1997 C200 Elegance (Erratic Idle)

[jgibb]

Hi There,
I have a 1997 Merc C200 Auto 106,00mls serviced at service times had it for 4years no problems up until now.In the morning when cold it starts of the key then stops then when I start it again it idles erratic then after a few minutes it settles, on the motorway it runs fine no problems, today when I used the kickdown it gave a sound like a backfire which could be heard within the engine area can you help.

 

[melgonzo]

Hello,
I have the exact same erratic idle and a pop or backfire sound on a 1995 Merc C280.
When put in drive idles down and when reved on highway a pop or backfire sound comes from engine .
I have cleaned MAF and the whole air compartment to the intake also replaced overvoltage relay about 6 months ago.
I am wondering if you solved your problem or have any advice .
Thank You.

 

[Ellsy Tanners]

I think a replacement maf may be required, cleaning is not always successful.

 

[melgonzo]

Also I forgot to add that some of the time I can put the gear in neutral switch off the engine then restart engine and engine runs smooth.
Is this something you have had heard of have had happened in the past.
Thank you for your reply.

 

[MB TECH WARRINGTON]

Also I forgot to add that some of the time I can put the gear in neutral switch off the engine then restart engine and engine runs smooth.
Is this something you have had heard of have had happened in the past.
Thank you for your reply.

sounds to me like air mass/maf is faulty

 

[television]

As Ellsy and MB tech got to be the MAF and they do not clean very well as the sensor goes out of spec. Most cars run to test with it unplugged