Engine timing chain tensioner 1.2 TSI is one of the most critical components in a carโs power plant Skoda Yeti. Many owners are faced with the problem of premature wear of this element, which can lead to expensive engine overhauls. The design of the original hydraulic tensioner of early versions has design flaws that do not allow it to maintain the required oil pressure during a cold start.
If you hear a characteristic metallic clanging sound when starting a cold engine, this is the first signal that chain tensioner no longer copes with its task. Ignoring this symptom often leads to the chain jumping over the teeth of the sprockets, which leads to fatal damage to the piston group and valves. Owners Yeti You need to know how to recognize the problem in time and what measures to take to eliminate it.
Design features and problems of early versions
Engine 1.2 TSI (code CBZB, CAXA and others) has a reputation for complex units in terms of maintenance of the fuel and gas. The main problem lies in the design of the hydrotensioner. In early releases, a mechanism with insufficient back-blocking was used. This means that when the engine stops and the pressure drops in the lubrication system, the spring inside the tensioner cannot hold the rod in place.
As a result, the rod is pulled under the influence of tension of the chain, creating a huge gap between the tensioner and the tension bar. At the next start, when the oil has not yet reached the timing system zone, the chain begins to "hack" the tensioner body and the guide. This process is accompanied by a loud crack that scares many drivers, although sometimes it only lasts a few seconds.
Design Feature Skoda Yeti is a tight under-hood space, which makes it difficult to access the node. Replacement often requires the removal or disconnection of many auxiliary units. Oil quality This plays a secondary role; even on fresh synthetics, a defective tensioner cannot hold the chain if its mechanism is worn out or structurally flawed.
Wear symptoms and diagnostic methods
Determine the fault chain tensioner It can be not only by ear, but also by indirect signs of engine operation. The most obvious symptom is a metallic grinding or clang that occurs in the first 3-5 seconds after starting the cold engine. If the engine is heated, the noise may disappear as the oil pressure is restored and pushes the tensioner rod back.
The second alarm is a change in the phases of gas distribution, which is recorded by the onboard computer. You may notice a code error. 03411 or P0016 (The disparity between the squash and the squash). In this case, engine It can work unstable, triple or deaf at idle turns.
It is important to distinguish the noise of the tensioner from the knocking of hydraulic compensators or problems with the turbine.
- ๐ The slag of the chain is heard from the right side of the engine (from the radiator).
- ๐ Errors in the gas distribution phases appear at start-up and can be stored in the ECU memory.
- โ๏ธ The cracking stops as soon as the oil pressure reaches its working value.
Part choice: Original number vs. analogues
When replacing a node, it is critical to choose the right one chain tensioner. There are two main types on the market: early versions (which have a problem) and upgraded versions with improved locking. A simple replacement with the same one as the one from the factory won't solve the problem, and it'll be back in a couple of months.
You need to find a tensioner with a modified design of the locking mechanism. Manufacturers recommend using a part number that meets the updated specification. Often it's details from brands. Mahle, Ina or FebiThese are produced as original spare parts for the VW Group.
When buying, be sure to check the markings on the body. Older tensioners often have a red mark that is easily damaged when inspected. The new versions differ in color and design of the stopper. Do not save on this node, as the cost of replacing the chain and stars in the event of a cliff will many times exceed the price of quality. tensioner.
Step-by-step replacement instructions
Replacement process chain tensioner on Skoda Yeti 1.2 TSI It requires a certain set of tools and accuracy. The work begins with the removal of the protection of the engine and the disconnection of the battery. Next, it is necessary to dismantle the decorative housing of the HRM and, if necessary, remove the generator or other interfering units to access the mounting bolt.
Before starting work, make sure the engine is cold. This is important because when heated, the metal expands and the gaps can change. Unscrew the tensioner mount bolt located at the bottom of the cylinder block on the radiator side. Be prepared for the fact that when you unscrew a small amount of oil will leak out.
Installing a new node requires consistency.
- ๐ง Clean the seat from dirt and old sealant.
- ๐ ๏ธ Install a new tensioner, not forgetting about the O-ring.
- ๐ฉ Tighten the bolt with the moment specified in the service book (usually about 20 Nm).
- Less than 60,000. km
- 60-120 thousand. km
- More than 120 thousand km
- Second owner
Checking the chain and associated nodes
Replacing the tensioner alone may not be enough if the chain has already managed to stretch. To be fully confident in the reliability of the timing system system, it is necessary to check the length of the chain and the condition of the guides. A stretched chain, even with a new tensioner, can jump over the teeth, which will lead to the valves meeting with the pistons.
