V8 P450 Power Loss Issue

[ToyCarMan]

Hi all,

Yesterday, I upgraded from from a lovely and fast MY18 V6 R-Dynamic to a dog slow V8 First Edition P450 ...

Here is the quick version.
1. First drive from the garage and everything is OK - no power issues at all.
2. Mostly used Cruise Control for a long journey back home - activated and then disabled Spd/Limiter a few times (older V6 didn't have that - so wanted a play with it).
3. After a few pit-stops on the way back home, (6hr drive) I noted that the car showed VERY limited acceleration even when my foot was planted to the floor. (No engine Warning Lights)
4. Only way I could achieve reasonable acceleration was to keep car in Cruise Control and ride the (+ / -) buttons. Even Sport and Dynamic Mode did not make a difference.

It is almost like the car is stuck in some form of speed restriction mode (but Spd/Limit was definitely not on)
I've considered previous posts about MAF sensors, ill-fitting or wet air filters etc BUT the car can go fast - but not with the accelerator pedal - only cruise control.

Things to know:
There have never been any Warning Lights.
Dynamic Mode can be engaged (i.e. dash goes RED)
I've not run a Code Reader yet (scared as my V6 never recovered from "Low Battery" issue due to the OBD port power-on issue (despite battery resets) - has this been "fixed" in newer F-Types yet?
Also - if I am going slow and press the RES button (to re-engage the last previous set Spd/Limit speed) the car jolts into action and reaches that set limit no problem.
The approved Jaguar garage is a 6.30hr trip from home

Any assistance would be great - I just purchased this yesterday so not had a full look around the new dashboard menu system yet - that's todays job!

 

[gasgas]

Think you can reset the gear box, but not sure as it drives as what it's use to?

 

[ToyCarMan]

Think you can reset the gear box, but not sure as it drives as what it's use to?

Ah... are you referring to this procedure (just don't want to get it wrong)..

1. Accessory Mode ON
2. Full Throttle for 30secs
3. Accessory Mode OFF
4 Live the Dream!

I will try this - as the issue does seem linked somewhat to pedal travel.

 

[ToyCarMan]

Hmm, so started the car today and everything seems fine. Did a combination of town and motorway driving with no loss in power at all and kept the engine running for a further 40min before repeating the process. Everything (thankfully) still fine.

Came home and did the gearbox reset (detailed above) no observable change from this morning but again no issues either.

Has anyone else experienced this?

 

[ToyCarMan]

UPDATE - the issue is BACK!!
I went on a longer motorway run today and deliberately used Cruise Control the entire journey (as much as possible any way) and kept the engine running when I reached my destination. Everything went smoothly.
However on the return journey, I used combinations of Sport Mode and Dynamic Mode using the paddles every now and again.

• About 6mins in, I received a message which I swear said: "Erratic Driving Detected, engine performance restricted". -I now remember seeing this message near the end of my first drive - but I was still getting used to the new digi-dash layout.

• After clicking "OK" there was no further EML showing anywhere on the dash at all.

• I pulled over and shut the engine off for approx. 5mins

• Scrolling through the car warning messages revealed the message shown in this post

I started the engine and drive home again, experiencing no loss in power or any further warnings - I deliberately drove in the same manner using combinations of Sport and Sport + Dynamic but could not replicate the issue. Even the Remote App showed no issues!

I can find lots of posts about loose wiring connectors and fuel pump delivery issues etc - however I cannot find anyone who has even seen the message that I believe that I observed i.e. "Erratic Driving detected - Engine Performance Restricted". The only observable (beyond power loss ) is the standard "Restricted performance" message that accompanies "Limp Mode" - attached to this post.

So can this be linked to the perceived behaviour of the early part of the drive (cruise control) suddenly being interrupted by sportier driving?
Is this why, after I turned the ignition off and then res-started, and subsequently again drove in a sporty fashion there was no issues (because I started off driving sporty!)?

