[ckub52]

Gentlemen,
have another problem with my '2001 ML 320-Sport;,
following all the leads and procedures described within I have cleaned the MAF in my car, while the battery disconnected ALL TO MAKE the yellow warning light o go off,..... and the car was running PERFECT for about (highway) 1000 mi, then the CHECK ENGINE light came on again and the problems repeated themselves. I have recleanned the MAF, the new air filter was previously installed new, and... the engine is running very very bad.
Idle is unstable and when engine is cold the eng. stals, I've restarted the eng a number of times until I can put it in drive and go down the hill, when the engine warms up it runs perfect in higher rpm's but in low RPM's (idle to 1500) the idle is rough, not where it supposed to be. is there anything else I can fix myself and forgot about???

 

[FAR888]

Hello ckub52,

I am personally not a believer in cleaning the MAF sensor.

We have also not established what the real problem with the truck is since you erased rather than read the OBDII codes which activated the "check engine" light.

If we assume however that your MAF sensor is to blame, purchase a genuine Bosch unit from AutohausAZ and be done with it.

 

[AC_ML]

You need to get a OBD II scanner and check the engine parameters. Check the MAF sensor reading to see if it is within a valid range, and check of any other engine parameters out of range.

Check that all your hoses are connected correctly. The hose by the EGR valve is well known to cause bad idle problems when it is loose or when it pops out.

AC

 

[ckub52]

Hello ckub52,

I am personally not a believer in cleaning the MAF sensor.

We have also not established what the real problem with the truck is since you erased rather than read the OBDII codes which activated the "check engine" light.

If we assume however that your MAF sensor is to blame, purchase a genuine Bosch unit from AutohausAZ and be done with it.

Thank you for the reply, the MAF is relatively new, besides I have two ML's and have switched the MAF from one to the other, one car works PERFECT, the other does not.

 

[ckub52]

Dear AC ML, thanks for your reply, where is thee EGR? where/how will I look for the hose leaks? can you give me a hint, please?

 

[bikerider58]

do a search for the EGR valve. There is good information with at least one thread containing step by step procedures for removing and cleaning the hose with photos.

 

[ckub52]

Thanks for all your help, I did get to the EGR valve and before I dismantled it I have noticed loose connections on both ends of the metal corrugated tube connecting to the valve (?). I cleaned the tube and firmly reattached, and the idle is fine, but the car runs very slugish; up to 2000 RPM's it's OK, when I try to accelerate the engine speeds up to 3000 RPM very slowly and after awhile it kicks of as it supposed to. Any idea what causes that fenomena and how to fix that?

 

[ckub52]

I wander how my problem may releate to yours; it's 2001 ML 320 Sport-
I have very slugish acceleration problem, had that before, but not recently, the idle is fine, when I get going it's fine up o 2000 RPM's and when I want to accelerate the car just won't! the revs go up very slowly to 3000RPM, gears don't downshift and after a while suddenly it's all OK the car downshifts and start accelerating like it supposed to do. Driving in the city is a big problem.
- Just today I have cleaned some parts around the EGR valve and reatached it like it supposed to, while before I had loose screws. Anyone can give me any imput as what may have gone bad?

 

[idahombz]

read the code and you will have a better picture.

 

[ckub52]

The CHECK ENGINE light did not come on yet, any other suggestions?

 

[Brettriehl101]

The CHECK ENGINE light did not come on yet, any other suggestions?

read the codes

 

[ckub52]

Yesterday I have accessed the EGR valve, after noticing that bolts and nuts at both end of the metal tube were loose I decided to clean just that and reinstalled. The idle significantly improved, but the problem persists; when cold the engine idles smoother, after I put it in D the start is harsh and impossible to drive up the hill. after a minute I can go, slowly, and then suddenly it kicks of, downshifting the gears and moving like supposed to. What to do to make the car idle smoother and to eliminate this sluggishness when cold?

 

[ckub52]

Sorry, cn't tell from this picture where the switch is located, I too have acceleration problems and so far I have checked all, according to your suggestions, but the switch. Can you eleborate what does this switch do, and what happens if it goes bad?

 

[43sqd]

Sorry, cn't tell from this picture where the switch is located, I too have acceleration problems and so far I have checked all, according to your suggestions, but the switch. Can you eleborate what does this switch do, and what happens if it goes bad?

Please update your profile.

Click on USER CP.
Click on EDIT PROFILE.
Scroll down to ADDITIONAL INFO. And fill in the year and model of your truck and where you live.

The kick down switch is the round button device under the gas pedal. Here is an explanation of what it does.

 

[FAR888]

Have you had the truck scanned for OBDII codes as advised?

 

[ckub52]

Thanks for your reply, I have checked the switch works fine, yet I continue to have the rough acceleration problems, today; air 55 F/dry, the engine started fine, since I park on a slope it’s imperative that the car will GO!, at 1st it is choking up and instead of accellerating it seams it deccellerates, it shakes and seams that it is not running on all cylinders, after few sec it “catches on”. But it’s erratic and can’t depend on it to drive the car to town. Seams that the car runs much better when the CHECK ENGINE light comes on(?). When the eng is hot the car runs perfect. However, when I shut engine off and immediately restart it its all over again, it chokes as if it were short of breath but when it gets going it is OK. Checked the MAF, EGR and the acceleration pedal switch, all work fine. Where is the problem?

 

[43sqd]

Thanks for your reply, I have checked the switch works fine, yet I continue to have the rough acceleration problems, today; air 55 F/dry, the engine started fine, since I park on a slope it’s imperative that the car will GO!, at 1st it is choking up and instead of accellerating it seams it deccellerates, it shakes and seams that it is not running on all cylinders, after few sec it “catches on”. But it’s erratic and can’t depend on it to drive the car to town. Seams that the car runs much better when the CHECK ENGINE light comes on(?). When the eng is hot the car runs perfect. However, when I shut engine off and immediately restart it its all over again, it chokes as if it were short of breath but when it gets going it is OK. Checked the MAF, EGR and the acceleration pedal switch, all work fine. Where is the problem?

And you still didn't update your profile.

 

[ckub52]

it's not as simple as one may think, I live in the Alps and the MB S'ce is a tri away, thought I gave enough to give a clue as to what's wrong.

 

[ckub52]

I just did, will that give me long awaited and allways valued answer?

 

[FAR888]

Time to invest in a hand-held/portable OBDII scanner me thinks.

I resisted for a while but later took the plunge and purchased one.

Search the Forum for the models various members own.