You were butting into a thread I was co-helping on & I have every right to disagree with your poor advice. Wake up or duck out.

 

Thanks everybody for your input, i greatly appreciate it. as far as the clogged fuel filter and sea foam is concerned...this was probably the first thing that I had tried months ago....i poured in superior fuel injector cleaner and other products along the same line in different intervals but no luck.....so i can safely rule the sea foam fix. Now based upon the codes that I got...i dont know where to begin...should i replace the thermostat and the cam sensor both and if that does not fix the problem then the next would be the cats and o2 .....? I need your guidance as to where should i begin or if there is any way of identifying a failing cam sensor....thanks once again.

 

Thanks Glyn for your input and the diagram buddy! the cam sensors appear to be easily accessible in the diagram that u provided....are they easily accessible?

 

Yeah - The cam sensors are easy once the engine cover is off. You must do the thermostat first. Then sensor. I have a feeling that once the engine is running properly at the correct temperature with no cam timing float that you will find that the emissions will drop back into range. Your Cat & O2 sensors might well have some life left in them if everything upstream is right.

 

Thanks Glyn...i will go with the thermostat first then. ..I will take a pic of the engine with the cover off and ask you to help me identify the exhaust cam sensor.

 

i just got thinkin...i have been getting the p0128 for a while now but i never noticed any problem with the car not warming up to the correct temp....it wud always operate around 80 c and heater worked fine too...any thoughts???

 

80 deg C is too cold. It should run at just on 90. The thermostat only opens at 87 deg C if it's working OK. You must get that temp up. It improves efficiency & gets the air fuel ratio correct. The car will use less gas running hotter. Running cold also accelerates wear.

 

Hey Glyn..Sorry couldnot update on the status...I have been out of town for work....I have placed the order for a new thermostat and exhaust cam sensor....i took the old exhaust sensor out and i was just wondering if there are any bench tests like resistance or something to actually verify if the sensor is bad. I know these ones are the hall effect types and have 3 pins.....is there a quick n easy test for verification. Thanks for your time.

 

thread nap for one sec. does the low refrigerant level really cause a hissing sound for a spit second when accelerating? i just noticed this earlier when i started the car and rev'ed abit. went away after a few times. my a/c is not ice cold nemore checked the a/c hoses they are good but not cold to the touch. also not the belt coz its really tight. how much to charge at the dealer? thanks!

 

I do not know how to test that sensor. Benz may have a procedure but I don't have it. Of course the dealer would just exchange it with one from his parts dept - to see if it fixes the problem. We don't have that luxury. As I said above. Experience tells me that the inlet cam sensor usually goes but that's not what the diagnostics are saying & you have been down the oil in harness road. Good luck

 

check this video out, they talk about checking the sensor...any thoughts?
http://www.youtube.com/watch?v=itMXO56z1tw

 

Do you have access to a scope to check for square wave? We don't know the Benz required amplitude of the square wave but it would tell us if the sensor is inoperative.

 

i was thinking more so in terms of how they explained..by using a test bulb while the sensor is in with the connector connected to it.

 

Can try

 

hey Glyn,
i am gonna replace the thermostat right now, any special precautions???? do i need to worry abt coolant refill n stuff. thanks

 

No special precautions - don't burn yourself! - Use Benz genuine coolant mixed 50/50 with distilled water.

 

I have a similar problem with my 1995 C280. When I shift into Drive or Reverse the car lunges forward even if I am holding the brakes. This has been happening since my misfire started... so I believe the issues are linked. I cannot find the cause of my misfire either. I have heard that a bad over voltage relay or something like that under the hood may be causing the misfire?

 

After a long frustrating journey..i finally decided to go the stealership for the diagnostic since I got worried about the Glycol contanimation. After a little test drive SA was convinced it was the Glycol conntamination and would have to do a tranny rebuild at $ 5k....I almost had a heart attack....i told him to do the glycol test on it.....he got back to me after 3 hours and told me that they found no contamination ( My heartbeat became a lil normal) however there is an internal fault on the Transmission Control Module...they qouted me that at $1100 plus 2 hrs of labour.....well i didnot argue the labour since I was relieved to find out it wasnot the glycol contamination. I know the TCM is on the passenger side footwell and its a 15 minute job..Correct me if I am wrong.

Secondly I am wondering where the location of the Oil Level Sensor/sender is..since i cant check the oil level on the dashboard anymore...i keep getting the RED screen msg ( Engine Oil Level - Visit workshop) so i would like to see if this is something that i can DIY....Glynn or anybody else..any ideas??

