not rev above 3k, limp mode?

[c220cdi2010]

and takes an age to get there as well

Hello All,
Hoping quick and easy advise lead to even cheaper fix

no lights on dash to indicate an issue.
not been able to scan it as yet; after pointers really; will scan in daytime tomorrow.

Due B5 service in 85days
mileage is 98200

cruises just fine, just not able to rev at all and acceleration is fun off some roundabouts as no go at all; defo not trust it with missus and kids in it.

I am assuming limp mode and if so, how do I cheaply and easily fix if possible.

car is a c220 cdi june 2010 blue efficiency estate
only ever filled with esso supreme
half a tank at present left

have noticed a few times over course of time that the engine temp gauge can get to 80 and then rise slowly before drop to 80 and then settle at 90 - never noticed any issues ever when has done this.

Thank you.

 

[CabrioDave]

Yes, this sounds like "limp home mode".

First, have you done the obvious: pull over, turn off, give it a minute and start again.

I've had the occasional limp-home mode activation, which could usually be fixed that way, for anything up to a year before it happened again!

 

[bob6600]

Yes it's limping and will not always put on a dash light but should throw up a fault code.

You need to get the codes read to determine what the cause is, otherwise you will be peeing in the wind. It could be engine or gearbox related.

 

[c220cdi2010]

thanks bob, had feeling codes would be needed.
defo 1st job of morning then.

Thanks

 

[Furno]

I've had cars in limp mode before (both electrical and mechanical) and they've never been as sluggish as you describe - although they get stuck in a gear (or 2) they tend to operate fairly normally in that gear.

The sort of symptoms you describe sound more like a blocked or dying catalytic converter.

Just a thought.

 

[m2287]

Throttle position sensor?

 

[c220cdi2010]

morning all,
well did a scan using the android torque app and get:
p2279 - powertrain
intake air system leak

tried a clear and came straight back.

furno, maybe i over did description. she is ok until 2.5k and then struggles to hit 3k. once at 3k, no more movement.

m2287; how would i know or check this?

 

[bob6600]

Torque is very basic but going by the generic code, I would check all hoses for a boost leak.

 

[c220cdi2010]

Thanks bob.
would like star but stealer will be a few more kidneys than i have!

unless anyone is near shrewsbury, sy1, and wants a beer token will be all i have to go on

 

[jpwilliams]

Had same problem with my Eclass.It needed a new MAF.
rEGARDS
jOHN

 

[bob6600]

Look through BlackC55's sticky and go from there.

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

 

[c220cdi2010]

well, just done what can with a can of deodorant sprayed around joints where i can and no change in engine revs to indicate a leak of it being sucked in.

read that and looks like trip to garage to star and see whats up

this:
It is always worth doing a manual check with the live data just to be sure that is the cause.
How do i know what is right and wrong data?

neil

 

[m2287]

If it's the throttle position sensor the only way the check is to swap the throttle pedal with one which you know works, it does not come up with any fault code as far as I know.

 

[c220cdi2010]

so could be, maf or throttle sensor or pipe leak
cool, small things to start with so think will book with mb tech

case of need fixing and i have limited skills and knowledge

thanks all.
will update if a clear fix is known

 

[BlackC55]

Look at my sticky in the engine section

 

[c220cdi2010]

had a read from link given by bob further up, and feel needs garage to look at properly.
skills, time & knowledge thing

Neil

 

[c220cdi2010]

just realised that when was working at x revs (think was 1800) it would tell me to change gear & now no longer does

point towards throttle position sensor?

Neil

 

[BlackC55]

It doesn't have one so no!

 

[c220cdi2010]

ok, thank you.
it was offered as a suggestion and assumed would be linked.

Any other reason why the 'tell me to change gear' feature would vanish when in limp mode?

 

[CabrioDave]

ok, thank you.
it was offered as a suggestion and assumed would be linked.

Any other reason why the 'tell me to change gear' feature would vanish when in limp mode?

Remember that what has gone wrong is not directly causing the set of symptoms you have. Those symptoms are what it's like in limp home mode, but many different causes can trigger the car's management systems to switch to that mode. The mode is intended to allow the vehicle to continue, but in a way that won't cause the engine to damage itself.

When in that mode, the engine won't have the same power or torque that it usually would, so won't be able to accept the next gear at the usual revs. It seems likely that the designers will have ensured that when it switches to limp-home, it stops signalling the gear change.

Incidentally, the symptoms you quote are exactly what I used to get, intermittently (on a Sprinter, as it happens). The dealer, and a tame specialist, came up with many things which could have triggered it (codes showed the mode activated, but not why). When, after 3 years, it became more frequent, they finally tracked it down to the turbo pressure sensor. The same symptoms could occur with other faults, though.