2007 E280 cdi lack of power

[StevieB69]

Hi all, 1st time poster so please be gentle
My beloved 2007 E280 cdi estate (105k miles) has developed a problem and I wonder if you guys can shed some light.
Basically the engine is dropping into limp home mode. This seems as if it might be temperature related as it is nearly always ok 1st thing or after several hours switched of. The time period before it drops into limp mode can be anything between 1 mile and 50 miles.
I loaned a friend's code reader and it is consistently showing "P0244 Boost pressure Valve A faulty signal" with a very occasional "P0132 Lambda probe bank 1 signal too high".
Having read loads of excellent posts on this site I saw that sometimes the P0244 is associated with the infamous port shut off problem so I have tried the 4.7k resistor bypass on both this and the EGR but neither have had any effect. One final observation, the turbo actuator stops moving when the engine drops into limp but I guess this is supposed to happen as part of the limp management.
Thanks for any help you can offer

 

[BlackC55]

http://www.mbclub.co.uk/forums/engine/144927-lack-power-cdi-what-do.html

 

[StevieB69]

Thanks BlackC55,
I'd already seen your excelent post and I'll answer as best I can,
I've checked all fluid levels are ok and checked a few under bonnet fuses that I've seen mentioned in other posts. I haven't checked them all as I was worried that pulling random fuses may upset something else. I've had a good listen and I can't detect any unusual induction noise but I have been listening to Motorhead for 30 years! I don't have the code reader with me so I can't give the precise figures but it does have a live data feed and if I remember correctly the MAF reading was the same when running correctly or when in limp mode. I'm not necessarily looking to sort this myself (unless it's an easy fix), just after some good solid info so I know when I'm being led up the garden path. Does anyone know of a decent indie in the Stoke-on-Trent area that could tackle this?
Cheers

 

[StevieB69]

Quick update. Been to the local indie (MERX in Fenton S-o-T) this morning to get a STAR diag done. Showing 2 faults that appear to be the same as the ones previously described all be it with different codes, turbo regulator & lambda sensor. So the turbo one is 2510-001 - Check component Y77/1 (Boost pressure regulator). MERX suggest remove turbo and send away for actuator repair which will take a week. If that doesn't fix it then it's the port shut off motor. I did try the port shut off bypass with a 4.7k resistor but it didn't make a difference but now I'm doubting myself and wondering if maybe I didn't get a good contact or something. Anyone got any thoughts?

 

[E270 Owner]

Remove the turbo actuator and open it up,
you will see a broken wire in there from the pcb to the outer casing,
re-solder it and it will work again.

Make sure you lubricate the moving parts sparingly.












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[StevieB69]

Thanks E270 Owner, I have seen similar things elsewhere and considered having a look at the weekend. You mention lubricating the drive mech, are you talking about the external linkage or the internal gear mech? Have you any info on what to use, oil, grease, WD etc?
Thanks for taking the time to reply, much appreciated.

 

[E270 Owner]

Small blob of white grease on the plastic cogs.

Lube up the externals with high temp copper grease.

Inspect the worm gear for damage.












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[StevieB69]

So, yesterday I took the plunge and removed the actuator from the turbo. Technically this can be done by removing 1 circlip and two 10mm bolts but I was worried about dropping something so I removed the turbo heat shield and a bracket to improve access. Once I'd got the actuator open on the bench it was exactly as E270 Owner said, a broken wire! It wasn't immediately obvious but a light prod with a flat blade revealed the broken connection.

A word of caution for anyone wanting to attempt this repair. These link wires are very fine and VERY fragile. After several failed attempts I called on the services of a friend with a pro 65w solder station. After an hour of head scratching and much cursing he eventually got a joint that he deemed "acceptable but no guarantee how long it will last". The solder just seems to roll off the pads and won't stick, if anyone has any suggestions or experience I'm sure you will help someone in the future.
Again took E270 Owners advice and lubed the internal worm gear sparingly with white silicon grease (couple of quid of ebay). Reassembled and back on the car in 45 minutes and time for a test! 30 miles later one very happy E280 owner can't thank E270 Owner enough
Been out again today for a tootle round the Peak District and clocked up another 60 odd miles without fault so I'm beginning to believe it might be fixed
I'll post an update in a week or so but in the mean time I hope this helps someone else keep their hard earned in their own pocket.

 

[E270 Owner]

If does break again use this stuff

Wire Glue ~ Original Electrically Conductive Glue Adhesive ~ No Soldering Iron ~ | eBay

Personally I very carefully Dremmel back to the copper base on the pcb and casing joint so it takes the solder easier.












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[StevieB69]

Quick update, it's been a month now and happy to report that E270_Owner's fix was spot on and normal service has been resumed