The check is carried out by measuring the length of the chain at a certain number of links or by evaluating the backlash when the crankshaft is rotated. If the chain is stretched by more than 1%, it must be replaced with the tensioner. Also look around. guide strips. They often wear out and crumble, which leads to the appearance of metal shavings in the oil.
Typical maintenance errors
One of the most common mistakes is trying to โblowโ an old tensioner with compressed air to check its performance. This is a completely incorrect method, since it does not mimic the operation of the oil pump and does not give an idea of the real ability of the unit to hold pressure.
Another mistake is to install an old tensioner if it has been removed. Some mechanics try to just press the rod and fix it with wire. This is a temporary solution that often results in a failure of the mechanism at the most inopportune moment. Hydraulic tensioner This is a disposable node that must be replaced at the slightest sign of wear.
Compatibility table and details numbers
For convenience of selection of spare parts below is a table with the main articles suitable for engines. 1.2 TSI on Skoda Yeti. Please note that numbers may vary depending on the year of the car and the engine modification.
| Part type | Original number (VAG) | Analogue (Mahle/INA) | Note |
|---|---|---|---|
| Chain tensioner | 03C 109 469 B | 03C 109 469 D | Updated version |
| Timing chain | 03C 109 119 H | 531 0021 10 | For engines until 2012. |
| Crankshaft sprocket | 03C 109 111 F | 531 0023 10 | Check the wear of your teeth. |
| Upper guide | 03C 109 469 A | 531 0024 10 | Plastic often breaks down. |
โ๏ธ Preparation for the tensor replacement
Prevention and operating tips
To prolong the life of the HRM system, it is necessary to strictly observe the rules for replacing motor oil. For engines TSI it is critical to use approved oils VW 504 00 / 507 00. Dense or poor-quality oil will not be able to quickly create pressure during cold start, which will increase the impact load on the chain and tensioner.
Do not allow the engine to work at extremely low revs under heavy load. This creates cavitation in the oil system and reduces the efficiency of the hydraulic tensioner. If you hear a strange noise at launch, do not delay the visit to the service.
Before buying a new tensioner, be sure to consult the seller about the date of production of your car, as the parts numbers have changed several times.
โ ๏ธ Warning: Never try to start the engine several times in a row if there is a strong slag of the chain. This can cause the chain to be instantly stretched and jumped over the teeth, requiring a complete motor replacement.
โ ๏ธ Note: When replacing the tensioner, be sure to replace the sealing ring. The old ring may lose elasticity and begin to skip oil, which will lead to oil starvation of the nodes of the timing system.
Regular check of the condition of the circuit and timely replacement of the hydraulic tensioner with an updated version is the only guarantee against expensive repair of the 1.2 TSI engine.
Conclusion
The GPM system Skoda Yeti 1.2 TSI It requires a lot of attention. The chain tensioner is a weak link, which, when it fails, poses a threat to the entire engine. Timely diagnosis and replacement with a strengthened version of the node can avoid catastrophic consequences.
Ignoring symptoms such as metallic clanching during cold start is unacceptable. The cost of repairing the engine in the case of chain jumping is incommensurable with the cost of prevention. Trust the replacement to qualified professionals with experience with TSI family engines.
What if the slack appeared after the tensioner was replaced?
If the clang appeared after the tensioner was replaced, it could mean that the chain is already stretched. In this case, you need to check the length of the chain and, if necessary, replace the entire set of timing system (chain, stars, tensioner, guides).
Frequently asked questions (FAQ)
How long does it take to replace the chain tensioner on the Skoda Yeti 1.2 TSI?
On average, the replacement takes from 2 to 4 hours, depending on the skill of the master and the need to remove additional nodes to access the tensioner. In dealerships, time can be extended due to strict regulations.
Can I drive if I hear the squeak of the chain at launch?
You can drive, but only until the first major repair. The clang means that the chain is already hanging and there is a risk of it jumping. It is recommended to replace the tensioner as soon as possible to avoid engine failure.
Should I change the chain if I just changed the tensioner?
It depends on the mileage and the state of the chain. If the mileage is less than 80-100 thousand kilometers and the chain is not stretched, you can limit yourself to replacing the tensioner. With large runs or errors in the phases of the timing, the chain is better to replace immediately.
What sound does a stretched chain make?
The sound resembles a metallic clang or crackle that is heard in the first seconds of starting a cold engine. When working the heated engine, the noise may disappear or become less noticeable.
Can I use the old scalp again?
No, the hydraulic tensioner is a disposable node. Once removed, its locking mechanism may be disrupted and it will not be able to provide the required oil pressure, leading to repeated breakage.