering and the engine not feeling right but not the DSC light.

 

Most codes need 2 drives from cold so expect to see them again.

 

Hi Guys....I may have the answer to the DSC fault message...Mine did this and I checked online to see what it meant and for any solutions.


Advice was to undo the DSC sensors on top of the wheel hubs (one per wheel) and remove the sensors.....they get gummed up with road dirt and then send a fail signal to the computer which gives you the DSC fault on the display.


I cleaned them with nail brush and soapy water and hey presto...the fault disappeared and never returned! That was 8 months ago.


It is an easy job and I managed all 4 wheels in about an hour....and yes...they were gummed up with black gunge.


Good Luck!

 

I agree with the MAF sensor. Try ONCE to clean it and if the problem is still there, bit the bullet and buy a new one. Bet your problem goes away.

Cheers

 

At times we look too deep. Sounds like a plug misfire under heavy load to me. ( lots of fuel, not a lot of air or RPM's) I would take a look see. Replace them while at it. Most maintenance guides call for extended miles under " ideal conditions". Not really sure what that is. Good luck. I think sometimes these little hiccups are why we drive Jaguar. Rich

 

Any updates?

 

Seeing that you have 114k miles, if I remember correctly, the plugs are usually due around 90k, but I can check for you tomorrow to verify. I agree with the previous posts regarding the MAF sensor. I cant even begin to tell you how many times I've come across this sensor causing problems with no DTCs logged. You said this started when you left the car wash, did they pressure wash the engine bay for some reason? If they did, could,have caused water to ingress somewhere. If not, keep checking for codes, and keep us posted.