X150 coupe: Talk me out of it

X150 coupe: Talk me out of it

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remedy

1,680 posts

194 months

Saturday
quotequote all
Good timing for this post to be resurrected.

I think I fixed mine today. It was a bad earth on post G03 that is behind the engine fuse box under the windscreen on the passenger side. The nut felt loose and the connectors were corroded, but when I tightened the nut up the stud sheared off. It looks like it is in the path of the water drain from the windscreen.
I made another earth point and got everything reconnected.

I had installed another fuse box as my old one wasn't putting out power to the restraints module or the pedestrian protection module.
Not sure how this was linked. The new fuse box had power to those pins. Was this the system locking itself out?

Either way, I bought a SDD system as Sytner Jag literally gave up. I recoded the aux fuse box today, cleared the codes and it started fine.
Still got my stupid TPMS fault so will sort that tomorrow z hopefully.

But fingers crossed it's done. Over a year without a car, all because of a corroded earth making the car think the bonnet airbags had fired.
And it confirmed that main dealers are utterly useless at real fault finding.
I taught myself to interpret the circuit diagram for the car, worked out that a deployed airbag would cause my symptoms and traced it to the bad earth for the PPS.

tberg

602 posts

64 months

When I had problems with the TPMS system, if I inflated the tires to about 40psi, drove the car a bit and then lowered the pressure back to normal, my TPMS faults disappeared. Other members of the Jaguar forums have reported similar success with this procedure.

remedy

1,680 posts

194 months

Thanks, will give that a try.

GeniusOfLove

1,580 posts

15 months

remedy said:
Good timing for this post to be resurrected.

I think I fixed mine today. It was a bad earth on post G03 that is behind the engine fuse box under the windscreen on the passenger side. The nut felt loose and the connectors were corroded, but when I tightened the nut up the stud sheared off. It looks like it is in the path of the water drain from the windscreen.
I made another earth point and got everything reconnected.

I had installed another fuse box as my old one wasn't putting out power to the restraints module or the pedestrian protection module.
Not sure how this was linked. The new fuse box had power to those pins. Was this the system locking itself out?

Either way, I bought a SDD system as Sytner Jag literally gave up. I recoded the aux fuse box today, cleared the codes and it started fine.
Still got my stupid TPMS fault so will sort that tomorrow z hopefully.

But fingers crossed it's done. Over a year without a car, all because of a corroded earth making the car think the bonnet airbags had fired.
And it confirmed that main dealers are utterly useless at real fault finding.
I taught myself to interpret the circuit diagram for the car, worked out that a deployed airbag would cause my symptoms and traced it to the bad earth for the PPS.
That's great news. I know the X350 had issues with earthing points breaking off, given the commonalities I don't suppose it should be a surprise if X150 has the same problem but this is the first time I've ever read about it.

Hopefully you can now just enjoy the car. TPMS systems are a massive pain in the arse, they're always complaining. You can unlock engineering mode on SDD and edit the cars feature set to turn the system off if all else fails.

remedy

1,680 posts

194 months

Day 1 and it is ok. Took it for a spin, some fuel and to pump up the tyres as suggested by tberg.
As much as a pain in the ass it is, I love it and my next challenge is to avoid the wife's demands to sell it.

I'm looking forward to hearing how the Cornwall road trip went.

Patrick Bateman

12,243 posts

177 months

Diderot said:
Thanks Summit - so glad you’re loving it. On Monday we depart for Cornwall. First properly long run for the XKR. Looking forward to it. BTW, mine has leather roof lining , was that an option over the Alcantara?

Apropos of tyres. Had the Conti Sport Contact 7s fitted this week. Done 11 miles so far, so looking forward to properly bedding them in. Findings so far are: comically, nay, hilariously better traction, even with the stickers on than the ditch finder Dunlops, and a much more pliant ride it seems. Will report back from the West Cornwall trip from the South Coast next week.
No coincidence you've found the same as myself. biggrin

GeniusOfLove

1,580 posts

15 months

Patrick Bateman said:
Diderot said:
Thanks Summit - so glad you’re loving it. On Monday we depart for Cornwall. First properly long run for the XKR. Looking forward to it. BTW, mine has leather roof lining , was that an option over the Alcantara?

