Jaguar 2001 S-Type 4.0 71000mi. Sluggish

LEESTANFORD

MEMBER
2001 JAGUAR XJS

Over last 5 months gas mileage went from 18.8 to 16.2 mpg. When I step on accelerator, car runs rough as if a sparkplug failure. I have to backoff the gas pedal for engine to "recover". Engine light has been on for 5-6 monthis on and sometimes registers "6" flashes or sometimes "24" flashes. What could be causing the sluggishness. And what do the "6" and "24" codes mean?

7 Replies

2CARPRO JACK

MECHANIC
11,533 POSTS

Dont know about the flashes, but it sounds like the Mass Airflow Meter

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Tuesday, April 25th, 2006 AT 4:54 PM

JUPITER

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1 POST

I have s type 1999 4.0 v8 and seems to have same problem, on a diagnostic machine it indicated it needed airflow meter one was put on but made no difference :(

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Monday, June 26th, 2006 AT 4:19 PM

FSTRANGER302

MECHANIC
117 POSTS

It does not sound like a mass air flow meter. It does sound like a weak coil or oil getting into plug wells. This will cause the rubber insulators to break down and on accleration the spark will jump through the boot to the cylinder wall causing a grounded plug

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Wednesday, September 20th, 2006 AT 9:12 PM

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You may have one or more ignition coils that are starting to go bad. Whenever an ignition coil goes bad, your vehicle will not idle smoothly but will pulsate. You will also feel a significant decrease in power and gas mileage. Your vehicle will also sputter when the accelerator is depressed. If you have any of these symptoms then you may be experiencing an ignition coil problem. The reason the coils go bad is that the spark plug seals leak oil into the spark plug wells and prematurely burn out the coils. To check it yourself (very easy to do) you will need to remove the ignition coil cover which is located on top o the valve cover. This is only about 14 X 2.5 inches and there are only six screws to remove. Once you have done that you will see four ignition coils each held in by only one screw. Once you remove the screw, detach the retaining clip (wire) and it will pull out. Once you have done this, take a flashlight and look inside each spark plug well and see it oil has entered. Hope this helps and good luck.

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Wednesday, October 11th, 2006 AT 12:10 PM

JAGTECH06

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7 POSTS

I am a Jaguar mechanic and we have a recall on your year model car. There is a breather neck below your intake manifold that tends to eat away and create a vacuum leak. This tends to make the car feel like it has a misfire and runs pretty bad. This also sets up your MIL.