I got a red Restricted Performance warning light yesterday

No DPF warning and its been driven for long distances before it came up. When I accelerate I can hear a hissing sound when the warning is on.

Also not sure if this is related but when I turn the steering wheel near full lock, I get a weird whirring sound.

Going to get it in with the dealer next week but anyone have an idea what it could be if its not the DPF? Could it be costly and likely covered by warranty?

 

Hopefully others will have suggestions too, but restricted performance warning + hissing sound under load sounds like a vacuum failure.

There are a couple of more obvious things to check - the welded plastic part on the exit of the intercooler can split along the seam (very common fault on the diesel X351 and XF), or the big hose attached to it can develop a split. Neither is always visible when cold, but can be easily diagnosed by having someone hold the revs at about 3k while you check under the bonnet. I had the former replaced out of warranty at a main dealer for around £500 including labour. That fix should be covered under the Jag factory and extended warranties, but the hose might not be if the factory warranty has expired.

 

Thanks xDave, £500 sounds like an awful lot for what sounds like replacing a hose, was it from the main dealer?

 

I can't find the invoice to check exactly what parts where replaced, and what proportion of that was labour, but I recall it was not the hose in my car that had split but either the intercooler housing or something that fits onto it requiring replacement.

 

Have you read the fault codes? Opened the bonnet to look?

 

Thanks, lets see what it could be

Not sure how to read fault codes, do I need some equipment?

Checked under the bonnet and couldn't see anything loose or worn.

 

It is most likely either an intercooler hose. Or one of intake manifolds leaking. Which are weak parts in the engine. I had manifold leaking - dpf was on very often due to a rich mixture of fuel. My friend has same car - he had side of intercooler leaking - restricted performance was very often too together with dpf

 

Spoke to a garage, they said on the x351 it is most likely the C Cell Valve, that gets clogged, no idea what that means, but will send it in

 

Yes, it's a mandatory tool on any modern car if you're going to DIY.

 

Thanks, where can i obtain one for the x351?

 

Search on this forum for code reader, the ELM 327 is very popular.

 

thanks so much

 

Turns out the entire intercoolers gone, garage quoted £640 including labour, they spoke to my warranty provider (AutoTrust) who said its not covered, seems a bit weird as its not parts and labour, going to chase it up with them.

Anyone else had something similar?

 

I'm glad you got it diagnosed. Was it because it had split open at the plastic welded seam? £640 allowing for part and labour inflation sounds about on par with what I paid a couple of years ago.

Which AutoTrust warranty do you have? Looking at the policy booklets on their website:

Formula X appears to include it by virtue of it not being excluded.

Formula 1 specifically covers failure of all cooling components except those considered consumable (hoses and pipes). Whether you could class the intercooler as a cooling component or not I am unsure. I would argue it is cooling the air so should be covered. You've nothing to lose by arguing for it.

Formula 2 would not cover it.

 

Thanks for replying because that's exactly what i was thinking when i read the warranty book, i have formula one cover so I feel they are trying to fleece me, will ring them up and ready to go all the way to a small claims court if they refuse

 

Using this logic the A/C system should be included too. Don't think you'll get far with claiming an intercooler as the same thing as a radiator or coolant pump.

 

IMHO the intercooler is part of the "sealed" induction system and like the supercharger should be covered, unless it's failure was due to a ruptured external hose.

 

Warranty says:

Cooling system – Internal failure of all components, except belts, hoses, pipes, core plugs and failure due to clogging and sedimentation.

They are telling me fibs, because they havent excluded it, and its not wear and tear.

 

But it's not part of the engine cooling system any more than the A/C system is.

 

If it's the kind of intercooler I think then it's not at all like the a/c and I would expect it to be covered.

To find out for sure may be painful (read like a legal person) and if the warranty people refuse the claim you may have to get a qualified (certificated?) engineer's report, face the warranty firm with it and if need be issue a court claim. Fairly easy but a pain. (Easiest is often MCOL - money claim online.)