[keith806]

Hello All,

Long time lurker, first time poster. My 2007 LR3 has had three instances where it accelerates on its own. While driving 70MPH it just took off, lunged while trying to park (sh#t pants) twice. Has anyone experienced this? Remedy? Family vehicle so safety is a huge concern. Thanks for any info.

 

[RoverGuy7]

The lunging while trying to park, and other low speed maneuvers can be a symptom of carbon build up at the throttle body, however that would not explain by any means the acceleration at speed.

I would clean the throttle body if there is any build up, and go from there. Personally, I would recommend a full induction service, but just for this concern, cleaning the throttle body may resolve that side of it.

There are no service bulletins related to this problem.

 

[keith806]

Thanks, I'm taking to LR Colorado Springs tomorrow. I will recommend full induction service. Appreciated.

 

[Rover_Hokie]

Any chance your cruise control made it take off at high speed?

 

[wags]

Dave I used some Mercury Quick Silver carbon cleaner for 2 stroke outboards on my DII THROTTLE BODY and it really worked because it foams up and stays on it better. I use it in gun barrels and anything with carbon build up. Any boat place will have it. Ever used it?

 

[disco biscuit]

I agree with the above statement. If its coked up you almost have to scrape the carbon off, very hard to remove. Gun cleaning solvents work. Not on anything electrical.

I have to say Super Unleaded is the ultimate cure for situations like that. Conversely, its usually a symptom that you haven't been using well detonated petroleum. Maybe a bad manufacturer. I recommend Chevron, Texaco, Shell. They are owned all owned by shell but Texas started most of those companies. Techron is they're additive/cleaner and they're additives and octane adjustments are far and away better than the competition. Google it. I would venture to say you could add a bottle of Techron, they sell it in a bottle, to a quarter tank of gas...run it a few mins and fill up at a chevron station. I bet it levels out.

Almost all carbon build up problems are poor unspent gas left in the system.

 

[RoverGuy7]

I have not used that wags, I would be careful with something foamy, as you don't want it to creep into the shaft holes and into the electrics. I use, and swear by, BG products, but I am a mechanic, and it's much easier to get then as a consumer.

As to the carbon build up, on these it is usually more so caused by oil vapor in the intake due to a pretty poorly designed PCV system. It usually doesn't take much effort to clean it up, just let it soak in a good cleaner for a few seconds and wipe it away. I will note that Jaguar and Land Rover do not recommend physical cleanings of the throttle body, as they say there is a coating that will be removed. However, I have not noticed any sort of coating, even when brand new in the box, and realistically if there is, it isn't a very good one as they carbon up pretty quick.

 

[keith806]

To address Rover Hokie, the gas pedal does depress as if the cruise control is selected to accelerate. Short in cruise control module? If there is a separate module, not sure how configured.....