Stalling

[Ferrett 1962]

Ok I got the CPS out, not too hard just took my time and didn't force anything. I checked the resistance and it was 504 but the car starts and runs well until it has been at operating temperature for a while and then fails so I carefully heated the sensor and checked again, it was 580 and climbing, still not as hot as it would be stuck to the front of the motor, should it change that much as it heats up or should it stay the same? The testing instructions do not say to test only when cold so does that mean it makes no difference and my readings say the sensor is failing with heat. Further to this I tried heating again, the first time it was warm to touch but this time I went a bit further, more to where the engine would get it to, I held it not in but a good 6 inches above a flame until it was too hot to hold but well below where it would melt the plastic part above the sensor the reading was 650 well out of range. I watched the meter drop one point at a time as it began to cool but only time will tell if this was the problem now I wait for the new part.

[Tiger]

A good drive will tell you if you solved the problem or not.. CPS is a tricky thing to test regardless of how the manual tells you so. In BMW, it is very very very common to go bad. in older MB of same era or older... not common at all. The new MB has CPS problem at higher mileage... typical symptom will be engine dying when engine is hot... pretty consistent to temperature. In winter... not so much.

Other thing with CPS is that you might notice the engine is running hotter with faulty but functioning CPS. After change, the engine runs cooler. This is observed on my friend's MB.

[Tiger]

So Ferrett 1962... what is the verdict?

[Ferrett 1962]

Still waiting for the part, $200 to buy here and even the dealer said it was on back order got it from UK for $37 incl post just waiting for it to get here.