Fault code advice needed

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andypryce
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Fault code advice needed

Postby andypryce » Fri May 13, 2016 11:54 pm

Hello all, advice needed please. I developed a rough running along with fault code P0171 (lean full mixture bank 1), took to to my trusted mechanic who did a smoke test and diagnosed an air leak from EGR valve. A refurbished valve was purchased from Eurojag, which he fitted, but fault code persists and still not running properly. Any ideas people? Am going to book it in to Jag Autos in Everton for a look, but any thoughts in advance would be useful.

andy
andy

2006 XK

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J44EAG
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Re: Fault code advice needed

Postby J44EAG » Sat May 14, 2016 3:00 am

I had 171 and 174 together which indelicate Bank 1 and 2, Andy. That was a general leak so pointed to something up stream of the throttle body. That turned out to be a rotten pipe from the cowhorn manifold on the pressure side of the super charger. The pipe had aged and been blown off the cowhorn stub pipe causing a massive air leak and leaning off both banks.. Easily fixed in the end.

171 alone indicates lean on one bank only. I would suspect perhaps one of the cowhorn to inter cooler gaskets which are easily tightened just by removing the engine cover and tightening the bolts which cleat the cowhorn outlets to the inter cooler bricks with a 10mm spanner. Alternatively it could perhaps be a loose inter cooler brick bolt or two from the gasket between the cooler brick and the cylinder head or duff inlet gasket. Eight bolts on each side hold the inter cooler bricks to each head. To get to those, I believe the charger needs to come off the top of the engine to gain access. That isn`t a nice or quick job.

Conceivably though, I suppose it might just be a lamda sensor breaking down. PTJS 1 has a good insight into this type of fault. May be he could pass comment.

Sorry to be less than precise with this question, Andy. The above is my rather limited take based on what I`ve learned since getting my car.

Mike
X350 Co-ordinator

2004 XJR

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andypryce
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Re: Fault code advice needed

Postby andypryce » Sat May 14, 2016 8:00 am

Cheers Mike, have followed the stuff you have been doing with yours, quite amazing!

andy
andy

2006 XK

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andypryce
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Re: Fault code advice needed

Postby andypryce » Tue Jun 21, 2016 8:04 pm

Finally sorted...

New EGR valve, one new catalyst, one new lambda sensor, one new breather valve and new bolts on exhaust manifold clamps. £1500 worse off but all seems good now... :D
andy

2006 XK

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J44EAG
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Re: Fault code advice needed

Postby J44EAG » Tue Jun 21, 2016 10:39 pm

Interesting.

171 indicating lean on one bank only. More difficult to sort than 171 & 174 which indicate a Siamesed two bank leak.

I still have anon identifiable fault which occurs at either 30 seconds or 1min, 45 second frequently after start up. My iCarsoft 930i permanently hooked to the OBD port. Fault cleared and cancelled almost each and every trip after which it stays clear until I switch off and restart. Need to get this fixed before the next MOT in Feb 2017. May be just a bad connection on a plug somewhere or pressure pipe rot further to the area around the throttle body leading to the by-pass actuator or EGR valve.

Quite a list of replacements you have there Andy and most revealing.Thanks for sharing.

I could do with a visit to Tom Lenthal to fix these issues if I can`t do myself. Two months on a yacht refit has taken all my time and energy and the XJR has had to take a back seat....apart from new Avons on the rear. Great boots..no more wheel spin in the wet. My next shot is to fit a large inter-cooler rad, high flow Bosch pump, port the supercharger, elbow and cow-horn outlet and have Tom fit sports cats and an X-pipe in place of the H-pipe. Pump and inter-cooler to hand. Just need the time and physical capability. I must get my pal Dave Rex out of moth balls! A couple of weeks more on the yacht should free things up a bit.

Mike
X350 Co-ordinator

2004 XJR

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andypryce
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Re: Fault code advice needed

Postby andypryce » Tue Jun 21, 2016 11:24 pm

Thanks Mike, very professional outfit sorted it eventually, 'camco' in Warrington. Recommended to me by my usual mechanic. They specialise in engine management. Sounds quite glamorous being on a yacht for 2 months, or is that just your houseboat home?!
andy

2006 XK

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andypryce
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Re: Fault code advice needed

Postby andypryce » Tue Jun 21, 2016 11:25 pm

Sorry, just reread, yacht refit, not so glamorous
andy

2006 XK


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