If so, then that means that I cannot go from "normal" to "sporty" in the same trip. - that can't be the case surely?

or is this perhaps linked to driver assists being activated - like road traffic info displayed and lane keep assist?

Anyone got any clues?

And no I was not driving like a hooligan - but definitely did a few lane moves, dropped to 4th via paddle and accelerated causing some pops and bangs!

 

[Anonymous]

From your first post you've had the car for a couple of weeks. I would suggest it needs plugging into diagnostics to determine what fault codes are stored. If you purchased from a dealer or garage then give them a call.

 

[ToyCarMan]

Yeah, had the car 1 week today infact. I tried my old cheap XTRONS blutooth dongle with Car Scanner Pro but most functions don't read on the device. So I have ordered a better dongle. Should have it tomorrow. Can't wait to see what it shows.

 

[JAGBOB]

I have read your issue, just check the photo that you have the same setting. I might be wrong but worth checking. I find when in cruise control and boot the throttle it does not drop gears to boost speed. I will test again tomorrow and report back.

 

[ToyCarMan]

Thanks folks for looking over my post - much appreciated. So while I wait for my new blutooth dongle to arrive tomorrow I performed another little test. While sitting in Cruise Control at 65mph I activated Dynamic Mode. Everything appeared fine (dash red etc) however as soon as I applied more throttle I recieved the message shown in my previous attachment "OK to Drive with Caution, Reduced Performance". And yet in Drive or Sport Mode I can throw the car about no issue. So I think I may have narrowed things down to a Dynamic Mode issue. I must admit, when I owned my V6 when I engaged Dynamic Mode I felt a slight jolt along with it - whereas this V8 has nothing (bar the red HuD).

 

[gasgas]

why not phone the dealer for help?

 

[cj10jeeper]

why not phone the dealer for help?

I agree.
You clearly have a recurring significant issue on a newly purchased car.
Aside curiosity why not just have it recovered by the dealer or book it in and get it fixed?
Continuing to press buttons and drive isn’t going to help.

 

[ToyCarMan]

why not phone the dealer for help?

Well I'm just north of Edinburgh and they are in Northampton. Ive already informed them of the issue and that I would keep an eye on it. I'll give the car a quick scan before reporting anything else to them. My hope is that it can be fixed at a Jag dealer near me as I would hate to drive 6hrs back to then to hand it back for a refund.

Thankfully I have a 1 year "Jaguar Approved" warranty but I want to get as much info as possible before they insist on their own checks.

 

[Lunar]

You don’t have to take it to the supplying dealer - or indeed to a Jag dealer, if there is a good Indy garage near you who provides Jag warranty work too. You can always ask for the fault codes it reads out and I’m sure an Indy would be fine with showing you - whereas Jag dealers can sometimes be hard work now, with their meet and greet approach and not getting to talk with the tech or even the service manager.

 

[Kev]

Just get the thing booked in with someone who can deal with the Jaguar warranty as it’s only a week old. Be prepared for other ‘issues’ if your OBD reader can’t shut the session down when you’ve finished reading any codes

 

[ToyCarMan]

Thank you all so much for your time and valued feedback...

You don’t have to take it to the supplying dealer - or indeed to a Jag dealer, if there is a good Indy garage near you who provides Jag warranty work too.

Believe it or not, I actually live in a town surrounded by car garages and every time I rolled up with the V6 - they instantly baulked at the idea of working on it (outside of Tyres and basic MOT). They would often misdiagnose issues and simply refer me back to Jaguar specialists anyway. I had an extended warranty with MotorEasy and the garage network they use is abysmal and simply don't work well with warranty claims as they see them as a "hassle". They couldn't even carry out transmission oil replacement on the 8-Speed Auto-Gearbox. Although I am still weighing up the Pros/Cons, I may just bite the bullet and look to extend my pre-existing Pre-Approved warranty from Jaguar as most Independent Specialists are about 1hr drive away.

