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Gavin Perry
Gavin Perry,
Category: Jaguar
Satisfied Customers: 1291
Experience:  dasdasd
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I have restricted performance come up more often than

Customer Question

I have restricted performance come up more often than not...no fault codes...changed the filter...still does it...checked the filter in the tank...clear...left the fuel cap loose...no different. To me no fault codes says something mechanical...car is an s type diesel v6
JA: Has the vehicle turned into a gas hog? And how does it start -- same as usual?
Customer: no...restricted performance it uses less fuel...takes a few more turns than usual before it starts
JA: What is the model/year of your Jaguar?
Customer: 2007 s type 2.7v6 diesel
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: Taken the pump out of the fuel tank and checked the pick up pipe filter. All okay so change the main diesel filter in the front and it still doing it. It seems to do it when I put my foot down to accelerate as if it’s been starved of fuel but there are no fault codes
JA: Anything else you want the Mechanic to know before I connect you?
Customer: No I think that’s just about it thanks
Submitted: 10 days ago.
Category: Jaguar
Customer: replied 10 days ago.
Could it be something like a faulty injector?
Expert:  Gavin Perry replied 10 days ago.

Hi my name is ***** ***** it not having any fault comes we need to look for a mechanical issue as you already said. Is the lack of power there all the time.

Customer: replied 10 days ago.
No...It comes on sometimes when you turn the ignition on and sometimes it doesn’t sometimes it will drive for 25 or 30 miles then when you try and accelerate it will come on again
Expert:  Gavin Perry replied 10 days ago.

So if you re start it you get power back.

Customer: replied 10 days ago.
Sometimes it does sometimes it doesn’t...Sometimes it will come on when you turn the ignition on and sometimes it will work normally
Customer: replied 10 days ago.
I have been told that there is a pick up pipe in the main fuel pump side of the fuel tank can get blocked...
Expert:  Gavin Perry replied 10 days ago.

Then you would get low fuel pressure code from the pump. Have you checked the swirl flaps on the inlet manifold's.

Customer: replied 10 days ago.
No... At 88,000 miles the intake manifold port deactivation diaphragms were replaced by Jaguar because a restricted performance message was displayed then...This was done by the previous owner
Expert:  Gavin Perry replied 10 days ago.

ok what is it miles now.

Customer: replied 10 days ago.
if the electrical circuits to the swirl flaps were okay but they weren’t actually working would that show up on A fault code.
Expert:  Gavin Perry replied 10 days ago.

The actuator for the rod will work so the ECU will not pick up on a issue but there is more to discuss like turbo charger veriable vanes ect.

Customer: replied 10 days ago.
It started doing it after the first 150 miles after I bought the car .....for the first afternoon it was absolutely fine and then on the way home it came up with this restricted performance
Customer: replied 10 days ago.
in theory it could be that the actuator rod has come detached from the swirl vanes.
Expert:  Gavin Perry replied 10 days ago.

Yes correct.

Customer: replied 10 days ago.
Whereabouts are they on the engine?
Expert:  Gavin Perry replied 10 days ago.

On the top on the intake manifolds. Don't run away yet let's discuss turbo vanes.

Customer: replied 10 days ago.
Ok...when it runs properly I can just hear the turbos spool up
Expert:  Gavin Perry replied 10 days ago.

What is the miles it has done you never said.

Customer: replied 10 days ago.
127000
Customer: replied 10 days ago.
It should be in its prime at that mileage
Expert:  Gavin Perry replied 10 days ago.

Do the Turbos sound louder when it has the issue.

Customer: replied 10 days ago.
No, no different
Customer: replied 10 days ago.
I used to have a 55 plate S type diesel and the turbos on that were really loud but it never came up restricted performance
Expert:  Gavin Perry replied 10 days ago.

Check the swirl flaps first then if they are ok get the variable vanes in the turbo checked. What software are you using to get the codes.

Customer: replied 10 days ago.
I have a disk that goes into my laptop with an interface. And the onboard system in engineering mode
Expert:  Gavin Perry replied 10 days ago.

Just checking it is not some £15 OBD2 scanner.

Customer: replied 10 days ago.
No way...
Expert:  Gavin Perry replied 10 days ago.

ok just checking. When are you going to check the flaps out.

Customer: replied 10 days ago.
Probably tomorrow morning now ....are the actuator arms connected by those stupid little plastic ball sockets to the flaps.
Expert:  Gavin Perry replied 10 days ago.

Yes weak engernering as ever.

Customer: replied 10 days ago.
Oh joy....The kind of plastic that gets very weak after several temperature changes
Customer: replied 10 days ago.
Okay I will check the actuator arms out tomorrow any more ideas of anything else it could be? The inlet manifold diaphragms will change that 88,000 miles. how likely is it that they have failed again?
Expert:  Gavin Perry replied 10 days ago.

It is fairly easy to check them out not sure if there is a delete kit for them. Check them out then we will move forward.

Customer: replied 10 days ago.
Ok will do...I will let you know tomorrow if there is any change
Expert:  Gavin Perry replied 10 days ago.

Yes keep me posted.

Customer: replied 10 days ago.
Many thanks for your help Gavin
Expert:  Gavin Perry replied 10 days ago.

Not a problem keep me posted Tomorrow.

Customer: replied 10 days ago.
Will do