mleskovar

Right on

TruTaing

By no means am I a mechanic. This is why I ask the questions that I ask And I am not going to rush off and buy new sensors for the thing either. I am here for the valuable input that you guys have given... I wish I was better with cars, but this is my first car and I AM making an effor to learn more about my car. Today I have learned about Suspension (reading a couple random threads about suspension and reading some stuff around the web) and I have learned about fuel trim...

Buellwinkle, I will try those things that you described above.. but once again I am definately NOT a mechanic, and I do not have many tools. What would I need to perform some of these checks?

TruTaing

mleskovar,

My filter was in pretty clogged up (somehow.. lots of small leaves got in there). I think thats why my mpg improved. I do mostly city driving and i would imagine that i would get around 24+ mpg all the time, but you are gettin 26! I am very jealous. Do you have any mods to that thing that help fuel mileage?

mleskovar

No mods, I rely on the expertise of the engineers that designed the car. When I was younger it was fun to mod but now I'm an old fart and realize they know more than I think I know or will ever know. If I want to go faster I buy a faster car. MPG is a function of the car being properly maintained, environment, and driving habits. My environment lets me average 35 mph, what's your average mph (go to the second screen for cumulative)?

TruTaing

My avg mph is 48.4. Although I am stuck in traffic often and at a dead stop.

Buellwinkle

Trutaing,

The best thing for a novice, one that's computer savy and has a laptop is to get OBD2 software and a cable so you can view codes, reset codes, view sensor output, log sensors while you drive for later review. Save a log of every sensor when your car is running fine so you have something to compare to when it's not. This will tell you a lot. The next thing be able to do is read spark plugs, take them out and look at the color of the electrode and compare it to charts available on the net. Doesn't cost anything other than a spark plug socket to remove them. Next that's important yet cheap is a multi-meter to check the battery, charging, sensors. Lastly, for the DIY person is a fuel pressure gauge as many misfires are caused by low fuel pressure. As your car gets older you may need a compression gauge. A scope would really help to diagnose electronic problems with the ignition and injector electronics but they can be very expensive, thousands.

mleskovar

That's very high, you do more highway cruising than you think. I'm surprised your mpg isn't higher but it's not abnormaly low. When I take 800 mile round trips to Arizona I usually average 28.5 mpg....over 30 mpg when I don't exceed the speed limit

TruTaing

The light came back on this morning....... I didnt think that resetting it was going to solve the problem. I was kind of dissappointed that a simple reset would get the light to go away and that i didnt get to really approach/solve the problem. Hey, well now ive got the opprotunity to try some of the stuff you guys are talkin about... Updates to come.

thanks again.

C240-Merc

mleskovar, I bet you can help me then. This problem has happened to me twice since this past Saturday. I filled up with 89 octane gas on Saturday . I drove the my 2001 c240 approx. 30 miles to a store and when I came back to turn the car on it wouldn't start. For lack of better words, it would make a putt putt putt sound when I would turn the the key. I tried several times, probably 6 -10 times when it the engine finally turned over (this is after I popped the hood and removed the airfilter above the battery b/c I thought the problem was the battery). After the car turned on the "check engine" light came on until I turned the car off. 30 minutes later when i started the car everything was normal. The car has acted normal since then until this afternoon-the same thing happened again with the "check engine" light and everything. (the reserve fuel light just came on) I am thinking it was the type of gas that I put in the tank. Has anyone else had this problem? What does it sound like the problem is?

mleskovar

Putt putt sound?? Was the engine turning over but not firing or sound like it was firing on one or two cylinders only? Could be bad gas, like water in the gas. Did the car run rough when it started and have less power? A quick check for water in the gas is to hold your hand at the exhaust pipe outlet while the engine is idling and see if it collects moisture, or is water dripping from the exhaust? The CEL could be from the gas cap not sealing properly....look at the rubber gasket on the cap where it supposed to seal against the filler pipe. Also...did you keep clicking the gas nozzle to make sure it was filled completely (bad thing to do as you can fill the charcoal canaster with gas)? Did the nozzle shut off without spilling gas? The CEL codes should be stored in memory so have it checked.

C240-Merc

It happened again!
The engine sounded like it wanted to turn over, but it wouldn't start. I was just at the car wash and it happened again, however the car will eventually turn on after what seems to be the 20th time that I try to start the car. After the engine is running everything is normal again, with the exception of the CEL being on. I will run a check tomorrow morning. Do you think a place like auto zone will be able to do it for me or should I go to the dealer?

mleskovar

OBDII check might give you more questions than answers but it's free at Autozone and you can write down the code and get it cleared so in case it happens again you'll at least have history. The dealer should be more able to pinpoint the problem and give you an idea of what it will cost.

