CHIRPING NOISE FROM TOP BACK OF ENGINE IT APPEARS CAS SENSOR IS BAD

If it is a belt noise, sprinkling baby powder on the belt will make the noise go away. Apply liberaly with engine off onto the belt and start the vehicle. The belt may have gotten coolant on it and this will cause the chirp. Also a defective belt tensioner will cause the belt to chirp

most likely it is one of your belts or serpentine belt,probably just worn or loose, probably does it worse when turning the wheel back and forth during idle also...

Crank angle sensor =CAS DTC code 11 .
or
Cam angle sensor = CAS s work best. for sure.
i think this engine it is both !
there is no distributor it has 4 COPs coil over plug
and 1 ignitor module l , that nissan calls the power transistor pack. or PTU, the CAS on this car is really 2 sensors in one.
1 for cam angle and TDC (its a bit sloppy but back then no OBD2 rule to kill this idea)
they call it the crank sensor but is connect to the cam.

what car, what year, ? what country?

and sputter yes.
why not post exact year and car body mode.
or do like we all do
and log in and read the CAS timing , on your car.
alldata.com or buy the FSM.


here is the lest of cars using this engine.
The 1.8 L CA18DET was the last version of the CA engine to be released. It produces 167 hp (124 kW) and 166 lb·ft (228 Nm). It received a brand new DOHC aluminum head with 16 valves. The turbocharger was also upgraded to a Garrett T25 (.48 A/R) unit for increased flow capacity, and as such, was fitted with an intercooler to help prevent the onset of pre-ignition and/or detonation. Fuel was delivered via Multiport Fuel Injection. Bore is 83 mm (3.3 in), and stroke is 83.6 mm (3.29 in). An electronically controlled fuel injection system was used with 370cc injectors.
It was used in the following vehicles:

• 1987-1988 Silvia S12 RS-X
• 1989-1990 Nissan Silvia/180SX S13 (International market)
• 1987-1989 Nissan Bluebird RNU12 SSS ATTESA Limited (Japanese Market)
• 1989-1994 Nissan 200SX RS13-U Europe.
• 1985-1990 Nissan Auster "1.8Xtt" and "Euroform Twincam Turbo"

we run a 200sx in South America. Custom Turbo. ECU and all.

Our engine CAS sensor, has slots see them?
http://i177.photobucket.com/albums/w218/kartguy3/DSCF1057.jpg
see it.

This engine has no timing freeze DLC (check-conn)like most engine.
so.
hot normal idle speed, set it to FACTORY spec. 15deg. BTDC
do not guess. the ECU hates that. it assumes it is correct
and if not, will mess up big time. Set it to spec. and LEAVE IT.

if you dont have an FSM or a book showiing how to set timing
ask for one, buy one, or google for it.

if a turbo, and you guess, 4 cracked pistons is your future.
here is the fRee FSM
see page EC22 for spark timing.
http://pdf.textfiles.com/manuals/AUTOMOBILE/NISSAN/misc/

down load the zip extract it the PDF is the shop manual.

did you run the ECU diagnostics, yet?, RTM.?
for IS the Check engine lamp glowing running?

toy and nissan have the best FSM , of all.
very BIG on diagnosis, unlike USA cars.
the ECU has switch see that?
and if a crank or cam sensor misfires, it will tell you it did.
I'm sure.
the ECU has 5 modes of diagnosis. a very nice ECU.
page 186

Now the real TOPIC :
Now MISFIRE
Misfire is 50 reasons or just 3, (micro, and macro viewed logically
1: bad engine , low compression on any cylinder or all (timing belt slip is all) 150 PSI is minimum. for me. RTM
2: bad /weak/timed wrong, spark. (cas set wrong) test spark on all cylinders. and set the timing, if found way off the cam belt slipped)
never doing a 60,000 mile tune? duh factor 1?
3: bad fueling. too rich turns spark plugs (new?) black. and misfires.
lean fueling causes, bogging and lost engine power.
flooding can be caused by may things, it is , ask how to find this easy.

misfire causes the engine to shake does it?

ever consider a new cam timing belt, or do you want to risk it snapping or slipping?
all Nissans are interference engine. if the belt slips BAM, kiss off a nice motor.

I knew someone with a Ford Taurus that had the same loud chirp like a loud bird. That turned out to be the cam shaft sensor assembly if memory serves me right.

I will tell you what I would do.
I looked up the part you speak of on the internet, and found it to be inexpensive.
Hence and therefore, I would purchase one and toss it into the glove box, for a spare.
I would also carry along the necessary tools to change it out.
I have had a few cars that have developed a chirp/squeak like yours had, and have found the same as you did.
Sometimes that is all that is needed, sometimes the noise returns.
God bless your efforts.

Chirping noise under the hood is a classic symptom of a loose or bad belt. Has the serpentine belt been replaced? At 120k miles, I'm sure it is glazed and/or brittle. Check also if there are any other belts, note their condition and replace if necessary.

Try spinning the rear wheels by hand and see if you can hear the noise, if not it may need to have a load on the wheels indicating a possible bearing, or could be a loose brake pad or backing plate. Also see if anything is touching the drive axels.

The noise and the light may or may not be related. The noise may be the wear indicator on the brake pads touching the rotor (they are supposed to do that when brakes are worn) The abs light triggers off a wheel on the axle end. If you have a bad joint on the axle, it could be noisy and causing the wheel to not have the proper clearance to the abs sensor. You really need to take the wheel and brake assembly off and carefully inspect everything. Make sure all abs sensor wires are undamaged...it doesn't have to be at the same wheel that's chirping.

I would change the whole assembly... My 97 came on with the light and I replaced the assy with one from a totalled one but I did have to get a new sensor (Sensors and electronic components for reporting are always better to replace new).

sounds like a bad crankcase vent valve located underneath intake