# Camshaft Position sensor?



## TomBorehamUK (Feb 2, 2014)

Hi guys, driving home last night and the EML came up

Scanned it and got the fault: Camshaft position sensor "A" circuit (Bank 1 or single sensor)

Cleared it, then took it out and hasn't come back up yet or this morning on the way to work.

Can anyone shed any light on this?


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## TomBorehamUK (Feb 2, 2014)

Bump?


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## Hoggy (May 8, 2002)

Hi, As no one has answered.
Not a lot of help, as not sure where the connections are for that, so can't say check/clean connections.
It's only there to ensure engine fires on 1st upwards stroke of piston, rather than a few spins, so won't really cause any real probs.
Hoggy


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## TomBorehamUK (Feb 2, 2014)

Thanks Hoggy, that at least puts my mind at rest that I'm not going to have serious damage, will look into Cleaning or replacing the sensor soon


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## mullum (Sep 16, 2011)

I replaced my sensor but the error returned. Must be the cables or the connectors to the sensor rather than the sensor itself.


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## TomBorehamUK (Feb 2, 2014)

mullum said:


> I replaced my sensor but the error returned. Must be the cables or the connectors to the sensor rather than the sensor itself.


Well I've had mine scanned properly, it seems to show that my Crankshaft and camshaft are out of sync and that it's not just a faulty sensor :?

Time to consider a £400 full cam belt change at TT shop then...


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## Hollywood (Jan 27, 2009)

I had the same faulty code and i resolved by changing the cam chain tensioner.
Is your a BAM engine?


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## TomBorehamUK (Feb 2, 2014)

Hollywood said:


> I had the same faulty code and i resolved by changing the cam chain tensioner.
> Is your a BAM engine?


Mine is a BAM engine, I am leaning towards the hydraulic tensioner as this isn't usually changed along with the cam belt which I'm presuming if failed would lead to a slack belt and the camshaft and crankshaft then reading out of sync?

Just thought I may as well get the lot while I'm there for peace of mind


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## L33JSA (Jun 30, 2010)

I take it it's a correlation code?

If the hydraulic cambelt tensioner was that loose then your cambelt would have probably come off by now so it's doubtful that it is this as it would have to have jumped a tooth or 2 for it to be out enough to generate a code.

Have you had the cambelt done recently or are you aware of it being done recently? How long has the code been showing up for?

Have the timing marks been checked to see if it lines up? if they do then there's a good chance that it's the camchain tensioner at fault that links the camshafts together rather than the cambelt.


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## TomBorehamUK (Feb 2, 2014)

L33JSA said:


> I take it it's a correlation code?
> 
> If the hydraulic cambelt tensioner was that loose then your cambelt would have probably come off by now so it's doubtful that it is this as it would have to have jumped a tooth or 2 for it to be out enough to generate a code.
> 
> ...


Hi Lee, was hoping you'd show up 

Right OK then it may not be that as I'm guessing if it's jumped a tooth or two it may be running pretty rough and mine seems to run just fine.

I have a record for the cam belt being done at 65k miles along with a new water pump, alternator and auxiliary belt in December 2012

I bought the car at 68k and it's now at 69k, there was no engine light but I scanned it anyway 300 miles ago and it came up with the Camshaft position sensor fault code, cleared it, now the engine light comes up every now and then along with that fault code. So it may have been there for longer but hasn't been throwing up an EML?

I haven't had the timing marks checked yet as I was advised by the bloke to be ready for whatever was needed thereafter which I'm not until I get paid...


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## L33JSA (Jun 30, 2010)

Hmmmm.....ok in that case since it's had a very recent cambelt it's looking more and more likely that it has been incorrectly timed up I'm afraid in which case it's basically another cambelt job is required.

If you willing to spend half an hour of your time you can check the timing marks yourself on your camshaft sprocket and on your flywheel to see if they tally up - this would tell you for sure.

Oh & surprisingly enough it will 'appear' to run ok even if it was a tooth or 2 out surprisingly - although it does sometimes make it harder to start - requiring a few cranks for it to fire.