C240-Merc

Thank you

StapleGun

Just for your 411, P0170 and P0173 were fuel trim, left and right banks, respectively on my vehicle - it led to a MAF replacement (Mass air flow sensor) that cured my CEL woes for once and for all. Your hesitant starting problems might be a Crank Position Sensor about to go on you, both common problems on MB's, as of late. Invest in the OBDII scanner and quit being penny-wise and dollar foolish, they're cheap and will save you the headaches of driving around incessantly to the $tealer$hip and others pleading for them to use their scanner.

TruTaing

Ah, im gonna go it the buellwinkle way. Or try at least. I have finally purchased a little cord to connect my computer to the obdII port and found some software to go with the cord. Hopefully ill be able to see whats goin on.... Buellwinkle, you are a MB forums super star. I just signed up on mbklasse and i see you are on there too esp on the DIY section. I might PM you later buellwinkle... might need some other little details about this and that... thanks a bunch.

Thanks for the suggestions fellas...

Ill update you guys about what happens and what i find.

b3d_sage

funny, I JUST (like a few minutes ago) found out the same thing was wrong with my C320.

TruTaing

Well, lotsa peeps seem to be having problems w/ that MAF. How does one know that it is malfunctioning? (I have even seen a note next to p0170 to check vacum leaks and the MAF) without going to talk to the dealership of course...

Is there a way to 'clean it' or repair it w/o actually replacing it? its an expensive part... everyone says its like 300 bux :x

thanks!

Buellwinkle

You can sometimes find the MAF on ebay for about half the price of the dealers which is around $350. The dealers charge a few hundred to replace it but it's really only a 20 minute job and you barely get your hands dirty doing it. Of course once replaced you need the OBD2 software or scanner to reset the code. Keep in mind that federal clean air act provides for an 80K miles emmissions related warranty on each and every car that the dealer has to honor or be fined, even if it's your fault that the sensor broke because of a mod. While it's educational to troubleshoot it yourself, no need to spend $350 replacing a part that the dealer will replace for free.

TruTaing

I have never heard of this 80k miles emmissions waranty. Could you elaborate some more on it? simple googling says its 5 years or 80k miles. I bought my car used and it is an car is an 2001 model and i havent reached 80k miles. I didnt buy it from a dealership, but is there a chance of gettin the MAF replaced for free if i drop into the local MB dealership?

thanks again buellwinkle

b3d_sage

diagnosis, though, can be time-consuming. right? I just spent ~700.

TruTaing

:\ that hurts. what was the hourly pay? 175 an hour? for 4 hours?

Question: what does it mean to have fuel trim in the right/left banks? or is it first/second?

thanks,

b3d_sage

it was diagnosis, parts, installation

Buellwinkle

This is not an MB thing, it's a government mandate, 8 years, 80K miles - http://www.epa.gov/otaq/consumer/warr95fs.txt

C240-Merc

Has anyone ever presented this (the EPA Environmental Fact Sheet) to a Service Advisor? My check engine light came back on a couple of days ago. The Autozone scanner says that it is code P2017"Self Adaptationof mizture formation from bank 1/2 of cylinder is at max./min. at idle speed." I am going to the dealer first thing in the morning to run it on their scanner.

TruTaing

I gave in and just had my car looked at today by a tech...

He gave me error codes of p0170 and p0173

Ssaid that the voltage accross my MAF was 1.1 where the recommended was between .98 and 1.03. That cost me "one hour of labor" which is 80 bux

He is trying to charge me 388 dollars for the MAF and half an hours service to install it.

I can find the MAF on ebay (link below) for 175 + 18 dollars shipping

http://cgi.ebay.com/ebaymotors/Merce...QQcmdZViewItem

and installing the MAF consits of only a few steps:

Remove the airbox, unclip the little bracket for the MAF, unplug the MAF, and pull it out. put in the new one, put everything where it was and you are good!

As for clearing the light. Ive got a little obdII scanner that can do that for me.

Thanks to everyone who commented and gave me suggestions. I wish i could have taken a more DIY approach to solving this problem, but I dont think i was quiet qualified to figure out exactly what was wrong with my car. I dont know where i could have found the ideal operating voltages for my MAF either. If i had known these things, i think it would have made it easier to determine exactly what was wrong with my car. I know it was suggested (buellwinkle) that i get a multimeter and read the voltages, but its difficult to know what voltages are proper.

thanks again,