Read till the end!!

In the following cars:

Opel Astra, Corsa, Meriva, Insignia, Zafira 1.4 Turbo A14NET/NEL, B14 NET/NEL 140KM, 120KMChevrolet Cruze, Trax 1.4 Turbo, Buick Encore 1.4 Turbo,

there is a non-return valve in the intake manifold. If it is damaged, while driving with a heavy load, air under pressure from the turbine enters the crankcase through the intake manifold and the damaged valve, causing an overpressure of 0.4 bar and oil leaks:
  • from the throttle area,
  • from the gaskets under the valve cover,
  • from the oil seal on the pulley,
  • accelerated damage to the pneumothorax diaphragm valve,
  • oil leakage from the diaphragm failure onto the ignition coil at cylinder 4.

Error codes appear (not always):
  • P1101 Incorrect operation of the intake air system,
  • P0299 Boost pressure too low,
  • P0171 Lean mixture (this error often appears when the exhaust valve in the cover is damaged).

In 90% of cases, immediately after damage to the valve in the manifold, the membrane in the valve cover is damaged almost immediately. Checking whether the valve is in place takes a few minutes, all we need is a flashlight.

Step 1

We remove the excess pressure pipe in the intake manifold.

Step 2

We look into the spigot protruding from the collector. There should be a small red head at the bottom, the size of a matchhead. If it is not there, it means that the valve in the manifold is damaged and needs to be replaced.


If we have doubts about its correct operation, we can check its operation in the following way:

1. Remove the valve cover from the engine
2. Use your thumb to plug the hole in the valve head marked with a green arrow.
3. Blow with your mouth into the intake manifold stub (red arrow). If we can blow in air with slight resistance, but cannot pull it out, the valve is working properly. If the valve does not resist when trying to extract air, it is damaged.


In addition to the non-return valve in 1.4 Turbo manifolds, it sometimes happens that the pneumothorax channel at the manifold-head connection, which holds the gasket under the manifold, is damaged, causing the left air to be sucked in.

  For an additional fee of PLN 120(28 EUR), we fill in the missing part of the collector, enabling proper installation of the gasket.

When ordering collectors, please provide the collector number. The GM number is located on the top of the manifold in the location indicated by the arrow.

Please provide the diameter of the servo stub. The standard value is 8 mm.

Since 2014, collectors with the ending number 171 have had connectors with a diameter of 16 mm.


The service includes:

  • collector cleaning,
  • face milling,
  • installation of a new non-return valve,

Regeneration cost: PLN 580 (135 EUR),

We provide a 24-month warranty with no mileage limit for the above-mentioned service,

The regeneration service can be purchased in our store:

Attention !

  • Please do not send replacements for regeneration that do not have GM numbers. Most of them have a manufacturing defect, which manifests itself as a very strong suction of the oil filler cap. Such covers cannot be used or regenerated.


    • Uneven engine operation at idle speed,

      Oil leakage onto the ignition coil at the height of cylinder 4,

      P0171 error code formation (lean mixture)

      Long-term and short-term fuel correction exceeds +20%

      Only original covers are subject to regeneration.

        The cost of regenerating the cover is PLN 280(65 EUR).

Ordering a regeneration service:

  1. Damaged parts can be sent by post or courier (please secure the parts very carefully, the collector and cover are made of brittle material). The valve cover must be moved away from the manifold by at least 5 cm in the package. From time to time it happens that carelessly packed parts are damaged during transport. We are not able to open all parcels in front of couriers, so seeking compensation from courier companies is not easy.
  2. Inside, please put your shipping address, contact telephone number and information on whether you want a receipt or invoice on a large piece of paper. We issue VAT invoices.
  3. If necessary, we have ready-made regenerated collectors for replacement on site. To check availability, please have the collector's GM number ready.
  4.   When shipping our collector, we add a refundable deposit of PLN 400. We return the deposit to the indicated account after returning the old collector. The returned collector must not have any other defects.
  5. If your car is equipped with an LPG installation, it will be more beneficial for you to send your collector for regeneration. The LPG collector has drilled holes. If we send you our collector, you will have to take it to the gas company to have new drill holes inserted and the gas installation re-adjusted.
  6.   We send refurbished parts cash on delivery within 1-2 business days of receiving the package (in the event of a sudden increase in the number of packages, the time may be longer).
We provide a 24-month warranty with no mileage limit for the regeneration service.
  Please send parts to:
"MOTRONIC" ul. Małachowska 6
27-415 Kunów
tel: 570 060 078

Help in diagnosing the fault: 570060078


Chinese replacements for 1.4 Turbo manifolds have been available for about 2 years. Some of them have a manufacturing defect. The surface of the non-return valve in the collector is approximately 10 percent smaller than in the original, which means that after several months of use and even light contamination, the air flow through the valve decreases and error P1101 is generated - incorrect air flow. Removing this defect costs PLN 350. Non-original collectors can be recognized by their square connector (circled in red).

