XF restricted performance.

[milothepeanut]

Hello all. Some advice needed.

My XF 3ltr diesel is going randomly into restricted performance. The car has had a great deal of work done to it for its MOT and sat for around two months. Now it has thrown up the restricted performance message. It doesn't do it every time it is started but will go into it after a short time running. When trying to start it( when it decides to play up) it will suck suck suck suck at the pipe running from to throttle body and then clear to run smoothly but stays in restricted mode. Also at the MAF sensors I get a reading of 0 psi on the top and 16 at the bottom. It is sucking like a demon through the lower pipe and nothing on the top pipe.

Any ideas would be greatly appreciated.

[V12 Migaloo]

Whilst not an XF, I had frequent restricted performance on a use XJ 2.7. The car was under warranty, so the dealer changed DPF, EGR's, all coil packs, all injectors, then turbos and cats. It kept on going back as the problem still existed. Then they finally traced it to a crimped wiring section and changed that as well. This had been going on for a year or so, the dealer loaning me a Jeep in the meantime. When they finally fixed it they asked do I really want the car back or my money back, and me thinking that all the new items fitted it would be a good idea so I convinced myself to keep the car. Subsequently I had no restricted performance issues but less then 3 months after, the bottom end bearings turned wrecking the engine. I know that this has not helped you in anyway shape or form.

[Simpo Two]

V12 Migaloo said:

the dealer changed DPF, EGR's, all coil packs, all injectors, then turbos and cats..Then they finally traced it to a crimped wiring section

Good job you didn't end up paying many thousands for their guesswork when all it needed was 6" of wire.

[daphantom]

milothepeanut said:

Hello all. Some advice needed.

My XF 3ltr diesel is going randomly into restricted performance. The car has had a great deal of work done to it for its MOT and sat for around two months. Now it has thrown up the restricted performance message. It doesn't do it every time it is started but will go into it after a short time running. When trying to start it( when it decides to play up) it will suck suck suck suck at the pipe running from to throttle body and then clear to run smoothly but stays in restricted mode. Also at the MAF sensors I get a reading of 0 psi on the top and 16 at the bottom. It is sucking like a demon through the lower pipe and nothing on the top pipe.

Any ideas would be greatly appreciated.

Hi
I have the same car/engine. 2017 XF. Mine was/is doing this at he minute under heavy acceleration. Autospark told me it was secondary turbo (which kicks in at 3k revs). Took it to a turbo specialist. They said there was no obvious signs it is the 2nd turbo (would be a gamble taking it out and refurb or replace) Took it to a Jag indy highly recommended over here. He had it for a couple of days (im in N.I) and couldnt pinpoint anything! It was showing glow plug control module -low voltage, turbo underboost + exhaust gas temp sensor. As he would need to replace/work through the list (he was going on 2wks hols) he advised me to go to main dealer as they would have the parts onsite and could mix and match until solved. Their closest appointment is after the new year! So, at the minute the car runs fine if i stay under 3k revs, no more warning lights have came on. I was worried about no regens if in limp mode/restricted performance BUT seems to be ok 2mths down the line until i can get it sorted somewhere.Must say, not impressed at all but at least the car is driving as i need it every day

[Buffalo]

daphantom said:

Hi
I have the same car/engine. 2017 XF. Mine was/is doing this at he minute under heavy acceleration. Autospark told me it was secondary turbo (which kicks in at 3k revs). Took it to a turbo specialist. They said there was no obvious signs it is the 2nd turbo (would be a gamble taking it out and refurb or replace) Took it to a Jag indy highly recommended over here. He had it for a couple of days (im in N.I) and couldnt pinpoint anything! It was showing glow plug control module -low voltage, turbo underboost + exhaust gas temp sensor. As he would need to replace/work through the list (he was going on 2wks hols) he advised me to go to main dealer as they would have the parts onsite and could mix and match until solved. Their closest appointment is after the new year! So, at the minute the car runs fine if i stay under 3k revs, no more warning lights have came on. I was worried about no regens if in limp mode/restricted performance BUT seems to be ok 2mths down the line until i can get it sorted somewhere.Must say, not impressed at all but at least the car is driving as i need it every day

Your problem sounds different to the OPs (and his unfortunately sounds slightly more serious). Your issue is likely to be the valve that switches to the second turbo. Basically, the engine is so torquey that the second turbo is rarely activated so the valve gets crudded up. It is reasonable cost to replace this (i had to do it also), and then try to get the second trubo opened up periodically (over 2850rpm). However, i have to say my problem hasn't fully gone, but is very rare now. I turn engine off and on again and it always clears although the code is stored.

Edited to add that if you have any doubts on the battery condition then recommended to replace. An old battery just confuses the issues because it often flags upcodes that actually are fine. The two most common codes are turbo stuck open or closed. These are related to the valve.

Edited by Buffalo on Monday 16th September 20:37

[Buffalo]

milothepeanut said:

Hello all. Some advice needed.

My XF 3ltr diesel is going randomly into restricted performance. The car has had a great deal of work done to it for its MOT and sat for around two months. Now it has thrown up the restricted performance message. It doesn't do it every time it is started but will go into it after a short time running. When trying to start it( when it decides to play up) it will suck suck suck suck at the pipe running from to throttle body and then clear to run smoothly but stays in restricted mode. Also at the MAF sensors I get a reading of 0 psi on the top and 16 at the bottom. It is sucking like a demon through the lower pipe and nothing on the top pipe.

Any ideas would be greatly appreciated.

Have you checked the pipes for cracks? I've heard of them being an issue but not experienced myself. Google some of the jag forums for more info, but, unfortunately I don't find many of them very helpful.

[daphantom]

Buffalo said:

Your problem sounds different to the OPs (and his unfortunately sounds slightly more serious). Your issue is likely to be the valve that switches to the second turbo. Basically, the engine is so torquey that the second turbo is rarely activated so the valve gets crudded up. It is reasonable cost to replace this (i had to do it also), and then try to get the second trubo opened up periodically (over 2850rpm). However, i have to say my problem hasn't fully gone, but is very rare now. I turn engine off and on again and it always clears although the code is stored.

Edited to add that if you have any doubts on the battery condition then recommended to replace. An old battery just confuses the issues because it often flags upcodes that actually are fine. The two most common codes are turbo stuck open or closed. These are related to the valve.

Edited by Buffalo on Monday 16th September 20:37

Thanks Buffalo thats great. Its so frustrating because it wasnt as if im trying to avoid or scrimping on costs, it just seems there is no-one available to do it! Do you have a name for that valve that switches the secondary turbo? Ive had the car 10mths and tbh i rarely floor it unless overtaking on motorway - thats when it 1st appeared so, your analysis seems logical. Cheers

Edited by daphantom on Tuesday 17th September 16:28