Restricted performance when accelerating - intermittent (back again)

[Coolcity]

Basically as the title says, when I accelerate quickly, for example when overtaking somebody, usually from about 40 mph, I get the Restricted Performance warning light come on and reduced performance. 

The problem I have is it's intermittent. It first happened about 6 weeks ago during what I admit was pretty aggressive overtaking. After I stopped and turned the car off, when I went back to it an hour later it was perfectly fine again. 

During the next 4 weeks it drove as normal, including a couple of hundred motorway miles and 3 days in the Lake District at various speeds including some fast overtakes (on dual carriageways etc.) and at times pushing it harder than I have at any time the issue has occurred. No problems at all. So it's not happening at any specific speed or engine temperature.

Then last Sunday it happened again, once again when accelerating fairly quickly from about 40 to 60, and again today. Neither of the last 2 times was particularly fast or aggressive, just what I would call a normal acceleration when overtaking.

On each occasion the car has warmed up for at least 10 minutes, in fact last Sunday we'd been out for the day and drove about 60 miles at various speeds before the problem occured so I'm not pushing it from cold. I tried stopping and turning off the ignition today to see if the warning cleared straight away, but it didn't. But if I leave it for a while and go back to it, it runs perfectly fine again. 

Anybody have any ideas? 

[Raistlin]

Possibly a small crack in one of the intercooler end casings. Only opens during acceleration (high turbo pressure).

[Coolcity]

Thanks, sounds like a good place to start. 

[Big John]

Hi

My starting point would be to read the DTC codes as without them you really are guessing.

John

 

[Raistlin]

Absolutely right of course John. But in this case I was speaking from very recent experience 😉

[Coolcity]

Yes, I'm going to have to get a reader. 

I've had a quick look at the pipework round the cooler, everything looks to be in very good order, all clean and dry. Thinking about it, had that been the problem I would have expected it to occur more often, especially running around Cumbria. Checking the mileage, it's only happened 3 times in around 1000 miles. 

I know it's guesswork at this stage but I'm just considering possible easy to find causes at this stage until I can get it looked at properly. 

[Coolcity]

Would this be the sort of thing I need? Seems like a reasonable price:

Jaguar XF Diagnostic Scan Tool & Reset Fault Code Reader - iCarsoft LR V2.0 | eBay

[Coolcity]

Oh, one other thing I've just remembered. A couple of weeks ago the "Service required" light came on. According to the paperwork it was last services around 2500 miles ago, reading 50960, back in February but that's before I got it. The previous one was an Oil service at 47,600. I don't know if there's any connection with the Restricted warning. 

[Raistlin]

The ICarSoft LR2 or 3  is very popular with Jaguar owners. Sort of a half way house between a bog standard code reader and the Jaguar OEM diagnostics.

 

[Coolcity]

Thanks, that's helpful. I've ordered one, looks like it's worth having as it would probably cost at least that if I took it in for a diagnostic, and that should at least give me some idea of what's happening. 

[Tomato]

Service light has not been reset properly if it been serviced 2500 miles or it does trigger every 12 months if set that way as I discovered recently 😀 

[Coolcity]

I wondered about the 12 month thing as that's how it worked on my last car, but most previous services seem to have been done around February, and then there was another one in May by the garage I bought it from. There doesn't seem to be any obvious reason why it would come on now. 

[Bigvic]

On diesels, the service light can come on when the car thinks there is too much diesel dilution in the engine Oil

This could indeed be related to your rp if there is a crack in your intake manifold allowing your car to run too rich

[Coolcity]

Thanks, that's interesting. I'll get that checked too but I'm going to wait until I get the diagnostic gadget, hopefully early next week. 

I ran it again today, accelerated quickly right up to over 90 and ran it for a few minutes, no problem at all. Then on the way back I accelerated more aggressively and got the warning at around 4300 revs, higher and faster than when it's kicked in before. 

Even in RP mode it will still run up to 80, and probably on but it's obvious there's a power drop. Definitely feels like a vacuum leak or something related. 

Edited September 10, 2021 by Coolcity

[PaulT]

Also change the fuel filter, a partially blocked one can cause intermittent RP (I have the T Shirt).

[Coolcity]

I wondered about the fuel filter as it tends to pop up regularly in threads. 

Anyhow, I'm still waiting for the code reader to arrive (by the way, where's the plug point for it?), so I've contacted the dealer I got it from as it's still under warranty anyway, and they're going to take a look at it on Monday. 

For the last 200 miles or so the warning hasn't come on, I've done motorway speeds but avoided "flooring" it. 

I did get another warning light last night, Park Brake warning came on as I pulled up after a short 8 mile motorway trip, but cleared itself when I restarted it on the return trip and didn't come in again when I got home, so it might have just been a glitch.

