w220cdi whitish smoke in the morning?? Why??

[haydar]

Hi all

I've got a w211 220cdi 2002. When the car is started first thing in the morning, the car gives off whitish smoke. It smells like unburnt diesel and it's definitely not water vapour. The idle is very slightly erratic, as if the car is missing every now and then, but it's not major. Now here is the interesting part. If I leave the car idling, it will continue to give off this white smoke. If I dive it straight away, even for only 1 mile, the while smoke totally disappears and will not be seen again for the rest of the day!

I'm based in Pakistan where the diesel has high sulphur content and hence I had to have the catalysts removed, but I think it was puffing white smoke even before this.

I've had the injectors changed and also the valve stems, but neither has cured this problem. I've also had all the hydraulic elements changed, due to it being a noisy engine. The compression test on the engine shows all cylinders have good and almost exactly the compression.

Now some other issues that might be related. The engine is noisy, even for a 220cdi. Sometimes when the car is cold and I select D from P, there is a load clapping noise that comes from the engine for a second or two??? The car is very, very fast! I kid you not, it is an auto, yet still wheel spins away from lights. When I had it on the STAR diagnostic tool, the torque figures that the car was producing were very high. So much so in fact that the technician was not able to perform the gearbox adaptation since the torque figures would never fall within the required figures!

Now for my questions:-

i. What could be causing the white smoke in the mornings and what would be the test to verify this? I'm thinking that possibly an air leak??

ii. What could be causing the load clapping noise from the engine?? Could it be the timing chain? I just can't think of something that could make this type of noise, but then stop and not continue??

iii. Why does the car have so much torque?? Could it have been chipped? If so how could I find out?

All help greatly appreciated.

PS. The car has covered roughly 110,000 miles.

 

[MBManInKen]

gives off whitish smoke.

Habemus Papam!



Sorry, couldn't resist - apologies for failing to provide a proper answer .

Dieselman or someone else with the right knowledge should be along shortly to help you out though .

 

[Dieselman]

Hi haydar.
At a guess the white smoke and noise might be timing being too far advanced or an injector injecting too much fuel.

Firstly have the injector leak-off and flow rates checked, then have the fuel rail pressure checked and the actual injection timing dynamically checked.


Are you sure the white smoke isn't just condensation being emitted, if so it could either be normal depending on overnight temperatures or the head gasket could be weeping water into one cylinder. Check the water in the header tank for level and any oil.

If you have the ECU software version read it should be a proper MB version. If not maybe hte car has been remapped.

Has the car always done this or is this a recent change?

 

[MBManInKen]

Hi haydar.

See, told you so!

 

[c240yaz]

White smoke in most cases means unburnt fuel. Several possible causes as Dieselman suggests. Sometimes a pump timing / calibration problem.

Occasionally, it can be water in the system, ussually head gasket, seapage between water channel and clinder bore, creating steam, but as you mention dissapears after warm up, this is unlikely.

By your description, sounds that something minor is wrong.

 

[haydar]

MBManInKen, thanks for your moral support

DieselMan, what would be the cause of injector leak-off or incorrect flow rates. (It might be simpler just to change he part than diagnosis????)

The spoke is definately not condensation.

Good idea regarding checking ECU software version, that might highlight why the car is producing so much power.

 

[robert.saunders]

Habemus Papam!

I thought that was the genie from Aladdin

 

[MBManInKen]

I thought that was the genie from Aladdin

The pope came out of Aladdin's lamp??

 

[Dieselman]

DieselMan, what would be the cause of injector leak-off or incorrect flow rates. (It might be simpler just to change he part than diagnosis????)

Worn injectors will leak too much diesel back to the fuel tank, which normally manifests itself as poor starting due to air leakage.
Have the flow rate and spray pattern checked just to see if they are ok.

The noise and extra power are what make me think of the timing being too advanced.

 

[Dieselman]

Sometimes a pump timing / calibration problem.

Interesting that this is a CDi so no mechanical timing setup. That's not to say it couldn't be out though, especially if the ECU has had a dodgy remap.

Needs checking dynamically.

Just thinking, I wonder if the CKP (crank sensor) could be faulty so causing the timing to advance..

 

[haydar]

Dieselman, thanks for the info. Will check the CKP, but doesn't that generally lead to starting problems? My car starts straight away. However there is one strange thing. When the car is started , the engine note is beautiful, however after about 2 seconds the engine note hardens and the car get's noisier.

Do you have any idea what could be causing the loud clapping noise from the engine when I go from P to D? It only does it when the car is first started in the morning for a few seconds and then stops??? What is there in the engine that can cause this? Or is it just a case of very bad diesel knock?

 

[c240yaz]

The pope came out of Aladdin's lamp??

No, It was Mohamad that came out of the lamp.