807 2.0 HDI, 100kW - turbo whistle

[kurnt29]

807 equiped with 2.0 HDI, 100kW engine and disturbingly loud turbo whistle.

It seems to run OK when cold. Loads of power and acceptable turbo noise.
But as engine gets warmer whistle becomes more and more noticable until it becomes disturbingly loud when at load (no whistle at no load). It is so loud that it seems like turbocharger was positioned between drivers knees.
Also engine performance is noticeably affected - the warmer the engine, the lower the power is.

So far checked:
1. Exhaust - no leakage.
2. Intake hose between air filter and turbo - removed, cleaned and inspected with no damage or leakage found, o-ring seal at the turbo end is OK.
3. Hose between turbo and intercooler - inspected, no damage or leakage found.
4. Intercooler - inspected, no damage or leakage found.
5. Turbocharger - no noticable play, fins not damaged (intake side), has small amount of black dust aroud VNT actuator shaft but that doesn't seem to be the origin of the problem stated above. Turbo holds pressure up to 1,3 bar at full throttle load and responds nicely to inputs (VNTs seem to be working fine) no matter what temperature engine has.

6. EGR valve - according to computer tests it is working as supposed.
7. Bolts and clamps - checked and tightened.
8. ECU - shows no errors.
9. DPF - computer shows around 30% clogged.


It all seems in good condition but turbo whistle and loss of power persist.
Any ideas where to look next are welcome.

What are usual temperatures this motors start cooling fans at (1st & 2nd speed)?

[Subsonicnat]

Not saying its the answer but, Could the oil no bet getting tot he turbo,that would account for it geting worse as it warms up,Next sound could be a rather loud screech.
{I Hope Not}. anyway just a thought, and of course it is [ invisible ].

[Peter.N.]

Could just be sightly out of balance. In our Merc c220 Cdi it sounds as though we are being chased by a police car and since I replaced the water pump the car is so much quieter that you can hear the whine echoing of the walls as you drive along. Mine also loses power when it gets hot but I don't think its anything to do with the turbo itself, rather the management system, but it still pulls well at 2000 rpm which is equivalent to about 70 mph in 6th gear, don't need to go any faster.

Back pressure from a clogged exhaust system can make the turbo work harder. Are the revs limited with the power loss? if so you could try disconnecting the exhaust and revving it to see if the problem is still there.

Peter

[kurnt29]

Could the oil no bet getting tot he turbo,that would account for it geting worse as it warms up...

But once it cools down it runs OK. If there was no oil or oil supply problem it would affect cold engine as well.

Mine also loses power when it gets hot but I don't think its anything to do with the turbo itself, rather the management system...

It doesn't need to get hot. It starts to loose power and becomes louder between 70 and 80°C, which is well under working temperature.
If it was overheating it would be normal to cut the power, but this is not the case.

Back pressure from a clogged exhaust system can make the turbo work harder. Are the revs limited with the power loss? if so you could try disconnecting the exhaust and revving it to see if the problem is still there.

Revs are not limited, no limp mode, no error, nothing - it just does not have the same power as when cold at any rev range.

[Peter.N.]

My power drops off long before it gets to normal working temperature, suddenly got no boost over 2000 rpm after about a mile or less, obviously not the same fault as mine.

Peter

[ekjdm14]

One small detail concerns me, the part where you say

"between 70 and 80°C, which is well under working temperature.

I wouldn't say it was well under working temp, would expect it to run somewhere around the 90-95c mark normally & maybe up to 105 on a hot day working hard.

What sort of temperature is the engine running at normally? (worth checking both gauge reading AND actual temperature with a cheap IR gauge on the top hose in case the CTS is giving an erroneous reading)

[kurnt29]

Been to Peugeot/Citroen specialist to talk about aforementioned problem. Went for a ride together and once I told him this car is noticeably louder than older 2.2 HDI (94kW), he smiled and replied: "Yes it is, but nothing is wrong with it. Never 2.0L cars are louder than older 2.2L 16Vs." Apparently this is due to change in air intake ducting and nothing can be done to reduce that sound.

We went for a ride in some other 2.0L 807s and they were even louder. So it seems all is OK and that this was just overreaction. Who would have thought..