 

Ask a few more questions about what they intend doing to the TCU - If it's a software reflash - tell them they are expensive. The 5 speed transmission is bullet proof if you keep oil out of the TCU & service it properly. Check the TCU plug into the front corner of the transmission for O ring leaks. C230 sport coup & others have covered this in detail. The TCU is under the passenger footplate.

https://mbworld.org/forums/c-class-w...u-removal.html


Here is the Oil sensor R&R - splinter posted it a few weeks back

 

how can you fixed the P0420..code ,plz?

 

P0420 = Catalyst System Efficiency Below Threshold (Bank 1). If you have done everything else and the car is in good tune & you still get a 420 you need a new Cat.

 

i had change it but it's not working . that's why i am asking this..
then C230Krarana told me this link:

http://www.troublecodes.net/articles/catfailure/
ok i got what test equipment need, but i have no ideal means "upstream , down stream"
is's mean before Cat o2sensor(upstream) and after (downstream)?

 

Upstream is between the engine & the cat & controls fuel trim. Downstream is after the cat & tells you how the cat is working

 

I took my car into MB for the cam solenoid recall and a week later my CEL came on. I had the code read at my usual inde shop in Burlingame; code P0128 turned up. After a couple hours of digging around the forums I came upon 2 helpful threads; ammar's thread and susainav's thread https://mbworld.org/forums/c-class-w...ight-came.html. I was hoping MB dealer tinkered with the thermostat during the last recall so i can bring the car to them and make em fix it for free, but the receipt doesn't say anything regarding coolant/thermostat work. Oh wells. sub $200 for replacement doesn't seem to bad, but still sucks nonetheless! Haha

Will update once I've had this fixed and let you guys know if it worked or not...

 

After searching mbworld and mymbonline for a DIY and/or fix for our w203 M721 thermostat and coming up empty, I finally found one...elsewhere.

I thought this info would be of great help to myself, as well as to others, who might run into this problem and wanted to share it to the benefit of the community here.

First off, let me say that i take no credit for this D.I.Y and that it is courtesy of "DnBtekhnic" of Benzworld.org. Please see the following link for the original post http://www.benzworld.org/forums/w203...placement.html Since you need to become a member in order to view the pictures he has posted, I have taken the liberty of reposting HIS work & photos here for easier viewing.

"a little contribution to the forum...

M271 engine 2003 Mercedes c230 Kompressor Sport Sedan

Tools Needed --

Thermostat (T-stat) with replacement O-ring
Part# 271 200 0015 from Autohaus AZ

One jug Mercedes Anti-Corrosive Coolant or
Mercedes Approved Zerex G-05
Equal size jug of distilled water (you pour in one whole jug of coolant, then water)

Socket wrench w/ 9mm (star pattern?) bolt attachment (for T-stat housing on engine head)
8mm bolt attachment (for plastic underbelly to get to radiator drain)

Flathead screw driver

Proper catching device for the coolant

Drive up ramps or Hydraulic heavy lift (to get to drain plug and 4 screws for plastic underbelly)

Directions --

1) Drive car up ramps or lift the vehicle a good amount so you can reach all the bolts for the forward plastic underbelly just after the bumper.

2) Place catching device below RED draining cap and turn slowly until you get liquid flowing out, open the radiator reservoir cap in the engine and allow the coolant to flow out.

3) After the coolant is nearly gone or to a drip, you may now unbolt the T-stat housing (2 bolts) but first you must detach the hose attached to it. The hose has a metal tension clip around it you can detach it with a flat head screw driver – after moving the clip away from the hose, pull the hose out of the housing -- you may unbolt the housing now. The housing pulls straight out but may take a wiggle or two.

4) Once you pull the housing out, the T-stat is attached to the end; you just detach it, pull out the rubber ring, replace it, and attach the new T-stat.

5) Rebolt the T-stat housing (2 bolts, make tight), reattach the radiator hose to the housing, attach metal clip, tighten the red radiator drain plug (tight), fill up radiator reservoir with Mercedes coolant (or Mercedes approved coolant) and fill up with water. Start the vehicle, observe all the connection areas for leaks, top off the reservoir with whatever fluids you have left from the 2 jugs, seal the cap to the radiator reservoir, turn off the vehicle, reattach the plastic underbelly with the 4 bolts and restart car and look for any leaks. You should be good to go now. Good luck.

INSTALLATION NOTES -- Personally, I had to take out the air intake tub (pretty easy) to gain access to the T-stat housing the radiator hose attached to it. I used ramps to do this installation. When refilling the coolant, I used half of the Mercedes coolant, half of the distilled, water, then back to the coolant, then used the rest of the water, I also started the vehicle and topped it off when the coolant got sucked in."

[IMG][/IMG]

[IMG][/IMG]

[IMG][/IMG]

[IMG][/IMG]