camshaft sensor

[SD1too]

Originally Posted by Steve42

don't think its a intermittent fault as if I clear the code its straight back .

If the engine sometimes starts I'd say it must be intermittent because MG Rover says that a faulty camshaft sensor will prevent the engine from starting.

Simon

[pab]

Originally Posted by SD1too

If the engine sometimes starts I'd say it must be intermittent because MG Rover says that a faulty camshaft sensor will prevent the engine from starting.

Simon

That's how this item fails, intermittent starting problems with a hot engine. With a cold engine, no problem.

[Steve42]

thanks mike.

sd1too.
well it starts up most of the time ok. so that adds up with what you say.
have also read on the site that with some 75s it would start up and drive ok. but when engine was warm would cut out and not start up again till cold.
mine seems to start up most of the time ok and has never stopped . so you could be right with that intermittent fault.

it all started when I replaced the sliver resistor for the gold one for the cooling fan so had the front bumper off.
but I would have thought that wires for the sensor would be well away from that.
mind you it is a rover so who knows

[Steve42]

pab that's what I have always thought about cam sensor.

[pab]

Originally Posted by Steve42

thanks mike.

sd1too.
well it starts up most of the time ok. so that adds up with what you say.
have also read on the site that with some 75s it would start up and drive ok. but when engine was warm would cut out and not start up again till cold.
mine seems to start up most of the time ok and has never stopped . so you could be right with that intermittent fault.

it all started when I replaced the sliver resistor for the gold one for the cooling fan so had the front bumper off.
but I would have thought that wires for the sensor would be well away from that.
mind you it is a rover so who knows

The primary object of this sensor is to inform the ECU of the position of the camshaft to start the engine. The sensor is immersed in oil and becomes coated which then makes the signal hard to depict for the ECU, simply clean and refit.

When the sensor becomes aged and toward the end of life, starting issues happen with a engine up to temperature. If this occurs remove sensor and place in deep freeze and try with the warm engine to decide if the unit has failed.

This sensor is only required to start the engine, no running issues should occur.

[Steve42]

thanks pab.

im more than happy to replace it with a new one.if I can get one that is.
only thing I have noticed over the last two days is the mpg has dropped.
that's one of the reasons for the post was to see if it would affect the mpg.
if not then need to look into that too.

like the idea of sticking it in the freezer never come across that one before

thanks all

[Mike Noc]

Originally Posted by SD1too

If the engine sometimes starts I'd say it must be intermittent because MG Rover says that a faulty camshaft sensor will prevent the engine from starting.

Simon

Not always Simon.

This is what they say in an early version of Rave about the K4:

The half moon cam wheel reluctor enables the ECM to provide sequential fuel injection at start up, but it can no longer
provide a back-up signal in cases of CKP failure. If the CMP sensor signal is missing, the engine will still start and run,
but the fuel injection may be out of phase. This will be noticeable by a reduction in performance and driveability.

It seems strange that the K6 description is different - is it correct? Given the increase in fuel consumption and the delayed starting maybe Steve's original thoughts are on the right track.

As you know I drive a diesel and they definitely can't start with a failed cam sensor, and as they inject fuel directly into the cylinders it's easy to see why. Has anyone tried it with a V6?

It will be interesting to see if Steve's fuel consumption improves with a new cam sensor.

[SD1too]

Mike,

According to RAVE, the effects of a faulty camshaft position sensor seem to differ between the MEMS (1.8) and Siemens (KV6) engine management. I have checked and it definitely states that a KV6 will not start if the camshaft sensor is faulty. Steve has a 2.5 V6.

Simon

[Mike Noc]

Yes quite agree, and I did start my first post with "if it can start".

There are a few errors in Rave that we are already aware of, and given the noticed increase in fuel consumption which could be explained by the engine firing 180 degrees out, it did sound like a possibility.

The cam sensor will have two states - can it fail in such a way that the engine can start with the cam out of phase?

[Dorset Bob]

Hi Steve,
I had the same problem with mine and it is very easy to change the cam sensor.
Your car is about the same age as mine, so I think it will have a sensor with integral wiring. I could not find ones of those (NLA from Rimmers) and the later ones have a separate link lead.

If you take of the front cover, the cam sensor can be found adjacent to the oil filler cap.
It is only held in by one bolt and the wiring just clips in:










The original looks a much better quality item, but fitting a new one solved my starting problem.