Picasso Turbo Replacement (Not EGR)

[tomthered]

Right the whistling has just stopped for now which has me flummoxed. I drove 15 miles this morning and it stayed there. I was driving home down the motorway to come home tonight and it was whistling, I reached 63 mph and it just stopped. I got home and its stayed the same. However, it still has not got full power, its as though its restricted. Also there appears to be a rattling from around the centre of the black resonator or under the heat shield. Its like rattling a screw in a tin box? It still hasn't got full power though and when I was driving it seemed to "cough" under the engine a couple of times, no idea what that was. Am letting it cool then will check the turbo bearing is still intact.

It does seem to have more power than when we changed the Turbo but it is as though the power is there but restricted. Am clueless now. I will still ask Andrew to look at the black box tomorrow but will need to wait to weekend to clean the Intercooler out.

Any ideas guys and thanks for the help and guidance up to now.

EDIT:-- Turbo bearing is fine so it is not that. It still has no what I would term ooomph when the turbo should kick in when the accelerator pedal is pressed. It will build up speed gradually and has more power than before the Turbo was changed. Still unsure why its like this as it seems to have restricted power. Going up a hill it just takes time to get to the top of the hill!!!

[tomthered]

Just read on google the below, could this be the problem?

"If you disconnect the air flow meter it will cause the car to run worse.

This sounds very much like a vacuum problem. It is not uncommon for vacuum pumps to start sticking on the Xsara HDi. This will cause a lack of vacuum, which in turn causes the turbo to operate incorrectly causing a loss of power. The wastegate of these turbos is normally open, which means it requires vacuum at idle to close the wastegate, and it kills the vacuum supply at high revs to open the wastegate. This also means in the event of a problem the turbo does not overboost thereby protecting the engine.

So if your vacuum pump is producing a poor vacuum your engine ecu cannot control the turbo, which produces your symptoms. Usually giving the engine full throttle will cause the vacuum pump to start working properly (as it is driven directly of the end of the camshaft) and so you get your vacuum and therefore your boost back.

You can verify if this theory is correct by putting an abnormally high demand for vacuum on the engine and see if the vacuum pump can cope.

Whilst stationary have the engine running and pump the brake pedal until it goes hard, then keep as much pressure on the pedal as you can. The pedal should start to creep away from you as the vacuum pump builds up the vacuum pressure to the brake servo.
If the pedal doesn't creep then you have a vacuum problem.

Whilst driving try accelerating without full throttle and then braking hard. Do this a few times and see if the brake pedal gets hard or the acceleration gets sluggish. Both would be signs of loss of vacuum.

If these tests indicate a vacuum problem (do them a few times to be sure) then you can be sure that the pump is getting sticky. A new pump is easy enough to fit and will probably cost around £100 from Citroen. Alternatively try lubricating the pump by disconnecting the vacuum pipe outlet and spraying some WD40 in the outlet whilst the engine is running. This may help temporarily."

[RichardW]

I think if you had a systemic vacuum problem you would know about it, as the brakes would be awful. Possible that there is an issue with the vac supply to the turbo though? Check the pipe is attached properly. Is it still making the rattling noise? That's what ours sounded like with the failed turbo..... can you track the noise down using a stethoscope (read long screwdriver or similar pressed to your ear!)? If you undo the outlet pipe from the turbo somewhere and rev the engine can you feel a good rush of air? Failing that you need to get it on a Lexia again to see what the turbo pressures are etc.

[tomthered]

My main problem Richard is that I am partially deaf, so its very hard to hear things. Because its at the top and bottom end of the scale, which is what I need to listen to, I cannot hear it or trace the sound and where its from. I think it may have always made that rattling noise, I don't think its from the new Turbo anyway. The turbo was a complete replacement not a refurbishment and that seems OK as I have had the black side pipe of the Turbo and there is no play. My father in law used to have an old fashioned stethoscope, wish I had kept it now!!

Is the outlet pipe the one on the top of my picture where the wastegate is inside? This is the one I took off to see if the turbo bearing was OK. The big pipe has a small outlet pipe into the to of a pipe on the engine and the goes to the back of the car into another pipe?

Can you suggest anything else to look for, it does seem weird it worked fine for about 30 minutes and then restricted me with the siren noise. It definitley has more power than before but does not respond as well as it should,

[tomthered]

well it would seem the turbo isn't working according to Andrew. There does not appear to be any play in the spindle but the tinkling is coming from that. Am thinking of asking Paris Autos for a diagnosis, at least I will then know what I am looking for!!