Loud Knocking Xantia 1.9td Lexia fault update - SUCCESS

shaunlfc1 · Unread post by **shaunlfc1** » 03 Sep 2010, 21:11

I am not sure but we did have a page up on screen that showed coolant temparature to be 20 degree's and it also showed "counter 40".

I couldnt tell you if we were in the live parameters part of Lexia, Tony was driving it, if he see's this post he perhaps could comment!

How likely do you think its fuel pressure?

jgra1 · Unread post by **jgra1** » 03 Sep 2010, 22:19

Jim

i recognise that pic

Shaun, it will take you 20 or 30 mins to confirm the belt timing is ok?

Wanna know how?

John

shaunlfc1 · Unread post by **shaunlfc1** » 03 Sep 2010, 22:42

It had jumped a tooth wouldnt it retard the pump and not give me the noise?

But I am open to all suggestions, so will discount everything to get to the route of the cause. So please fire away!

Cheers,

Shaun

jgra1 · Unread post by **jgra1** » 03 Sep 2010, 22:51

ok dude, I had a wine

but.. disconnect battery.. remove starter - 3 bolts all I think 6 or 8mm allen heads.. one is easy, two are a bit more tricky. judicious use of an extension bar and a slim 3/8 drive allen may be useful (one bolt is behind a 17mm nut which holds a plastic cable/pipe tray above gearbox) - just move starter out of way, dont think you need to take electrics off -
then that will allow access to hole in the engine block which engages with a hole in flywheel and a ?8mm drill bit, bolt etc will slide in - when turning engine over by hand*..

then when that is in, see if the two holes in inj sprocket align with corresponding threads

and check the cam sprocket hole lines up with the 8mm thread in head..

if all do, then all is well on that front..

*(turn engine clockwise from crank sprocket, it may be worth popping offside front off the ground and wheel off and also wheel arch liner)

ok so maybe an hour all told.. but if all belt timing proves ok then that's a weight off your mind..

Unread post by **Peter.N.** » 04 Sep 2010, 10:03

You can gain access to the hole behind the starter with a suitably bent wire coat hanger, the thicker type is to be preferred, bend it into the shape of a starting handle (for those who remember them) and you can slide it along the back of the starter and find the hole with not to much difficulty.

Peter

MikeT · Unread post by **MikeT** » 04 Sep 2010, 10:46

shaunlfc1 wrote:I am not sure but we did have a page up on screen that showed coolant temparature to be 20 degree's and it also showed "counter 40".

No, that was not the Live Parameters page but can I assume that 20 degrees was read from a stone cold engine? If it's a recorded fault you might have a failed coolant sensor.

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 12:29

The car was started from cold and ran for about 2-3 minutes whilst Tony had Lexia connected to it.

The car has not been run or started for over two weeks before yesterday afternoon.

I thought 20degrees' seemed reasonable as the sun had been on the car all day and it was about 19-21 degrees here yesterday.

Would the live parameters page given us more information then? Perhaps another session is needed?

The coolant temparature sensor is the only one I have not changed as GSF could not source the correct one for me, and I've not had the time to get one from Citroen!

Thanks again for your help, I await further great advice!

Shaun

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 13:27

Coolant Sensor UPDATE:

Managed to get down the Auto-factors before 1pm to get a new coolant sensor.

Installed and..............................................................................................................................................No joy still! K-light on, still got me horrible noise.

So I would say we can definitely cross that sensor off the list!

Surely now it can only be timing or fuel pressure, but my see-thru fuel line show's no sign of bubbles and I would of thought if the bosch pump was not getting the right pressure of fuel it would run like a dog?

Mine runs fine doesnt miss a beat apart from the horrible extra loud diesel knock. I would expect to run very intermittent if it was getting irregular or poor fuel pressure, maybe i'm wrong?

The sage continues.......

Cheers.....

MikeT · Unread post by **MikeT** » 04 Sep 2010, 15:49

Hi Shaun, I suggested testing the sensor before recommending replacement but never mind, it's done now. At £15, it's worth the peace of mind as they do tend to fail from time to mine - mine did and the ECU followed it by retarding timing when it wasn't necessary. Just to be sure, there are two coolant temperature sensors, one blue and one green - which did you replace?

The Live Parameters page shows, among other values, what timing the ECU is asking for and what timing the pump is delivering. I suspect you'll see the ECU asking for more advance than the lift sensor is reporting so the cambelt timing is a major suspect.

In reference to fuel pressure, the pump pulls it from the tank then pressurises it for injection. If there's a fuel restriction, it won't really be evident until high demand (high rpm) where the pressure drop will cause a retard of the timing so if you're getting horrible noises at all revs and it otherwise drives fine, I can't see it being a pressure related problem personally.

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 15:56

Thats great advice thanks.

Unfortunately now I dont have acces to the Lexia, the parameter page sounds like it would of defintely told me whether it is a timing problem then?

I changed the green sensor.

Surely though if the timing was out as in the belt has jumped one tooth it can only retard the timing not advance it!?

Unfortunately I am not going to be able to check the timing until I am back from holiday a week monday!

Cheers again,

Shaun

MikeT · Unread post by **MikeT** » 04 Sep 2010, 16:07

I can't be certain but I would have thought it depends which way the belt could have jumped? For example, if it jumped so the static timing was too retarded, the pump cannot physically give full advance, even thought the solenoid was getting the right signal and vice versa.

Unread post by **Peter.N.** » 04 Sep 2010, 16:09

Hi Shaun

Retarding the timing would be the obvious scenario for a slipped belt, but as it sounds advanced and you can't find any other reason its certainly worth a look.

I don't know how much control the injector with the sensor exercises over the timing - but I think we have already been there.

Have a nice holiday.

Peter

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 16:28

Once I am back from me hols I'll set about checking the timing, and if that still doesnt show any issues, I will do what my colleagues have suggested and simply retard the fuel pump timing until the noise goes away but this has risks that she my be a bit more thirstier or not run quite as sweet.

Would you recommend another Lexia session?

Cheers again peeps....

Shaun

Unread post by **Peter.N.** » 04 Sep 2010, 16:43

Hi Shaun

If you set the timing to where it sounds and runs right, it will be right, the performance will only be affected if it is to retarded, this will make it difficult to start and very quiet. The only problem will be if the auto advance on the pump is not working, but you will discover that when you try it.

Peter

Having thought about what I just said, I suppose its not possible for the pump to stick in the fully advanced mode, that's what its in a lot of the time you are driving it.

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 16:51

Well I know the pump timing has not moved and is where it should be as there is a white paint line on the pump and mounting flange and this has not moved or been broken, so the pump is timed right, so it can only be the cambelt that has moved surely?