Engine stalls - C220 1996 - need help
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C220
Engine stalls - C220 1996 - need help
I have a 1996 C220 . The engine stalls occasionally (about once per week). It only happens when it is really hot outside (over 90F) when I am bringing the car to a complete stop. The RPMs drop slightly below 500 and it seems like they are not corrected in time to maintain idle. The engine always starts fine immediately after it stalled. When it is colder (e.g. morning and evenings) or lower temperatures (~80F and below) I don't run into this problem at all.
The engine temperature is in the normal range 85-100C (I replaced the thermostat about 20K miles ago). Also, when it is very hot outside, the engine seem like it does not have all the power it should have. I checked the intake air temperature sensor readings yesterday using the OBDII reader and it showed 137F while the outside air temperature was about 80F. I know the air will heat up a little bit before it gets to the IAT sensor (the reading seemed a bit high to me, but the guy at AutoZone thought it is often around 130F b/c of the engine heat).
Some items that I have replaced over time are the fuel pump (original Bosch), fuel filter and fuel relay about 15K miles ago. The new Bosch remanufactured MAF sensor and spark plugs about 2K miles ago. The air filter looked clean and it was replaced about 10K miles ago.
If anyone has thoughts about other items to check, please let me know.
The engine temperature is in the normal range 85-100C (I replaced the thermostat about 20K miles ago). Also, when it is very hot outside, the engine seem like it does not have all the power it should have. I checked the intake air temperature sensor readings yesterday using the OBDII reader and it showed 137F while the outside air temperature was about 80F. I know the air will heat up a little bit before it gets to the IAT sensor (the reading seemed a bit high to me, but the guy at AutoZone thought it is often around 130F b/c of the engine heat).
Some items that I have replaced over time are the fuel pump (original Bosch), fuel filter and fuel relay about 15K miles ago. The new Bosch remanufactured MAF sensor and spark plugs about 2K miles ago. The air filter looked clean and it was replaced about 10K miles ago.
If anyone has thoughts about other items to check, please let me know.
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C220
I cleaned the throttle body today. It was dirty. I used the CRC Throttle Body and Air Intake Cleaner. Since the car doesn't stall that frequently, I'll wait and report back in a few weeks if this solved the problem.
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Here is a quick update. I cleaned the throttle body. The engine used to randomly stall prior to the TB cleaning. It has been 10 days since I cleaned the TB and the car has not stalled once.
I did have one odd occurrence the very next day after I cleaned the TB. On that day I drove the car for approx 1 hour without any issue. I stopped and had it idling for about 2 minutes before continuing. When I gently pressed on the accelerator the RPMs started going up and down btw approx 700 and 1200. When I removed my foot from the accelerator, the engine went back to normal idle at around 600 RPM (it did not oscillate RPMs up and down). I could recreate the problem in park position (with AC on or off). I finally pressed harder on the accelerator (while in park), the RPMs went up to 3000-4000 range and when I depressed the accelerator, it went back to normal idle and I could no longer reproduce the RPM up/down oscillating problem. The issue did not come back since that first day after TB cleaning. I am not sure if my TB cleaning solved the problem and this first day was due to "the computer learning" or if I still have some other issue with idle control. I had no idle issues since that first day (so 9 days now).
If anyone has any additional thoughts, please let me know.
I did have one odd occurrence the very next day after I cleaned the TB. On that day I drove the car for approx 1 hour without any issue. I stopped and had it idling for about 2 minutes before continuing. When I gently pressed on the accelerator the RPMs started going up and down btw approx 700 and 1200. When I removed my foot from the accelerator, the engine went back to normal idle at around 600 RPM (it did not oscillate RPMs up and down). I could recreate the problem in park position (with AC on or off). I finally pressed harder on the accelerator (while in park), the RPMs went up to 3000-4000 range and when I depressed the accelerator, it went back to normal idle and I could no longer reproduce the RPM up/down oscillating problem. The issue did not come back since that first day after TB cleaning. I am not sure if my TB cleaning solved the problem and this first day was due to "the computer learning" or if I still have some other issue with idle control. I had no idle issues since that first day (so 9 days now).
If anyone has any additional thoughts, please let me know.
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C220
The wires that I can see look fine - for example, wiring right next to the senors, such as air intake temperature sensor, etc.
I have not investigated the engine wiring harness in detail (I did not want to cut into it). Are there specific areas of the wiring that are non-intrusive / easy to check?
I have not investigated the engine wiring harness in detail (I did not want to cut into it). Are there specific areas of the wiring that are non-intrusive / easy to check?
