Vauxhall Cavalier Mk3 Camshaft Sensor

Re: 2.0l 1995 Cavalier with the X20XEV ecotec 16v engine (badge in grill
version)

After cleaning my Idle Air Control valve out yet again I am still getting
the engine warning coming light on (most of the time, especially hot days).
I pulled the code 92 with the trusty paperclip which states that it is an
"incorrect signal from the camshaft sensor". I have found that by
restarting the engine once it is warm that I can make it go away and then
rev above 4500 rpm. The Haynes manual that I have states that the camshaft
sensor is located "on the end of the cylinder head in the position normally
occupied by the distributor". Since I have no distributor please can
somebody point me to a picture of where this sensor is located on the ecotec
engine. A search of ebay suggests that the camshaft sensor that I need is
the new modified (bigger hole) part no 93171450 but there are only old
90458252 ones for sale just now. I expect that my sensor is fine and its
the wiring that's gone, but until I can locate it I can't check that out.
Can I buy just the clip on lead for the sensor?

Also the warm air intake shield over the exhaust manifold has rusted so that
the bottom support has come loose and is rattling while the top mounting
star? bolts look rusted. If I try to undo them they are bound to shear off.
The rattling is annoying, but from the noise the exhaust manifold could be
leaking too. Any tips for a repair?

Thanks
Al

 

Mine did that.

Tried finding a replacement in the scrappers, to no avail (either
already robbed, or already rotten).

In the end I crafted a new piece - cut an area of tin-plate from an old
"Roses" tin, and pop-riveted sections over what remained of the old
intake shield. lasted a couple of years, at least until I scrapped the
car, was a cheap and effective "repair".

 

Actually, in the cold light of day... 'twas thin alu plate that the GF
obtained from work... I think the roses solution didn't last too long.
Just a couple of pairs of pliers, formed an approximate profile and
pop-riveted that in place. As above - lasted a couple of years or so and
was going strong when the car was laid to rest.

 

Isn't your sensor sat between the cam puleys?
Most motor factors do them.

 

Also the warm air intake shield over the exhaust manifold has rusted

Thanks for the tip Mike - I will get the tin snips out at the weekend -
shame a beer can won't be strong enough.
Al

 

I don't remember seeing it when I changed the cam belt last year - can't
make it out it in the Haynes pictures.
Probably staring me in the face.
Thanks
Al

 

Code 92 can also be caused by a bad earth. Even though the code is not
linked to an earthing problem, we have seen this on a number of earlier
cavs.
With the engine running, do a wiggle test on the wiring under the engine bay
(not just the cam sensor wiring), and see if this causes the engine to cut.

 

As me140 states the cam sensor on the X20XEV sits between the cam
pulleys at the top of the engine - at least it does on an Omega,
shouldn't think it's any different on a Cav.; apart from the engine
pointing sideways;-) Sounds like the haynes manual is refering to the
8v engine..

 

Thanks for the tip - you were correct! Found the sensor connection under
the plastic Ecotec panel on the drivers side. Guess the sensor itself is
removed from the cam pulley side. Not sure where the other end of the
sensor wire connects to - it disappears off under the inlet manifold
somewhere. Hope to have a better look tomorrow.

Managed to remove the rattling warm air shield over the exhaust manifold so
the bolts were not seized luckily. The bottom has rotted away and the
supporting strap that used to attach to the exhaust manifold has come away.
Not sure how it was originally mounted - plan to go and hunt around the
scrapyard tomorrow to find a replacement.

Al

 

Loom plugs directly onto the sensor - Vauxhall have modified them now so you
need to do a bit of soldering when you fit a new sensor / harness.

 

Yes you need to take the cam belt cover off to access the business end
of the cam sensor, bit of afiddle on these engine compared with the
older stuff

 

Thanks to everybody for the helpful tips. Job done today - parts were £10
from the scrapyard and taken from a 1.8l Vectra. Here is a summary for the
future in case anybody else has the same problem.

Replacing the camshaft sensor on a 1995 Cavalier (also Vectra etc) 2.0l
Ecotec engine
(Fault code 92 "Incorrect signal from camshaft sensor")

1. Remove plastic Ecotec panel on top of engine - 2 off 5mm allen bolts.
Camshaft sensor is on left end (timing belt end).
2. Disconnect air inlet pipe at one of the jubilee clip joints.
3. Remove air filter cover - 2 spring clips and 2 philips screws. Lift off
top and air filter element.
4. Remove air filter base - loosen 3 10mm fixings and lift off. Air inlet
is slotted into plastic pipe under the headlamp and it might be a bit
awkward.
5. Take serpentine belt off alternator pulley - slacken by turning tensioner
pulley bolt clockwise with 15mm spannner.
6. Remove timing cover - 3 10mm bolts. Be careful that the washers and
rubber washers don't fall off and get lost. The bottom
bolt (just above the oil filter element) is not easy to get at- there is a
inspection hatch in the wheelarch liner that can be removed if you can't get
your fingers on it from above.
7. Locate the camshaft sensor just under the two timing gears. Undo the
torque? bolt (8mm? star socket needed). Careful that it doesn't drop out
into the timing belt like mine did!
8. Carefully pull the camshaft sensor upwards by the electrical cable out
through the hole in the top of the engine.
9. Disconnect sensor from cable by pushing in the wire retaining clip on
connector.

As they always say replacement is the reverse of the above!
To get the sensor out in the scrapyard access was restricted and I could
only get the top bolt off the timing cover so I undid the timing gear wheels
to get at the sensor.

I did take as much of the cable as I could - it goes straight into the
wiring loom behind the engine as me140 kindly pointed out. However I have
decided not to splice it in just yet as so far all appears to be working OK.

I also pinched the exhaust manifold cover shield off the Vectra. Since the
1.8l Vectra did not have the exhaust gas recirculation nonsense I had to get
the tin snips out and make a small cut-out on the LHS for the EGR pipe to
fit, but with a bit of jiggery pokery it all fits and looks the job. The
shield is fixed to the exhaust manifold with a torque bolt just like those
used on the top- it had rusted away, but luckily there was just enough left
to undo with the molegrips. No rattles at last.

Next job a small hole in the exhaust front downpipe just where it joins the
cat section by the spring joint - hoping Mr Firegum will fix that one for a
bit.

Whilst I was at it I found the crank sensor too - its just under the power
steering pump and above the front engine mount - held in with one torque
screw. Kind of expecting that that one will go wrong next week in
sympathy....

Al