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## TomBorehamUK (Feb 2, 2014)

L33JSA said:


> Hmmmm.....ok in that case since it's had a very recent cambelt it's looking more and more likely that it has been incorrectly timed up I'm afraid in which case it's basically another cambelt job is required.
> 
> If you willing to spend half an hour of your time you can check the timing marks yourself on your camshaft sprocket and on your flywheel to see if they tally up - this would tell you for sure.
> 
> Oh & surprisingly enough it will 'appear' to run ok even if it was a tooth or 2 out surprisingly - although it does sometimes make it harder to start - requiring a few cranks for it to fire.


Damn, as I feared..
Thinking back I wasn't much impressed of the garage he took it to when I asked to check under it...

Would you be able to walk me through checking the timing?


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## mullum (Sep 16, 2011)

This sounds scary for me.
In the summer I had my cambelt done whilst on holiday, some may remember the thread. I was well and truly shafted price wise too (I believe £700 for a cambelt and securing a few loose engine mounts is excessive ?).
Anyway this camshaft sensor error was since then - and that garage is 6 hours drives away in Devon !
The only other event which sticks in my mind was when I had cruise control fitted (not long after the cambelt) - which involved some ecu rewiring. When he started the engine there was an awful noise (timing ?). But then he tried again and all seemed normal. Since then I've replaced the camshaft position sensor but the error returned. Car does start first time and seems to run fine, although fuel consumption is very high (never above 20mpg but recently I've done only short town drives).


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## L33JSA (Jun 30, 2010)

TomBorehamUK said:


> Would you be able to walk me through checking the timing?


Yup. Very simple.

1. Remove crossover charge pipe
2. Unclip the cambelt cover - one metal clip at the front that you can see and one that you'll have to feel for round the back of the cover near to the brake master
3. Pull the cover back slightly but DON'T try and remove it fully because chances are you'll crack and damage it doing so.....and if you don't damage it pulling it off you almost certainly will trying to put it back on
4. Jack the offside of the car up and use an axle stand to secure the car so it doesnt drop.
5. Remove the rubber bung from the gearbox bellhousing
6. Make sure the car is out of gear
7. Use a 19mm multipoint ring swan neck spanner or a multi point socket & ratchet and put it on the main crankbolt
8. Rotate the engine clockwise until you can see the mark on the flywheel sit central in the gearbox bell housing hole










9. Next get a small mirror (I doubt you'll be able to see otherwise) positioned inside the top of the cambelt cover so that you can see the timing marks on the exhaust cam sprocket and the top of the camcover itself

It should look like this










If it doesnt line up and it looks like this.....










..or the mark is over to the other side then your timing is out.



mullum said:


> Anyway this camshaft sensor error was since then


Sounds like your cambelt has been done wrong too I'm afraid - so not only were you shafted pricewise you were shafted twice as they haven't done the job properly. [smiley=bigcry.gif]


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## mullum (Sep 16, 2011)

Thanks for the reply Lee
Oh dear :-( 
Does that mean it needs replacing again or just adjusting somehow ?


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## L33JSA (Jun 30, 2010)

Cambelt needs replacing & adjusting yes.

I'd speak to them about it if I were you although it will probably cost you the same in petrol as it will to get the job done again by someone else.


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## TomBorehamUK (Feb 2, 2014)

L33JSA said:


> TomBorehamUK said:
> 
> 
> > Would you be able to walk me through checking the timing?
> ...


Cheers Lee, I'll let you know how I get once work allows


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## brian1978 (Jul 10, 2013)

L33JSA said:


> Cambelt needs replacing & adjusting yes.
> 
> I'd speak to them about it if I were you although it will probably cost you the same in petrol as it will to get the job done again by someone else.


 [smiley=bigcry.gif]

Try phoning them and email some photographic proof if you can. Try for a refund for the labour. You just never know you might get some sort of partial refund. A bit of a long shot but you never know.


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## mullum (Sep 16, 2011)

Good suggestion Brian, cheers. And thanks again Lee.

Before I do, is there any way it could have gotten out of alignment since they fitted it ?
I'm thinking of the day I had the cruise control fitted and the loud noise on ignition. Or could that have been a symptom of their misalignment ?
And I take it that a faulty cam pos sensor couldn't cause the cambelt to "fall out" of alignment ?


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## L33JSA (Jun 30, 2010)

Only way it could be put out of alignment is if the cambelt has jumped a tooth.....if it has somehow done this then it's likely the tensioner is failing. It's not unheard of but very rare for a cambelt to skip a tooth - something is very wrong if it has. Either way it's their issue.

