C180K hunting

[Daviebandit]

Hi all,

This problem started only today, was driving along then stopped at roundabout the revs dropped to about 400rpm and started to jump up to about 900 and back again. got to work and started the car tonight,started fine then after about 2 minutes started to play up again. very annoying fault when in traffic any ideas anyone before i take to the dealers. (2005 c180 petrol)

Cheers.

 

[Ellsy Tanners]

I would say that the crankcase breather hose has split, this allows un-metered air into the engine giving the symptoms as you describe.

Its not a easy job i am afraid for a diy. So A trip to the dealer maybe required.

 

[Daviebandit]

Hi i got a loan of a fault code reader and it gave me the code P0171
System Too Lean (Bank 1), does this sound correct car is booked in at dealers on friday

 

[power-steering]

You've got an air leak on the system.. if un-metered air is allowed to enter the engines' combustion chambers.. then it's leaning out the fuel mixture which will cause that fault code.

Check all the pipes like mentioned above crankcase breather hose and others..

Good luck mate.

 

[television]

Hunting on a petrol engine is 99% an air leak fault.

At idle the vacuum is at the highest, the engine sucks in air and speed up, the vacuum goes down, and the engine returns to idle, and so the cycle repeats itself, it does not do it when cold as its on full fuel enrichment.

http://www.detali.ru/cat/oem_mb2.as...624716.633&CT=F&cat=69V&SID=80&SGR=010&SGN=01

A pipe off or lose is all it takes

 

[Ellsy Tanners]

The fault will be the hose I described in the first post with that fault code.

 

[Ellsy Tanners]

It is 122 in this link


http://www.detali.ru/cat/oem_mb2.as...605716.628&CT=M&cat=63A&SID=01&SGR=015&SGN=03

 

[Daviebandit]

hi thanks for the replies, can hear a noise from the direction of the hose you described, had a look and think i will leave it to the dealer to repair so many thanks guys.

 

[Daviebandit]

hi again,

Thanks Ellsy you were spot on,it was the hose you mentioned. said to the dealer what i thought it was and they confirmed it an hour later, car now repaired and running smooth again.its guys like yourselves that make these forums work,,again many thanks.