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VW Engine rattle after first start

Volkswagen Polo & Golf 1.2L TSI turbo timing chain

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Volkswagen Golf and Polo – Engine: CBZ 1.2L 4cyl Turbocharged TSi – Loud rattle from engine or no start.

Another common and frustrating timing issue we see regularly is the “stretched chain” always found in the Golf or Polo ‘CBZ’ 1.2 litre, 4 cylinder, turbo TSI Engine. This again, is caused by poor manufacturing materials used in the products being used in modern engines. It’s something we are seeing in all vehicles from all manufacturers.

Today though, we will be focusing on the CBZ engine and hopefully help save you thousands by explaining the symptoms and the repair required. Leaving it too long, will unfortunately end in major engine repairs as shown in the photo’s below. This poor customer unfortunately waited until total destruction occurred, which ended up costing thousands of dollars more than it had too.


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With the cylinder head removed, the damaged valves are easily identified.


What symptoms should I look for?

This is usually a very simple answer and you have probably already heard it, but the only real symptom or warning you will get from these vehicles, is a loud rattle noise from the engine, particularly on a cold start, or the first start after sitting for an hour or more. It’s a very defined noise and will usually quieten down after a few seconds, although some will continue to rattle even while driving.

Unfortunately, it is not common for a check emgine, or other warning light to illuminate once the issue has arisen, and therefor, your ears are your only real guidance on this issue.


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Once the cylinder head is repaired and reinstalled, it is then timed correctly using a new timing kit.


What causes the issue and what will happen if I leave it too long?

As described earlier, poor manufacturing materials used in the timing chain by the manufacturer are the cause of these chains stretching. This may be either a design fault or a measure of cutting costs. Either way, every CBZ engine is bound to end up having a timing chain and other relative components replaced much earlier than VW anticipated.

Unfortunately, if left un-repaired for too long, it will eventually suffer the same fate of the red Polo seen here in pics, requiring a top end engine rebuild due to pistons contacting and damaging the valves. This will occur once the chain has stretched to the point that it is allowed to jump teeth on the Camshaft gear and allowing valves to still be open whilst the piston is on its compression stroke.


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Repair complete and ready for the owner to pick up. 


What repair is required in both scenarios and how do I go about having this issue repaired?

If your vehicle still starts and runs, then you can rest assured the repair is quite minor and consists of replacing a timing chain kit with a better quality aftermarket kit, consisting of new chain, chain tensioner, chain guides and front crank seal. Other items, like timing covers, can be cleaned, resealed and reinstalled without any further issues.
In the case of the vehicle no longer starting, then the situation is a lot worse and consists of not only the replacement of the complete timing chain kit, but it will also require the removal of the complete top end assembly, in which the cylinder head is cleaned, pressure tested, new valves installed and seats ground. It will then be reinstalled with a new, quality aftermarket gasket kit and head bolts.
On completion of the repair, a diagnostic tool is then used to clear any faults, check for new faults and once satisfied, we will install any later software available for your Engines ECU.

All parts and come with a manufacturer warranty and our workmanship is also backed by a garauntee.

If you would like us to inspect your vehicle for this fault, or for further questions, prices or bookings, please call us on (03) 9484 6806 and mention that you have read this blog. We will be happy to answer your questions.

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