The gremlins are killing me
07-28-2022, 08:29 PM
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ML320 CDI
The gremlins are killing me
I bought a 2007 ML320 CDI with about 100k miles about a year ago. It was running ok but never great and I’ve been sorting it out replacing a lot of parts on the way. Currently runs great except between 20 and 35 mph. I’m ok with what I’ve replaced as they’ve been known items that go and I plan to try to make this my 50k/yr road warrior.
I just had a new rear SAM put in today since it was terribly corroded and programmed by the dealer (I always do my own service but my scanner can’t program the SAM). Although this fixed the rear door, retractor issues, rear hatch issues, and restored the use of my FOB, I was hoping it may correct some of the erratic signals I’m getting from engine sensors - it didn’t.
my question… does anyone know if there is a common thread like power source or terminal/wiring harness between the throttle position, the coolant temperature, and the coolant level? I’m getting thrown into limp mode due to the temperature even when I first start up or have run for miles at 80C then it jumps to +120. The dash indicates the coolant level is too low. When I plug in my other reader and monitor what I can I live stream, the one reading that jumps out is the TP actual that is jumping around like it has a loose connection (the two accelerator pedal signals are nearly the same so I don’t think that’s it). I know I will need to do injectors, but I need to figure out the electrical gremlins first. Maybe the mice had dinner but it ran way better than it does now.
I just had a new rear SAM put in today since it was terribly corroded and programmed by the dealer (I always do my own service but my scanner can’t program the SAM). Although this fixed the rear door, retractor issues, rear hatch issues, and restored the use of my FOB, I was hoping it may correct some of the erratic signals I’m getting from engine sensors - it didn’t.
my question… does anyone know if there is a common thread like power source or terminal/wiring harness between the throttle position, the coolant temperature, and the coolant level? I’m getting thrown into limp mode due to the temperature even when I first start up or have run for miles at 80C then it jumps to +120. The dash indicates the coolant level is too low. When I plug in my other reader and monitor what I can I live stream, the one reading that jumps out is the TP actual that is jumping around like it has a loose connection (the two accelerator pedal signals are nearly the same so I don’t think that’s it). I know I will need to do injectors, but I need to figure out the electrical gremlins first. Maybe the mice had dinner but it ran way better than it does now.
Last edited by bcsml320; 07-28-2022 at 08:32 PM.
07-30-2022, 03:13 PM
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1922 Ford Model T / no OBD
I think dealing with SAM is above DIY level, so don't expect too much experience on the forum. Check ML section and GLE, what is the same car for some years.
Sounds like your car was badly neglected by PO and run in salt belt?
I am not clear how you monitor your live data, but only good gauge for doing it on permanent bases is ScanGauge and their newest 3 version is having great reviews.
Temperature sensor jumping temperatures should be relatively easy to troubleshoot. If the harness is bad, most common fix is bypass new wires to the sensor.
I've been buying "TLC needed" MB for years and when starting with neglected car can be frustrating, once you fix the issue, it is not going to come back for long years.
That doesn't always happen with other things.
Satisfaction from bringing neglected car to factory spec >>>> PRICELESS.
Sounds like your car was badly neglected by PO and run in salt belt?
I am not clear how you monitor your live data, but only good gauge for doing it on permanent bases is ScanGauge and their newest 3 version is having great reviews.
Temperature sensor jumping temperatures should be relatively easy to troubleshoot. If the harness is bad, most common fix is bypass new wires to the sensor.
I've been buying "TLC needed" MB for years and when starting with neglected car can be frustrating, once you fix the issue, it is not going to come back for long years.
That doesn't always happen with other things.
Satisfaction from bringing neglected car to factory spec >>>> PRICELESS.
Last edited by kajtek1; 07-30-2022 at 03:18 PM.
