W220 S320 CDi Engine Damage??

[Voltan]

The car was 1st registered in end of Jan 2005 and had been properly maintained and moderately driven. Fuel consumption averaged 7.5l/100km or 37.7mpg. Oil used was Mobil 1 fully synthetic 5W50 without need to top-up between its 16K km oil changes.

In early May 2010 and about 65,700 miles, a Kleemann KD box was installed by an authorised agent. Even during the test drive with him the exhaust was puffing dark grey smoke and sounded “aggressive”. But I was assured by him that it was just old dust being blown away by the extra performance of the engine. Subsequently made numerous complaints of worsening dark grey smoke even on moderate acceleration, and heavy fuel consumption. He tuned down the KD Box and the smoking was less, but fuel consumption improved only slightly.

The 1st time I noticed something abnormal was 5K miles later when during a long drive I felt the car was struggling to overtake other traffic on a slight incline. Heavy dark grey smoke bellowed from the tail. Not long later a “one-half litre” top-up alert came on. I dropped speed and went to a familiar out-town MB specialist to ask him to top-up the requested one half litre. Firstly he had difficulty to twist open the oil-filler cap. When he finally did, there appeared to be an over-pressure within the rocker cover. After topping-up, he started the engine with the oil cap open. There were visible misty gas pumping out of the filler hole, which he identified as possible blow-by. From then on oil consumption was as high as 313mpl. At best I got 438mpl.

In desperation, at about 79.3K miles (or 13.6K miles after installation of the KD Box), I uninstalled the KD Box myself. The engine immediately felt smoother and quieter. There were significantly less to non existent smoke thereafter. Oil consumption improved to 574mpl (which is still horrible).

After which I went to the same Kleemann installer to inform him of my predicament. He did a compression and leak test (cost me about £92). As he could not take out the No. 5 injector, he only carried out tests on the other 5 cylinders. Result, he determined leaks via exhaust valves of Nos 2 & 4 cylinders and blow-bys in cylinders 1 & 6.

Question: WHAT DO YOU THINK IS THE REASON FOR THIS PREMATURE ENGINE FAILURE AND WHAT RECOURSE DO I HAVE? Your suggestions, however “wild” are appreciated.

P.S.: (My W211 E220 CDi of about similar age but with some 133% higher mileage, maintained by the same garage, appears NOT to burn any oil between its 15K km/ oil changes, just like my S320 CDi BEFORE installing the Kleemann KD Box.)

 

[crockers]

Ok before the box, not afterwards. Seems obvious what COULD be the cause but may not be possible to prove what WAS the cause. Suggest you ask the supplier what he's going to do?
If you can prove his box caused the problem then you may have redress. Did you get any warranty?
Tricky one.

 

[Dieselman]

You won't really know the cause until you strip the engine down, but it's possible the very high EGT have cooked the rings and valve seats.

As for recourse unless you can prove this is very likely to have been caused by the tuning box...NONE.

The best option would be to fit an EGT gauge, refit the tuning box then see if the temperatures go off the scale, if so you could prove engine damage as a result.

Let's just remind ourselves why manufacturers don't provide the maximum performance that the engines will deliver from over-fuelling.

 

[Voltan]

@ crockers : I am in the process of gathering sufficient technical opinions before talking again to the supplier cum MB specialist workshop owner.

@ Dieselman: I did question the supplier in great detail before installation, of possibilities of engine damage due to over fuelling. He assured me that extensive research were done between Kleemann and MB before public release of the KD boxes. He being a thorough-bred MB engineer convinced me that the CDi had sufficient headroom to handle the extra energy as a result of Kleemann controlled over-fuelling.

Thank you for your good suggestion on EGT test. I’d resort to that as the ultimate final resort. The car is running much better without the Kleemann for now as I am gathering information. Really don’t want to worsen damages.

After the most friendly negotiation of responsibilities, I’d have the donk stripped down to do the necessary examination followed by repairs. But for now I need your technical opinions please.

 

[rf065]

I suspect you know what caused the damage and I for one get really annoyed by all the remappers and tuning box companies who refuse to admit that engine damage is a possibility.

The warranties they offer are not worth the paper they are written on either, best option is to play nice, keep the dialogue going and hope they help you with a goodwill payment to avoid any bad publicity.

Russ

 

[Voltan]

Hi Russ, I do suspect the cause of the damage. Despite of extreme caution prior to the purchase I was swayed by the convincing technical arguments, the guarantees put forward and his credentials. But even now I am quite certain he is an honest technician and is as surprised as I with the turn of event.

Actually as his mechanics were conducting the compression and leak-test, he (the engineer/installer) said aloud that there was a possibility that that particular Kleemann was faulty and he would try out with another unit. Unfortunately due to my time constrain, it wasn’t pursued.

Your advice to keep the dialogue going is very good and I shall do that. To be fair, if need be I don’t mind to pick a portion of the bill, as I was also responsible – for believing in his sales pitch.