Faulty cam sensor can't change the mechanical timing of an engine.

Loud noise - would need to hear it - it could be anything.


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## mullum (Sep 16, 2011)

Sure, the best way I can describe it is that it was a noise like the pistons hit something - but I'd never know what that would sound like tbh.
Like I say it was after the ecu was rewired for cruise control. I wouldn't be surprised if the guy who fitted it had suspicions about what happened but didn't want to say ! It could have been a coincidence rather than there being any connection - but it was just that one time right after reconnecting the ecu.


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## TomBorehamUK (Feb 2, 2014)

.


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## L33JSA (Jun 30, 2010)

The clue is in the steps...  

4. Jack the offside of the car *up* and use an axle stand to secure the car so it doesnt drop.
7. Use a 19mm multipoint ring swan neck spanner or a multi point socket & ratchet and put it on the *main crankbolt*

However one thing I forgot to mention is that you'll need to remove the undertray to get to the crankbolt.


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## TomBorehamUK (Feb 2, 2014)

So it seems my timing is OK.
Was a PITA as the rubber bung wasn't there so everything was brown making it hard to find the timing mark.

So assuming i'm right and the timing is fine what's next?


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## L33JSA (Jun 30, 2010)

OK....so that's a massive plus then.

I would in this order do the following..

1. Check the wiring to the camshaft sensor.
2. Change the camshaft sensor
3. Check the camshaft timing (need to remove the rocker cover)

There's not an awful lot else it could be after doing all this^


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## TomBorehamUK (Feb 2, 2014)

L33JSA said:


> OK....so that's a massive plus then.
> 
> I would in this order do the following..
> 
> ...


Thanks Lee,
OK the first two are Self explanatory 
How would the camshaft timing be checked?


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## L33JSA (Jun 30, 2010)

You need to check the positioning of the cams when the cambelt is in the timed up position.

This diagram explains it..


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## TomBorehamUK (Feb 2, 2014)

L33JSA said:


> You need to check the positioning of the cams when the cambelt is in the timed up position.
> 
> This diagram explains it..


Simple enough, thanks


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## TomBorehamUK (Feb 2, 2014)

And If the camshaft timing is out?


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## L33JSA (Jun 30, 2010)

TomBorehamUK said:


> And If the camshaft timing is out?


It'll need re-timing properly....I'll be honest though I really doubt this will be the case unless it's been out before.

There a slim possibility the camshaft tensioner might be goosed but usually you would hear it rattling first or the chain catching the rocker cover.


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## TomBorehamUK (Feb 2, 2014)

L33JSA said:


> TomBorehamUK said:
> 
> 
> > And If the camshaft timing is out?
> ...


There's a ticking on cold start up when the car is at 1200 or so revs, don't think I hear it after it about 30 secs when it settles at 800ish. Not sure whether that would be related or not though.
I'll have a proper listen and probably get myself to a specialist then


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## L33JSA (Jun 30, 2010)

TomBorehamUK said:


> There's a ticking on cold start up when the car is at 1200 or so revs, don't think I hear it after it about 30 secs when it settles at 800ish. Not sure whether that would be related or not though.


There is a possibility...


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## TomBorehamUK (Feb 2, 2014)

L33JSA said:


> TomBorehamUK said:
> 
> 
> > There's a ticking on cold start up when the car is at 1200 or so revs, don't think I hear it after it about 30 secs when it settles at 800ish. Not sure whether that would be related or not though.
> ...


Hmmm... :?


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## bboy80 (Jul 29, 2013)

I had the same fault code, had to have a new belt fitted and aligned.

£250 though so can't complain.


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## L33JSA (Jun 30, 2010)

Out of interest did you take any pictures when you checked the timing?


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## TomBorehamUK (Feb 2, 2014)

L33JSA said:


> Out of interest did you take any pictures when you checked the timing?


I attempted to, though no point uploading them as you can see sweet f all in them.


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## oz_p (Feb 7, 2011)

L33JSA said:


> TomBorehamUK said:
> 
> 
> > Would you be able to walk me through checking the timing?
> ...


Sorry to hop on the thread but was looking as have had the above sensor replaced last year, anyway is there meant to be a rubber bung covering the hole in the pic above?

I ask as mine doesnt have this, should it!?!?


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