I have a 2012 Skoda Fabia with a 1.2 TSI engine.

Details are as follows: 
Engine number: CBZB 95019
Date on engine stamp: 18.7.12

Mlada Boleslav production.
 

I think this should mean that I should have the latest version of the engine and should not experience any start up rattle noise- http://m.australiancar.reviews/reviews.php#!content=recalls&make=Skoda&model=Fabia&gen=822

 

However on start up I am getting timming chain rattle.

 

I took the car to a local garage former approved skoda garage and they are saying that the timing chain needs to be replaced- although they no longer have the tool needed to measure the chain to see if it has stretched or not. 

 

I am also not sure how my engine number relates to the engine numbers listed as being when the timing chain changed:

Production change
Optimised timing chain from engine number:
•CBZ* 462774 (Mlada Boleslav).

 

Any help would be appreciated. 

 

I did a bit of digging on this a while back as were looking at getting one of these. I wrote up what I could find here:

The whole thread is a good read on the topic.

Timing chains stretch over time no matter what revision/date.  More accurately the link pivots wear, so they become more sloppy altering the link to link distance, the chain and sprocket teeth also wear down. So its vital in this engine to have regular clean fresh oil to elongate chain life.

 

The revision in 2012 meant engine oil capacity went up from 3.6 to 3.9 litres, the ignition leads were fitted with "marten protection" (ribbed trunking),  from memory, the pcv valve arrangement was modified (not sure but I seem to recall the PCV on our 2013 fabia CBZA was completely different to the one on the 2011 CBZB Octavia which had the one described elsewhere that breaks where its pushed into the camcover rubber grommet), The timing chain was different, got a different link configuration which also meant different sprockets The tensioner and guide rails were revised. Probably other things too

 

Even when relatively young, a brief rattle can be frequently heard for a second or so occasionally when starting, especially after being stood even though the chain is not particularly stretched. 

 

This is quite different from the "death rattle" which is a lot louder and alarming. That's when the chain is loose and not properly engaged in the bottom sprocket and the sprocket is fighting against the tensioners attempts to pull the chain forward that fraction into position. I hope you understand what I mean.

 

Never ever allow the engine to roll back, for instance parking in forward gear facing uphill. This forces the tensioner really back and imo damages it so loosens the chain lots with possible disastrous consequences when starting.

 

If ever I hear that worrying rattle on start, I immediately switch off, take a deep breath, then restart. So far that works, a second restart will now have more or less tensioner pushed out fully and chain properly engaged on the sprockets.

 

I think the hydraulic tensioner (which has had several revisions) has some kind of internal ratchet mechanism to stop it retracting, but from something I remember seeing somewhere on a Russian site, its a rather feeble design that can be overcome and wears/strips the ratchet in scenarios as described above, once its been forced back the ratchet is weak or u/s so more rattily starts.

 

Measuring chain length is done by unscrewing/removing the hydraulic tensioner and measuring its extension, seem to recall its limit was 78mm and mine was at 74mm so no warranty repair authorised, despise the "death rattle" on many mornings. Had to pay to have it changed. And switched from 18,000 mile oil changes to 9,000 mile oil changes.  Starting to hear those rattles again after not much longer mileage though (75,000, now 150,000) even though its the upgraded latest revision.  Although its not as bad as the original chain was.

 

If you're hearing rattles often and definitely if its "death rattle" loud, you need to address it quickly before its too late. That's far more reliable an indicator than measuring according to Skoda TPI, IMO that's a flawed method as the tensioner may be damaged and even pushed back a bit when you remove it.

 

You could always try changing just the hydraulic tensioner, that's quite a simple job, as the old one may be knackered. Otherwise its a big job to change the whole kit. 

 

Writing this brings back many stressful memories of arguing with the Skoda dealer so forgive me if I don't want to talk much more about it.

Edited 8 April, 20215 yr by xman

Many thanks both for you posts.

 

It's extremely annoying that the engine has a chain that is fitted for life but is obviously not fit for purpose but Skoda won't do anything about it. I got the chain measured when it was under warranty and it was within the limits, given the age of the car and the fact that it has been serviced in many different places I am fairly sure that Skoda will not give me anything.

 

I think I have an engine that is the older style because it has the older style plastic PCV. 

 

Thanks again

 

Jack 

It is a great pity that they couldn't get it right because this engine is otherwise quite excellent, though the turbo actuator is something that gives problems on later engines, also effecting other tsi tubos to this day so not unique to the CBZA/B engines.

It isn't just Skoda that have problems with camchains as they age, this is an age old problem going right back to the 70's when motorcycle engines started using chain driven overhead cams. The tensioner mechanisms always give problems.

The layman's perception that chains are better than belts simply isn't true, belts are easy to keep in tension and quiet but they suffer frictional losses and need changing.

 

Give me belts every time.