How to - Camshaft actuator(phaser)/sprocket replacement

[AstraFasta]

Cam position sensor diagnosis on P0014 (Exhaust camshaft phasing mechanical reference position range/performance). This thread has scope readings for good and bad engines.

https://www.picoauto.com/support/viewtopic.php?t=19081

[AstraFasta]

ROOT CAUSE OF FAILING PHASERS (SPROCKETS)?
Researching cam phaser (sprocket) start-up diesel noise for a few seconds on a cold engine (may include codes p0011, p0016, etc). Some Russians and Latinos report a common "root cause". Failing "Oil pressure non-return valves". I haven't seen these "check valves" reported much in Britsh forums.

Replacing the check valve, resolved the "diesel noise" for some but not all cases. Sometimes phasers need to be replaced. The phaser "sleeves" may be sloppy but replacing them alone did not work for one mechanic in the videos below (I think previously the check valve was replaced; a new a phaser was the fix).

Still researching this so this post should is not complete or correct but more for discussion purposes.

CHECK VALVE DESCRIPTION
Said "check valve" is a small spring, metal ball, and orange plastic housing. It is located on the engine block behind the alternator. When the engine is turned off, the valve should prevent oil at the cam phasers from draining back into the engine. If the oil drains back to the engine, the phasers start without oil for a few seconds in the morning.

A Russian claimed Opel changed from a brass to a cheap plastic check valve. That may be reflected in the part numbers below. I'm not sure when that happened but maybe around 2007 or 2008.

There are other "unrelated" oil check valves around the engine, and one at at the valve cover gasket area might have the same part number.

FAILURE MODES
Failure modes may include: clogged with plastic bits or silicone sealant, broken plastic frame, spring issue.

ENGINE MODELS
The Russians are showing failing check valves on z18xer and z16xer for the Astra, Sonic and Cruze; in the forums some Astras were 2007-2008 models with this failed orange valve. Most of the cars seemed to be newer models.

TESTING CHECK VALVE
I saw a few DIY tests of the check valve with pressure gauges in the videos (or just removing the valve cover and observing if oil drains (or stays) in a hole next to the phasers).

REPLACING CHECK VALVE
It basically looks like loosen and move the alternator out of the way. Remove a cover metal plate with allen wrench. Remove the old check valve plastics. Remove the metal housing with a wood screw. Don't lose the spring, ball or plastics.

I saw some schemes to blow oil out of the engine to clear debris. Insert new valve. attach cover plate. Tighten down alternator.

FYI - The check valve is placed oppositte the oil pressure sender (another popular Astra failure item!)

PART NUMBER DETAILS
https://vauxhall.7zap.com/ro/car/a04/e/7/33-0/#40

#39 93186943 NLS
VALVE,NON-RETURN,OIL PRESSURE,CYLINDER BLOCK (SCREW-IN TYPE) (NLS.- USE 93191308 AND SUPPLY 11049133) (PRODUCTION NO. 55560356)

#40 93191308
VALVE,NON-RETURN,OIL PRESSURE,CYLINDER BLOCK (PUSH-IN TYPE) (PRODUCTION NO. 55563957)

SATURN ASTRA PART CATALOGUE
Tasca shows the part for the Saturn Astra
https://www.tascaparts.com/oem-parts...valve-55563957

Here are 2 "better" photos
https://www.newgmparts.com/oem-parts...valve-55563957

A FEW LINKS TO START RESEARCH
https://www.cruzetalk.com/threads/1-...thread.256920/

https://www.drive2.ru/l/483166092248743978/

Astra check valve replacement, russian style
https://youtu.be/hFOqi2Lb0z4?t=724

Valve replacement with engine removed from car for clarity
Astra check valve replacement
https://www.youtube.com/watch?v=X560PXJ0dCI

Phaser Sleeve (only) replacement that didn't work, phaser replacement and oil pressure testing. I think he said the owner previously changed the "check valve":
https://www.youtube.com/watch?v=dJp3UAaT_f4
https://www.youtube.com/watch?v=W_psj8zMbHA

To translate the videos, you can see subtitles in English (select CC, select the gear and select English as the language). For the russian website, just copy the link into google.com, hit enter, then click on "Translate this page"

[AstraFasta]

"During an engine oil change, it is possible for the tabs on the filter to break off and fall into the oil filter housing. If a tab has broken off, it might be lodged under the filter housing drain check valve, causing it to remain open."

https://www.autoserviceprofessional....ssure-problems

This note is for the Cruze, so may not be applicable to the Astra. Regardless, be extra careful when changing the oil filter & look for any plastic debris inside the housing areas.

Also, I have seen some broken plastic bits inside the oil filter housing (check valve or bypass gizmo) for the z18xer. I don't know if GM sells those plastics separately or just the entire oil filter housing. There are some sellers on Amazon-Alibaba of third party replacement plastics so we see what they look like; use at your own risk.

https://www.amazon.com/GJCC-Chevrole.../dp/B0B5M229JJ