HELP!!! 2.7 Twin turbo problems

[marmight]

Hi can anyone help please. Symptoms are, lack of power on acceleration, then clouds of black smoke out of the exhaust and plenty of power when this clears. It's an intermittent problem which can vanish for a couple of days and then re-appear. Switch the engine off and it will vanish once again - sometimes... Driving me looney as I don't know if I am doing any damage to the CATS.
Fault code readings are:

P004b
P0299
P0402.

I know it's something to do with the B turbo solenoid and the other two I think are after effects from the first problem - turbo boost fault and MAF sensor readings.

Please help as I love the car and need to get it fixed.

Thanks
Martin

[J44EAG]

Try typing the fault code straight onto your browser search engine bar. There are many different sites giving specific information on various codes. Some codes seem more buried than others. In some cases, the more obscure codes will need some detective work to source the information you need. The P004b code seems to be one such code.( a quick look taken just now)

The diesel is a complex unit and on many occasions really does need professional attention to get fixed quickly and cost effectively. You will be able to source some reliant information but will possibly need dealer level equipment to track down the root cause of the issue.

The turbo actuator rubber poppet valves are a well known source of turbo issues. The valves can be vacuum tested in situe. Dave Marks recommends a test every six months or so in view of their propensity to split.

Can any of the diesel guys here be of further assistance please?

Sorry I can`t be more helpful. My diesel experience is somewhat limited.

Mike

[Montana5]

I'm no expert but sounds to me like the infamous EGR Valve.
Code P0402 is Exhaust Gas Recirculation Flow Excessive Detected.
take a look at this link...
http://www.datsc.com/tabid/122/OBD-Erro ... fault.aspx

Doug.

[raysearles]

Hi Martin,

I think Doug may be correct here; before my XF I had a 2.7D Sport S Type - which went into limp-home mode one afternoon in the middle of Brum, effectively shutting down the turbo and leaving you with minimal power.

It cleared it self the next day but soon came back and running it through the local dealers diagnostics the EGR valves where the culprits. Replaced and worked fine - I would try and find an independent to do the tests and work if you can, like XJK or Dave Marks as there rates are a lot cheaper per hour than the dealers.

[SteveKK]

To find a decent independent post with your location and I'm sure someone on here will be able to point you in the right direction.

I had an issue earlier this year that my local garage took weeks to fix, but I'm sure the local independent I've now found, XJ Motors near Chertsey, would have fixed in days. I will still use my local garage for regular work, as they are good, but fixing some issues with a Jag need a very good specialist.

Regards,
Steve

[jeff1954]

Hi Steve
Sounds like either the Poppet Valves or the EGR's. South Staffs 4x4 show you how to blank the EGR's off using a kit off ebay obout £20 00. Hope this post is not to late.

Jeff

[marmight]

Many thanks for all your replies. I would seem that the culprit is the DPFE sensor (I think that is what it is called. Replacement to be fitted in a couple of days and I will report back. the general consensus is that EGR valves just don't go wrong - not my thoughts but if you read enough reports from around the world this is what keeps on coming up.
Anyway, I've deduced that the third code is where the problme lies as it is so intemittent. This coupled with the fact that both EGR valves where thoroughly cleaned and 24 hours later the problem returned. I've used the cat twice over the weekend with no problems at all. I, therefore think it's not the EGR valves, but the cheap and nasty sensor which is breaking down under heat and pressure. I have heard that this is standard Unipart part that is used on the Ford Focus - they have loads of EGR problems which are also attributed to this sensor.
We shall see and I will keep you posted on the outcome. I do use a independent Jag engineers in Coventry, one that I've used for years and have every faith in.

montana5, brilliant page, full of information about these sensors. Thank you.

Many thanks

Martin

[marmight]

The mystery deepens. Apparently, the early 2.7 diesel engine didn't have a dpf sensor...so what makes the egr and turbos work then?
Anyone any ideas before I go down the seemingly expensive replacement of egr route.

Cheers

Martin

[jeff1954]

Like I said Martin if it is the EGR valves you can blank them off using the kitt off ebay.
Have a look on South Staffs 4x4 web site on this matter as the Land Rover and Range Rover use the same engine.

Jeff

[raysearles]

Martin,

I would get the codes and the problem checked out by an independent Jaguar specialist before you start blanking off parts of the vehicle that were designed for a purpose.

If you need help locating one in your area give Graham, James or Mark a call in the JEC HQ and they should be able to steer you in the direction of someone who can use their diagnostic equipment to analyse the extent of your problem and recommend the treatment.