OwnerOfCLK430

Hello guys.
I am the proud owner of a CLK 430 1998 model, but lately I have been having some engine trouble
When i start up on cold engine, and start to drive away slow there is no problem. But, when i give about 30-40% on the throttle the engine starts to "cough" and it feels like it misfires on a few cylinders. Kinda feels like it doesn't get the right fuel/air mixture???
When the engine is nice and warm the problem fades away, but it has happened a few times on warm engine as well. But it never happens over 4000 rpm, it sometimes cough its way from 3500-4000 but when it hits 4000 it feels like big kick and it revs up like never before
I think it might be the mass airflow sensor, or am I completely off?

Thanks for any comments in advance, and sorry if my English is off
#Norwegian

cindyclk

Has it thrown any error codes?
It sounds like a bad MAF or CPS but the code readings should tell.

OwnerOfCLK430

Thanks cindyclk for reply

yes i thought maybe it was the MAF, and yes I got the yellow cheack engine light one time. The engine was cold and i gave it to much throttle and then the check enginge light came on, drove for like 30 minutes and parked the car. Next time i started up the light was gone :S

MarcusF

+1 on the MAF guess. If so, it's an easy job and the part isn't expensive. Here's a DIY

OwnerOfCLK430

Thanks for the guide MarcusF, i will try to clean it i think since they are extremely expensive here i Norway. Cost like 500 - 800$

OwnerOfCLK430

Do you think this will fit? and do you think it is genuine part?

http://www.ebay.co.uk/itm/AIR-MASS-S...item2c73a0860a

Serndipity

Typically Mass Air Flow sensors slowly fail. Basically, the electrical signal it sends to the engine management system, moves out of normal operating range, which affects the fuel/air mixture. Often the cause is that, over time, the sensor element picks up dirt/grime, which alters it's ability to operate properly.

Initially, when slightly out of range, the engine may begin to hesitate, run rough etc., and even throw a intermittent CEL. If the operating condition continues, you should get a persistent CEL and then be able to obtain a specific error code.

Of course, there could be other reasons for the symptoms you describe (e.g. restricted air filter, air/vacuum leaks etc.).

Here in the USA, an entire OEM MAF assembly (e.g. body and sensor), from reputable suppliers, costs about $150. The DIY replacement only requires a screw driver and 10 minutes time.

BTW, some of the suppliers even can supply just the sensor, at a much lower price.

The MAF sensor element is fastened to the body with (2) torx screws (e.g. remove the electrical connector, the (2) screws and pull the sensor out).

Another reason I mention the sensor being removable, is that you may have read that cleaning the MAF has had mixed results. IMHO this is because the sensor element was not properly cleaned (e.g. just spraying cleaner into the MAF body will not work well). CRC produces a no residue MAF cleaner that can be used to properly clean the sensor element.

Lastly, after a persistent CEL due to a MAF fault, upon repair, the CEL will turn off after (3) cold engine starts.

OwnerOfCLK430

Thank you very much Serndipity for reply.
I took the cost and bought my self a new MAF, new air filters, new fuel filter and spark plugs. I am away at work, so I will have it ready in about14 days. I will let you guys know how it turns out :-)

OwnerOfCLK430

Thanks all for reply. I forgot to update how it went. I canged the MAF and the car now runds smooth as ever
Thanks again.

aylanz

look like my car problem b4... But also settle r ready