Originally Posted by hen555

My Jag has been giving me vibration issues and sluggish performance during normal driving.

The vibration is somewhat intermittent although I notice the following:1. Vibration is felt in the steering , gas , brake, car body, more prominent when loading the engine with pressure on the gas

2. Car does not smoothly climb its RPMs, sluggishly climbs (shuddering and unsteady). - Jaguar mechanic said this is normal do not look at the gauges listen to the engine.

3. When in vibrating phase, the engine performance does not open up. Car does not pull as hard and sound is not as good / deep.

4. When shifting using paddles, the downshifts are off, the engine shifts and then corrects its self. I see the RPMs jump to the shift point then adjust and then it slows down. I feel the shift harsh like a bump. Upshifts are fine. Jag tech checked my transmission software I'm up to date.

5. When driving over certain part of the highway the vibration goes away. It is an onramp to another highway which starts with an uphill left climb turn into a downhill low angle somewhat long highway. The highway road surface is not as smooth but you can feel the engine and steering wheel vibration is gone (you just feel the light surface roughness which is normal). During this slight downhill drive if I perform a downshift the shifts are smooth. My guess is that since the engine does not need as much load it can shift to the right point with its computer calculated gas pressure for the shift.

6. After every car wash at the gas station the car drives smooth as butter and shifts are perfect. (Maybe because it's idle for a while in the car wash?)

7. Sometimes after idling or driving slow in rush hour traffic the car gets smooth again...sometimes.

8. This vibrating issue happened about a month or 2 after I got the engine replaced under warranty. Around the same time the fuel hing flap that swings shut was found broken and hanging almost into the fuel filler neck. Jaguar tech replaced the fuel filler neck with new design but possibly a metal piece or something fell into the fuel tank...could this be the problem?

9. Wheels had slight bends, fixed the bends, vibration improved but still there is intermittent very smooth driving.. thus I do not think its the problem or it would be vibrating all the time. Roadforced balance, changed to winter tires...still getting intermittent vibration.

10. I sometimes hear a hitting sound on the front left under the hood while driving. I don't know what it is and Jag techs could not figure it out - they said nothing to worry about. It is like a loose metal bracket is hitting the side wall under the hood . This sound occurs only under load and if I ease on the gas it goes away. Also when making a high decelerating and sharp (almost full) left turn I hear a big noise from the same area like something snapped. Noticed this a few times recently.

11. I have not changed the fuel filter since I got the car couple years ago as a CPO 2012 XF. Could it be that? Only maintenance I have done are oil / air intake filter and rotar/pad brakes.

I am asking for your help because I have been to 2 jaguar dealerships now and they both are saying that the car drives normally. I am thinking of going to a 3rd dealership but it has bad reviews. I am still under CPO warranty until end of this year. I am at 120K km / 75K miles .

Please help if you can, I really like my jag.