Golf mk4 v5 cam sensors

Question

I guess I better start with a few details on the car in question:

VW Golf IV20 valve V5 petrol engine (2.3L)~157k miles on the clock

Now the problem, it feels to me as if the car is down on power, it seems to be a bit reluctant to accelerate at anything over than a leisurely pace lower down the rev range, and even when the revs pick up it doesn't feel like it once did, I appreciate that it isn't going to drive like new after 157k miles, but this power loss seemed to happen over a fairly short period of time, rather than a gradual decay. I have also experienced the car struggling on start-up, we have always had to apply some throttle when starting the car to prevent it from stalling immediately, but the revs seem to be bouncing slightly under where the car tends to idle and the car shakes slightly when this happens.

Both myself and the other driver have seen the engine check light come on, but for both of us it went away within ~24 hours. I scanned for codes and the only fault listed was:

P0345 - Powertrain Camshaft Position Sensor "A" Circuit (Bank 2)

After a little search it seemed that this fault code is a bit vague, and I couldn't find anyone with the same model car and the same code.

My question to you is would this fault code be consistent with the behaviour I have described? Are they any other tell-tale signs which I should be looking out for? And finally is it worth clearing the fault code to see if it reappears?

Thanks

Answer 1

Inaccurate camshaft position sensor readings can definitely cause poor gas efficiency, loss of power, and inconsistent starting. These symptoms you describe appear in line with the P0345 code. If you have already tried replacing the bank 2 sensor, its worth checking the wiring and connectors for any corrosion, stress or wear.

On my own mk4 golf I incurred the same symptoms with a similar P0343 code, which turned out to be caused by a loose camshaft position sensor connector. The sensor itself was fine, and the problem went away after unplugging the sensor, cleaning the contact points on the connector, and plugging it back in firmly. I would advise tracing the wiring all the way back to the ECU if possible to check for any damage or suspect areas.