chykef

please can anyone educate me on these codes P0128, P0172 and P0620???
whilst driving on highway my 04 C230 Kompressor losses speed even with foot on throttle. Wouldnot exceed 60miles/hr and slows down to 40 -30miles/hr on hills. Motor sounds like stuck in one gear and takes longer to shift gears reaching 4500rpm whilst letting out a lasting howl

MJ50

moved to W203 forum...

P0128 - coolant thermostat; bad thermostat
P0172 - system too rich (bank1); could be bad/dirty MAF sensor
P0620 - generator control circuit malfunction

chykef

Thankyou MJ50! Hopefully I'll become as proficient as you in yrs coming. I appreciate your help and armed with your advice, will visit my mechanic to see wat he says.
Now I noticed you had highlighted one of the codes as possibly "bad", is this grade in reference to cost or possibly engine issues or damage?

MJ50

how many miles on the car?
when was last time thermostat was replaced?
most likely, thermostat is bad and needs to be replaced... common repair job...

tommy

But why set the bar so low?

By "bad", he meant that the thermostat/MAF sensor could be bad and need to be replaced. Usually, people get some cleaner for that sensor and try to see if that works before swapping out the unit. But I just replaced the damn thing, under the "I don't want to be removing this silly part several times to spray it down" logic.

chykef

Please excuse the late reply to the kind words of advice. I figured i'd try the options suggested and then post the results.
The car has quite a bit of miles about 130000miles and not sure last time MAF was changed, atleast not during my ownership.
I went ahead and replaced the MAF and airfilter and tried several times utilizing the cleaner. However I'm really saddened by the fact that non of the remedies implemented has made too much of a difference. Improvement is that the car no longer "sputters" like it wants to shut off. However it definitely has lost take off speed i.e from complete stop to acceleration. i.e major reduction in torque. Plus it still takes a long time to shift gears and still lets out a loud hawl as though I have headers or them big exhaust pipes.
Rpm reaches 3500 to 4000 to go from second to third and its not manual transmission. Plus if I try to accelerate above whatever speed im and I step on gas , it starts to sputter as though dying out. Sputtering can be felt behind the steering wheel and engine seems to shake.
Please can anyone help?
Sincerely,
chyke

Moviela

Get the generator malfunction serviced. Might be an alternator regulator fault. If the battery is low, the power to fire the plugs might not be there for sudden acceleration.

Low battery can cause a raft of other problems. A misbehaving thermostat might be causing incorrect injection intervals because the engine temperature is wrong.

PelicanParts.com

If you need help doing any of the items listed here to check, you can use our DIY tech articles as a reference. Hope you get things sorted.

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