You clearly have a recurring significant issue on a newly purchased car.
Aside curiosity why not just have it recovered by the dealer or book it in and get it fixed?
Continuing to press buttons and drive isn’t going to help.

Well it is thanks to the curiosity of others on here over the years (fault finding, making guides etc for us all to benefit from) that I have learned a lot.
I guess it is the Computer Scientist in me that simply wants to know and understand for myself (and then share here - assuming anyone is even interested).
Plus - I would like to know what exactly it is that I am reporting - I find it helps save a lot of time.

I am now away to press further buttons...

 

[JAGBOB]

Thanks folks for looking over my post - much appreciated. So while I wait for my new blutooth dongle to arrive tomorrow I performed another little test. While sitting in Cruise Control at 65mph I activated Dynamic Mode. Everything appeared fine (dash red etc) however as soon as I applied more throttle I recieved the message shown in my previous attachment "OK to Drive with Caution Reduced n, Performance". And yet in Drive or Sport Mode I can throw the car about no issue. So I think I may have narrowed things down to a Dynamic Mode issue. I must admit, when I owned my V6 when I engaged Dynamic Mode I felt a slight jolt along with it - whereas this V8 has nothing (bar the red HuD).

I have tried to simulate your issue today. When driving with or without cruise control at 65mph and in 8th gear in D or S mode and hit the throttle the car doesn't drop any gears but slowly increases speed. When in D or S mode in 8th gear and hit the throttle and then slip in to S or D then the gears drop and speed increases fast. I have not had an issue with any error codes or dash info. It doesn't alter anything when the cruise control is on or off in either D or S mode. If its still under the Jag warranty I would get sorted at a JLR or Indy garage.

 

[ToyCarMan]

Yeah, I tried to replicate it again today and couldn't. The car behaved and performed like a dream. Although I'm not noticing as much of a difference between Normal and Dynamic as I did in my V6. Still waiting on my OBD2 dongle.

Thanks for the comment on "other issues" yeah I experienced them with Low Batt on the V6. I'll be sure to close a session before I unplug.

 

[JAGBOB]

Yeah, I tried to replicate it again today and couldn't. The car behaved and performed like a dream. Although I'm not noticing as much of a difference between Normal and Dynamic as I did in my V6. Still waiting on my OBD2 dongle.

Thanks for the comment on "other issues" yeah I experienced them with Low Batt on the V6. I'll be sure to close a session before I unplug.

I have checked some other JLR forums with your dash info and it seems to with bad battery condition or connections on I and F pace cars.

 

[ToyCarMan]

Well I ran my OBD2 Scanner over the car and it helped throw up a "Gearbox Fault" message on the dash.

I have contacted the retailer and will hopefully hear back soon regards their recommendations. I have to say they have been amazing and my hope is that they will cover the costs to have it rectified at my local Jag dealership - otherwise its a long drive back to Northampton and then a flight back to begin car - hunting again.

As part of my reccie on the car, I had a nosey under the boot liner to check the cabling running to & from the battery - all seems solid (except one rogue white plug) - I've circled it in green. Not quite sure what its for and if its meant to be connected to anything or not. Although it looks like it could, it does not stretch far enough to connect to the unit that has the pink and yellow plugs connected (but it does look like it wants to join them!)

Fingers crossed for a positive solution tomorrow.

 

[Billymcmred]

Yeah, I tried to replicate it again today and couldn't. The car behaved and performed like a dream. Although I'm not noticing as much of a difference between Normal and Dynamic as I did in my V6. Still waiting on my OBD2 dongle.

Thanks for the comment on "other issues" yeah I experienced them with Low Batt on the V6. I'll be sure to close a session before I unplug.

I have been following your post and think you have to be very careful, you have maximum protection under consumer rights act within the first 30 days after purchase once 30 days have passed you lose the right to return for full refund, “hoping the dealer will refund your costs” is a big ask imo the main dealer are just hoping you don’t reject the car, personally I would reject get your money back and start looking again you have lots of choice especially at main dealer prices