2008V8 4.4Auto After driving beautifully for weeks last night it's started to judder.Engine sounds fine and strong but there is a bit of vibration Idling
​​​​​​. However when you try to accelerate either the rpm goes up to 4000 and the car goes sluggish or the back starts to vibrate.Don't know if it's an engine timing,, gear box, drive shaft or rear diff problem.
Disconnected and cleaned most electrical connectors and the air flow sensor. Any thoughts could save me hours.

 

Some ideas for you w.r.t idling:

• does it vibrate in park?
• does it vibrate in neutral?
• does it vibrate in drive but with brakes engaged?

Gearbox should not be a problem if in park or neutral…. I think.

You should be able to visually inspect the front and rear drive shafts. I think the front tends to be relatively trouble free. Rear shaft central bearing tends to go bad. The bearing is in the middle of a rubber thing which dries up and breaks eventually. Then the shaft bearing touches the metal and can convey vibration elsewhere. The driveshaft should not spin, however, if the transmission is in park or neutral.

Is there a possibility to read the codes or read live values?

 

Sounds like a vacuum leak. Oil dip stick tube seated? Oil fill cap seated? Intake plastics all tight and clamped down?

 

The car was driving brilliantly for weeks doing an average of 1000 Km a week then started to act up on my way home. That's why i felt it must be electrical or air leak rather than mechanical as surely the transmission doesn't go with no advance notice.......or does it.

Kajtzu
It vibrates and tries to pull forward when in D with foot on the brake.
Putting the pedal down at say 40 kph i get 4000 rpm and really sluggish acceleration to 100 kph

Dakota
I removed the air filter box and connectors, cleaned the sensor, opened the throttle housing and gave that a clean.
But will check the rest of the system to see if there is any vacuum leaks.

I don't have a gap tool but did get it on one the normal diagnostics tools that showed:
codes 171 and 174 System too lean on both banks as intermittent.
All fluids have been changed in the last few weeks except the transmission.

 

Lets test the PCV valve. At the intake there is that one black vacuum hose that connects just before the throttle body, disconnect and block the end on the intake tube. The on the PCV valve itself is another tube, looks corrugated. Disconnect and plug the hose that goes to the intake plenum. The PCV valve itself can be open to atmosphere since that vacuum system is now isolated from the intake.

How did you clean the MAF sensor?

Lean also implies a vacuum leak. Any other codes?

 

Hi Dakota.Took the car to a land rover mechanic who test drove it. His opinion is fuel pump and spark plugs. After that the cat may be blocked but he was convinced the pump was almost gone and the plugs dying. There has been a noise from the rear that I thought was road noise but could be the pump.
There was no difference disconnecting the maf cable.

 

Turns out it was the plugs and two coils, however as its a land rover the rear wheel bearings need replaced as they were making a noise..

 

Well better than a fuel pump. Odd you would have plug/coil issues that present as lean, usually bad plugs and coils that are failing present as rich because fuel is not being burned properly. And that is unfortunate about the rear wheel bearings. I did mine at 172,000 miles (276,800km) just out of caution and they were fine. They typically last a long, long time unlike the fronts. Your bearing went pretty early on. They are not a n easy install like the fronts, they have to be pressed into the knuckle and there is a lot of work involved.