New inlet manifold = much better MPG!

[124coupe]

My late 06 E280CDI Estate (56k miles) went into limp mode on the M42 and the Mobilo guy diagnosed a failed "flap" motor in the inlet manifold (symptoms max 30mph and no warning lights!).

Two days in a loaner CLK 220 diesel (yuk! - not a patch on my 95 320E coupe) and it came back with a whole new inlet manifold which, in the words of the service guy, is a real stinker of a job...

Anyway, long-term average MPG up to the failure was 34.5 - I would usually see 35-36 ish for a fast motorway trip and 28-30 tootling locally.


Since the repair, I get 40-43MPG average on every fast motorway trip (checked for accuracy brim to brim) and the cumulative average over the last 2100 miles is 39.7 (including lots of jams). Roll-on pick up in 6th and 7th is hugely improved and if anything I'm travelling and accelerating faster.

The gearchange is also much smoother and has lost the feeling of flaring on gentle acceleration up-changes. Also, now you can't feel when it "drops" 7th to 6th when you press on from 60/70mph.

I wonder if the old manifold flap was always faulty or sticky?

 

[Blobcat]

Interesting, I bet that was fun on the M42, we're you in the restricted area at the time?

I get ~42Mpg from motorway runs from my Dec 06 E320CDI so yours was not at all happy :-(

 

[124coupe]

Yes, the restricted bit so i tootled off on the A41 and into the layby.

 

[colechelle]

just to put you right you have a new inport shut off motor, done 3 this week a lone!!!!!!

 

[Xtractorfan]

And i know of two E220 cdis that have had them fitted recently..but never seen the fault mentioned on here before..

 

[124coupe]

Might well be the inport shutoff motor that died but they fitted a whole new manifold - the service guy waved the old one at me when I picked the car up.