Installation of the bypass in the Opel 1.4 Turbo manifold

On average, several times a month we receive the 1.4 Turbo intake manifold with a bypass valve installed for regeneration. In this way, car owners try to avoid the costs associated with regeneration of the collector. It is true that instead of a non-return valve, a valve in the bypass is inserted, and the membrane in the valve cover is safe, but in practice, new "side effects" often appear, e.g. error P0171, i.e. a lean mixture, or error P1101, i.e. incorrect air flow in the intake system. The check valve in the manifold has a precisely defined air flow and any change up or down causes errors. In 2012, when we started regenerating collectors, we started with bypasses. After a few months, it turned out that only regeneration of the original valve restored the manifold to its factory condition.

Installing the pipe in the 1.4 turbo manifold

Several times a month, we receive the collector for regeneration, in which a tube has been installed to replace the operation of the non-return valve. We started our adventure with collectors in 2012 with an attempt to replace the valve with a pipe. We made about 20 different tubes, spent several weeks of work and were never able to achieve 100% effect. For proper operation of the collector in the full range of speeds and loads, a non-return valve with appropriate capacity is needed. However, if you decide to experiment with the tube, please be careful. If glue or silicone gets into the holes in the valve, getting it out is often impossible or unprofitable.


Properly diagnosing faults in this engine can be quite difficult. This is due to the complexity of the pneumothorax system. The crankcase ventilation system in this engine is designed in such a way that even a slight deviation in air flow causes incorrect operation of the system. Therefore, in case of problems, it is best to choose workshops that deal with Opel cars on a daily basis. However, if you have a problem with errors P0171, P1101, P0299 and determining what is damaged, come to us, we will diagnose and remove the problem within 1 day (in the case of regeneration of the cover and collector, we start at about 8 a.m. and finish at about 2 p.m.).

Each customer receives a receipt or invoice without VAT and a 2-year written warranty on parts and services.

Approximate costs:

Diagnostics:  cost PLN 280 (65 eur)

Contains :

  •   computer engine diagnostics
  •   error reading,
  •   checking fuel corrections,
  •   checking the vacuum in the intake manifold, checking the operation of the lambda sensors
  •   checking the pressure in the crankcase
  •   checking the operation of the valve cover and the plug in the intake manifold
  •   checking critical parts and places on the engine that cause problems with pneumothorax and "left air"
  • determining what exactly is damaged (no understatements such as: we'll replace it, we'll see)

We always perform diagnostics, even if someone has already determined what is damaged. Thanks to it, we are able to determine with 100% certainty what is good and what needs to be replaced, without exposing the customer to unnecessary expenses. Only this year, it happened several times that the owner of the car came with a ready diagnosis and made an appointment to replace the collector and cover. After diagnostics, it turned out that the collector and cover were functional, but the problem was completely different and repairing the fault was several times cheaper than expected.

If the valve cover itself is damaged:

 Diagnostyka:                                                 280 PLN(65 EUR)

 Disassembly and assembly of the cover:                130 PLN(30 EUR)

      Cover regeneration:                                                        280 PLN(65 EUR)

    Cover gasket:                                                                 147 PLN(35 EUR)

 Total:                                                                           195 PLN

In case of damage to the cover and collector:

Diagnostics, after repair test drive:                    280 PLN(65 EUR)

Cover regeneration:                                              280 PLN(65 EUR)

Cover gasket:                                                          147 PLN(35 EUR)

Cover replacement:                                              130 PLN(30 EUR) 

Regeneration of the poppet in the collector:     580 PLN(135 EUR)
Gasket for the intake manifold:                             63 PLN(15 EUR)
  Dismantling and installing the collector:               300 PLN( 70 EUR)

    Filling the rebate (not always):                                   120 PLN(30 EUR)

Throttle Cleaning:                                                              0 zł

TOTAL:                                                                     445 EUR