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Bulletin: VW & Audi Oil Non-Return Valve

Audi Models Affected:  Audi A3, Audi A4, Audi A5, Audi A6, Audi Q3, Audi Q5, Audi TT
Volkswagen Models Affected:  VW EOS, VW Jetta, VW Tiguan, VW golf

Engines: Volkswagen and Audi 2.0 Petrol engines (including CBZB, CCZA, CCZB, CCZC, CDLC, CDNB, CDNC)  **This is not a comprehensive list, just the most common we see

What we are seeing is the oil non-return valve that sits in the cylinder head and controls oil flow to the top of the engine is failing either partially or completely.  The non return valve dictates the amount of oil the hydraulic lifters and the variable valve timing units (VVT) receive.

A partial or complete failure of the control valve can cause a knocking noise from the timing chain area at the front of the cylinder head, and from our experience the noise in most notable at around 1500 – 2000rpm.  The reason is the variable valve timing (VVT) unit is not getting sufficient oil flow to allow it to advance and retard as required.  This results in a pronounced knocking sound at higher RPM but generally quite at idle.

You can test if this is the problem by disconnecting the plug for the VVT solenoid, if the noise goes away then you are likely on the right track.  There is no easy fix, cylinder head removal is required to access the control valve.  With the cylinder head off, replacement is easy as the valve just slides out and slide a new one in.  If your unsure call Southside Cylinder Heads on (07) 3343 5899.  We service Brisbane, Gold Coast, Sunshine Coast and Ipswich.

A failed return valve on the right, compared to a good one on the left

Bottom side of the failed return valve

 

 

 

 

 

 

 

Non-return valve fitted to the cylinder head

Holden Cruze 1.8 Petrol Camshaft & VVT Problems

Our home grown Holden Cruze has had several different engine options since its inception in 2002.  The most popular has been the 1.8 petrol (Z18XER/F18D4), which first came out in the JG Cruze in 2009. There are two common problems we would like to discuss to help make your diagnosis and repairs easier.

Oil Flow Tubes

Firstly, a few of our customers have had problems with oil feed to the variable valve timing units after having head work or timing belt repairs carried out.  There is a small plastic tube that is being left out during re-assembly that is crucial for oil direction and flow to the variable units.  Without the tube in place, oil is not being fed to the variable unit, which triggers an engine light as well as loss of power through the rev range.  Theses tubes are located inside the camshafts at the front, right behind where your camshaft gears bolt on.  There is one for each camshaft.  Make sure these are in place before refitting the cam gears because the engine will not operate correctly without them.

Oil Coolers

Second issue is a high number of vehicles ending up with oil in the cooling system. These engines (Z18XER and F18D4) run oil coolers which are renowned for failing.  If you have oil mixing with water, check your oil cooler before racing to remove the cylinder head as this is most likely your problem.  Southside Cylinder Heads can pressure test your oil cooler for you.   The coolers are located next to the oil filter and forms part of the oil filter housing assembly.  Currently replacement coolers are only available OEM.  Southside Cylinder Heads, Brisbane’s best choice!

 

we have new camshafts available for the Holden Cruze on our online store.