Xsara HDI 110 LX - intermittent running problem

gramar · Unread post by **gramar** » 26 Aug 2009, 21:27

Hi I'm a newbie to this site.

I bought my Xsara a year ago. It's a 52 plate with only 41k miles. It had 28k when I got it. From day one I realised it was running a bit sluggish compared to my other car a VW Polo Estate TDI 90. I carried on until a few months ago when the engine management light came on one day and then got it diagnosed. Up came code P0235- boost pressure sensor signal too high. This was reset but defaulted soon afterwards. When run like this the car pinks at low revs in the first three gears and there is a flat spot just off idle. The car also lacks torque and slows up long hills.

I've been back again for a further diagnosis and this time a different code was found P0246 - Pressure converter: boost pressure control deviation.
We then did a road test and the engine management light came on - car resorted to full limp home mode and a repeat of the code 0235 - boost pressure sensor signal too high. Faults reset and the car drove superbly until -- next morning when it was back to square one. The Bosch man is consulting with Bosch on this and he thinks it might be the boost sensor but from the live data he has recorded it's more likely, he thinks to be a faulty boost control regulator or the turbo itself. In other words he doesn't know!!

Poke and hope seems the only fix on offer so we are going to fit a new boost sensor on Friday to see if that works. Another garage I spoke to today suggested a blocked EGR valve may be the cause of the problem.

Has anyone got any bright ideas? or maybe experienced the same problem and knows what the cure is? I'd be very grateful for any help.

steelcityuk · Unread post by **steelcityuk** » 26 Aug 2009, 21:43

Hi,

It's a silly question if you had a Bosch specialist look at it but does the wastegate move freely and has a vacuum gauge been used to test for leaks/solenoid problems?

I would think that a HDi in a Xsara would be quite frisky.

Steve.

gramar · Unread post by **gramar** » 27 Aug 2009, 06:05

It's a silly question if you had a Bosch specialist look at it but does the wastegate move freely and has a vacuum gauge been used to test for leaks/solenoid problems?

Thanks for your prompt reply. the answer to your question is no. Is it easy to check the wastegate use the gauge as you describe? What's involved?

I live in Suffolk and the guy (is in Cambridgeshire just down the road from where I work) I'm using came recommended but only because he is from a small village garage with a centuries old reputation for good friendly service. He has wondered whether the problem could be caused by a blocked carboned up turbo - seeing as the one previous owmner was a retired farmer who only covered 26k miles in 6 years.

I've tried two other garages but this one is the best so far. What frustrates me is that no one yet has said "Aha what we need to do is !%£!and that will sort it". It's cost me about £100 so far to get noowhere and I'm resistant to wasting to much money when the 'experts' haven't a clue. I'm otherwise happy wth car and I'm sure you're right it should be frisky and I'd love to experience it running right.

With the cars I grew up on it was far easier to fix a fault yourself for next to nothing. Progress? I think not.

I wonder if there is another 'expert' in my area? The guy I using is Cambs injector Services and is the only easily accesible Bosch specialsit I have found.

steelcityuk · Unread post by **steelcityuk** » 27 Aug 2009, 08:35

Ah I see.

Well I haven't worked on a Xsara HDi but I would say it has to be similar to either the Xantia or the C5.

First I'd check the simple stuff. If it is a sticky wastegate pivot then the car will need to be up on ramps so that you can see up between the engine and the bulkhead. On the turbo you find a metal rod that goes from a metal can to a small metal crank. See photo. What I suggest you do is try to remove the circlip holding on the rod to the pivot then 'exercise' the pivot backwards and forwards working in some copper grease. Then grease up the end of the rod and refit. Take the car for a drive and see if that's fixed it, if not then you'll be looking at a fault with either the vacuum control solenoids/piping or pump. A vacuum gauge can then be useful to see if the solenoid is applying control to the wastegate.

The photo below is actually of a XM 2.0 Petrol Turbo but you can clearly see the wastegate rod and the copper grease that's been applied to the pivot.

Steve.

gramar · Unread post by **gramar** » 28 Aug 2009, 20:29

Steve

Thanks for your replies. The boost pressure sensor was replaced today. The tip on the old one was coated in oil which may have affected its ability to send the correct information to whichever computer controls the boost. Interestingly whilst the car runs sweeter so far, it's still 'pinking' noticeably in the lower 3 gears from between tickover and 2000 rpm - oh did forget to mention that in my original post, I think I did. We took a look at where the EGR valve is too and it's in the most inaccessible place you could imagine. It's adjacent and slightly below the brake master cylinder tucked under the top left side of the bulkhead as you look in from the front of the car. How on earth anyone can remove it to clean -- I'd love to know??? 'cause that's the next item I'd like to check. The Bosch man thinks it'll be mighty difficult and probably expensive to have a garage do it. It's not a difficult proposition to clean it provided I can reach it -- any ideas?? anyone?