indabenz

I recently started to get a sluggish response from the car when it is cold.once it warms up (usualy takes a few mins) its fine. The car starts right up when cold but if i want to rev it seems to skip...(i would say choke but it's more of a cut off) this problem is complety gone when car is at normal temp. only other thing is that if I want to restart the car when it is warm but has been sitting for over an hour the starter rolls for about 3-5 secs b4 it starts .this again only happens if the car is warm .if I let the car completely cool down it starts perfectly.

indabenz

Anybody? Any ideas ?

Ameen

coolant temp sensor??

indabenz

The temp gauge seems to work fine a but I'm goin to read up on exactly what the CTS does ok. Thanx

epowers777

thers 2 temp sensors one is guage one talks to computer. turn ur ac on it should kick ur front fans on if it doesnt i imagine its bad.

indabenz

oh ok .fans are fine . both spinning.

ps2cho

IIRC there is a thread over at peachparts by Arthur Dalton on how to test the temperature sensors voltage. Both sensors should read the same voltage/resistance (can't remember)....Do a search over there under his name. It was "relatively" recent.

The temperature sensors do most of the work once the engine is warm though.
When's the last time the O2 was changed?

indabenz

o2 sensor was my first guess..I just got the car a few months ago .not a lot of records.I traded for my old jeep cuz ac compressor wasn't working , so I got one from a junkyard, new o rings and she's ok.. I put iridium plugz was nice for a while but just recently started this issue. I'm not a mech so I will mention it to my mechanic .just wanted to get some ideas b4 i have to pay 75 $ to trouble shoot .my mileage seems to have gone down as well getting 18 avg mpg but i do have a heavy foot..was better b4

This is my 3rd w124 300e I love these cars so i am also picky cuz I know how well they can run even if they're old. Sometimes my mech thinks im a pita cuz i fuss about this stuff but i just figure if i drive an old car at least take car of it and don't let things pile up or i will be in trouble.

also I hear like a air pressure buildup and release every once in a while ,is there a way I can check for vacuum leak myself? but then the problem would be all the time not intermittent no?

ps2cho

Ditch the iridium plugs as they are wrong for this engine to start with. You want Non-resistor type Bosch, NGK or Nology.

Don't go for a troubleshoot at an indy yet....If it's only sluggish when cold, it is probably something playing up before the system gets into closed-loop. I'd start with the O2 sensor seeing as you have no records. 18MPG isn't too bad.

As for vacuum leaks, start with the idle air hoses that attach to the idle control valve. There are 4 total. 2 On the ICV, 1 on the block -> valve cover, 1 from valve cover -> air intake assembly. They are usually rock hard and/or cracked and can be a vacuum leak.
Check for vacuum leaks using carb cleaner. Just run the engine and spray all over any vacuum hoses and listen for any change in RPM.

indabenz

Ok thanx I will try this tomorrow hope fuly I get some time, so iridiums aren't good huh..too bad cost alot .I had a bmw b4 and they made a huge difference in performance and the mileage on the car was at least 10% better ..the iridiums seemed to make this mercedes alot smoother than the previous plugs as well but that could be because the old ones were.....old. Once its warmed up he car is really smooth and quiet. not bad for a car w 260000 miles

epowers777

https://mbworld.org/forums/e-class-w...inks-tips.html

Read this link will tell you what spark plugs to get. Get the NGKs go on ebay and order them from the guy in united kingdom cost less than 20bucks just ordered a set from him. if you need help pm me I will give u the link