The brakes do grab ever so slightly at the last second as I brake to a halt though, discs and pads were new all round when I bought it 3 months ago so I put it down to that, but they should surely have run in by now?

[Raistlin]

"Anyhow, I'm still waiting for the code reader to arrive (by the way, where's the plug point for it?)"

 

The OBD2 connector is under the fascia where your right knee would be when driving.

[Old Peter]

6 hours ago, Coolcity said:

I wondered about the fuel filter as it tends to pop up regularly in threads. 

Anyhow, I'm still waiting for the code reader to arrive (by the way, where's the plug point for it?), so I've contacted the dealer I got it from as it's still under warranty anyway, and they're going to take a look at it on Monday. 

For the last 200 miles or so the warning hasn't come on, I've done motorway speeds but avoided "flooring" it. 

I did get another warning light last night, Park Brake warning came on as I pulled up after a short 8 mile motorway trip, but cleared itself when I restarted it on the return trip and didn't come in again when I got home, so it might have just been a glitch.

The brakes do grab ever so slightly at the last second as I brake to a halt though, discs and pads were new all round when I bought it 3 months ago so I put it down to that, but they should surely have run in by now?

Hi Gary,

I am in a similar position and did a drive this morning to see if I could get rid of the Yellow warning light.   I didn't get rid go it and my OBD2 said "No Codes."  I will buy a better one!

The AA engineer  was able to find the code which was P0404 — the EGR valves need cleaning.

Good Luck,

Peter.

[Coolcity]

13 hours ago, Raistlin said:

"Anyhow, I'm still waiting for the code reader to arrive (by the way, where's the plug point for it?)"

 

The OBD2 connector is under the fascia where your right knee would be when driving.

Thanks, that's helpful. 

[Coolcity]

On 9/19/2021 at 11:34 AM, Old Peter said:

Hi Gary,

I am in a similar position and did a drive this morning to see if I could get rid of the Yellow warning light.   I didn't get rid go it and my OBD2 said "No Codes."  I will buy a better one!

The AA engineer  was able to find the code which was P0404 — the EGR valves need cleaning.

Good Luck,

Peter.

Thanks Peter. 

When I got it the DPF needed clearing, and I did a 60 mile motorway trip a couple of times and still couldn't clear it. I bought a 3-pack of STP DPF cleaner fuel additive, did another 40 mile trip and that clears it and its been fine since. 

On that basis it might be worth adding a can of EGR cleaner, can't do it any harm to try. That said, the fault warning light seems to kick in under hard acceleration, so I would be surprised if it was anything to do with the EGR system as I thought they only kicked in under low loads? It could be though as its only done 53k but I get the feeling a lot of it must have been short town journeys. 

Anyway it's going in to the dealer I bought it from in the morning so I assume they'll put a fault code reader in it and take it from there. 

Will update when I have more details. 

 

[Coolcity]

OK, so I've got the iCarsoft LR v2.0 diag tool and done a quick check, though this is only at idle, not on the move. assuming I'm using it correctly it came back with 9 codes. I was advised to use the 2010-11 setting as it's an 09 plate but a 2010 Model Year.

 

P244B – DPF differential pressure sensor – circuit high

P2458 – DPF regeneration duration

P00BD – Mass or volume air flow A circuit range/performance – Air flow too high

P1247 – Turbocharger boost pressure Low

P2263 – Turbocharger boost system performance

P0235 – Manifold absolute pressure sensor circuit

P22D2 – Turbocharger turbine inlet valve stuck open

P22CF – Turbocharger turbine inlet valve control circuit – OPEN

P244B – DPF differential pressure sensor – circuit high

P2458 – DPF regeneration duration

*P1571 – Brake switch malfunction./Brake switch.

 

So from that I assume there's a stuck or failed valve on the turbo? 

 

* The last one is what I assume is causing the amber PARK BRAKE FAULT to come on. This is a bit odd as the last time,. it came on as I pulled up (but before putting the parking brake on). this time it came on as I pulled away. Car drives normally, brakes don't feel as though they're dragging or binding until I'm almost at a halt, when they seem to grab a little, so I'm not sure if that's connected in some way or not. 

[O.T.H]

 with all those faults showing I would check how old the battery is and replace ????

[Coolcity]

Definitely not the battery, readings and performance of the battery are fine and well within parameters. 

Most of that list appear to be something to do with pressure or vacuum, so probably linked. Besides, a worn or defective battery doesn't appear (to me) to be something that would cause a restricted performance issue on hard acceleration. Sounds to me more like what it says, a valve or port stuck open. 

[Bigvic]

Delete the fault codes and go for a run in the car

Some of these codes might be old, historical codes

When you’re finished your jaunt, read the codes again to see what’s still there

[Bigvic]

You’re right though…

It does look like a vacuum leak