Apropos of tyres. Had the Conti Sport Contact 7s fitted this week. Done 11 miles so far, so looking forward to properly bedding them in. Findings so far are: comically, nay, hilariously better traction, even with the stickers on than the ditch finder Dunlops, and a much more pliant ride it seems. Will report back from the West Cornwall trip from the South Coast next week.
No coincidence you've found the same as myself. biggrin
Seem to wear well too, 8k miles on the rear of my XKR and I'd say they'll do 12k and maybe more.

MikeM6

5,087 posts

105 months

I picked up my XKR on Saturday and I was expecting terrible traction on the Dunlops, however strangely I have had no real issues so far. Granted, it has been bone dry and warm, so I suspect wet weather may be an issue, but coming from the M6 on Conti SportContact 7, I was expecting to be squirming a lot.

Patrick Bateman

12,243 posts

177 months

Report back after your wet experience.


MikeM6

5,087 posts

105 months

Patrick Bateman said:
Report back after your wet experience.
As kinky as that sounds, I will.

GeniusOfLove

1,580 posts

15 months

Yesterday (09:06)
quotequote all
MikeM6 said:
I picked up my XKR on Saturday and I was expecting terrible traction on the Dunlops, however strangely I have had no real issues so far. Granted, it has been bone dry and warm, so I suspect wet weather may be an issue, but coming from the M6 on Conti SportContact 7, I was expecting to be squirming a lot.
They are fine in the dry. I don't want to sound dramatic but be very cautious in the wet, their limits are so much lower than you'd ever expect it can really catch you out. I had a diesel XJ putting the tail out at 20-25mph on roundabouts on OE Dunlops, once you expect it you can enjoy it but it's a real shocker the first time it lets go at what feels like walking pace.

A lot of the time the forum noise on the OE tyres something comes with is absolute exaggeration and nonsense, but in this case I'd have to wholeheartedly agree that they're appaling tyres with chinese ditchfinder level wet weather performance. I can't believe it never showed up in testing.

MikeM6

5,087 posts

105 months

Yesterday (12:09)
quotequote all
I appreciate the heads up and will heed the warnings, I'm sure I'll have plenty of wet weather experience soon!

Does the traction control catch it ok? Just wondering if my non petrol head wife will be easily caught out.

GeniusOfLove

1,580 posts

15 months

Yesterday (12:41)
quotequote all
MikeM6 said:
I appreciate the heads up and will heed the warnings, I'm sure I'll have plenty of wet weather experience soon!

Does the traction control catch it ok? Just wondering if my non petrol head wife will be easily caught out.
Yes it has always caught it for me so far...

I threw them in the bin with loads of tread left after the 2nd unpleasant experience.

Patrick Bateman

12,243 posts

177 months

Yesterday (12:47)
quotequote all
Don't bank on the traction control, I consider it a fairly 'loose' system compared to old BMW's I've had.

Re the Dunlops in the wet, I had one instance in particular on my commute accelerating out of a 40 into a 60, damp conditions (with trees nearby inevitably not helping), 3rd gear brisk acceleration but not absolutely gunning it and the rear stepped out at around 4000rpm to the point I completely shat myself.

Ordinarily you'd expect to see a flashing light on the dash and a little squirm in that scenario.

Another much less scary moment was trying to join a wet roundabout, slight uphill and one of those 'I can just nip out quickly here' moments. Slightly too much throttle and I was left on the spot, rear wheels lit up looking like an absolute tit. biggrin

I too used to wonder when I read on forums about 'Dunslips' and how much of it was exaggeration. None of it based on experience.

8bit

4,905 posts

158 months

Yesterday (22:50)
quotequote all
My second XKR (pre-facelift 5.0) came with the Dunlops on the rear - they deserve all the stick they get IMHO. I had them changed for Vredestein Ultrac Vortis as soon as I could. The Dunlops were OE fitment on the original X150 XK 4.2 making about 300bhp, back in late 2005. They may have been OK for that but they're not for anything much more powerful than that.

Someone mentioned Conti SC7s - I never had them on my XKR, had Michelin PS4S on that but I have the SC7s on my C63. Different cars obviously but I suspect the Michelins may have the edge in the wet. Both seem very grippy in the dry. I'm not unhappy with the Continentals but when I need new rears I'll possibly go for Michelins.

MikeM6

5,087 posts

105 months

Looks like I'll be finding out for myself about these Dunlops this morning, bloody raining again.