Fabia Estate (2010) Mk 2, 1.2 TSI DSG: - A really dificult problem that's been going on for a year now so can anyone tell me what this rattle is and how to fix it?

 

Background: -

1. May 21^st 2014 - DSG gearbox oil was changed, at 15940 miles, from synthetic to mineral oil free of charge under Skoda campaign reference 34F7.
2. Feb 19th 2015 - Minor front end impact damage repaired, at 23000 miles, by insurance company specified repairer.
3. The DSG has performed smoothly to date so I do not think the noise is DSG related.

 

Noise: -

1. Mid-March 2015 – At 23500 miles an annoying random rattling noise when accelerating began to happen. This 150 “taps per minute” rattle is a ‘solid’ rattle like a hammer hitting solid metal (but muted by the engine bay sound insulation) so I do not think it is pinking which is a more high pitched tinkling sound. My initial thought was that a mechanic (from the February repair) had left a spanner in the engine compartment which was rattling against something when accelerating but mechanics say it is not that.
2. The rattle is random and, when it does happen, it only happens under acceleration. It seems to come from the engine area and it can start and stop suddenly. I.e. I could have driven 10 or 50 miles with no noise then at the next acceleration it can suddenly happen for the next few miles then stop again.
3. Since June 2015 – Started to use premium grade fuel plus RedeX fuel additive to clean the combustion areas. The noise, when accelerating, still happens sometimes but it is not as loud or as frequent as it was. It may not happen for three weeks then make a reappearance.
4. Could it be related to the direct injection engine design and the use of cheap fuel causing carbon build-up on the inlet valves which then breaks off in pieces and rattle around the combustion area before passing out through the exhaust valve and entering the exhaust/catalytic converter area? If so then the use of premium grade fuel and RedeX fuel additive has not removed the carbon. It would explain the random nature of the noise but not why it only happens when accelerating and would it be a ‘solid’ rattling noise as described above?
5. The random nature means that two separate garages heard the noise whilst driving the car but it failed to repeat itself in the workshop (not accelerating) so they have been unable to identify it. Both garages confirm that the exhaust and heat shield are not loose. Internet searches have revealed nothing.
6. March 2016 - The car passed its MOT (emissions) test carried out by main Skoda dealer so exhaust and catalytic converter must be good.

Thanks in advance.

Ken

Interesting, I have had something which sounds similar with my 2009 petrol version. Happened the first time over a year ago and sounded really bad, like something falling off and getting trapped in the wheel arch. I eased off the accelerator and it stopped and didn't come back. It was then fine for months then happened again a couple of months ago (just before a scheduled service & MOT) which was followed a few days later by a refusal to start from cold so I asked the garage to check it out. They found no problem and put the start failure down to something in the fuel line which cleared itself.

 

I'm left wondering when/if it will happen again but it is behaving perfectly the rest of the time and fuel use is as good as ever (48-50 mpg on most journeys that aren't mostly motorway, 44-45 when on motorways).

 

It hadn't considered it to be fuel related but given your assessment and the start failure maybe it is although we have very different engines so I doubt it is the same exactly. Like you it has been for service (and 2 MOTs in my case) without anything being identified. 

Ist time writer.

Did anyone ever discover the cause of the 'death rattle' from n/s/f/ of the engine compartment during firm acceleration? My 2017. 1.2tsi  displays this noise that sounds like engine 'pinking' from cars years ago. Of course after the customary £100+ diagnostic test at Skoda--NO FAULT FOUND!

It's a pain but certainly stops me accelerating too much!

1 hour ago, Epsom said:

Ist time writer.

Did anyone ever discover the cause of the 'death rattle' from n/s/f/ of the engine compartment during firm acceleration? My 2017. 1.2tsi  displays this noise that sounds like engine 'pinking' from cars years ago. Of course after the customary £100+ diagnostic test at Skoda--NO FAULT FOUND!

It's a pain but certainly stops me accelerating too much!

 

Try using 99 octane fuel and see if it improves, also check your spark plugs.

Faulty knock sensor if doing what Sep suggests does make a difference.

 

They are highly reliable and even with one not working or disconnected the mapping is so accurate these days that it is unlikely that an engine would ever pink like one in the bad old days, the engines are mapped to run just on the safe side of detonation and ignition is retarded and/or fuelling enrichd on the individual cylinder as soon as one detonation knock is sensed.

My random rattle turned out to be loose rivets in the charger drive pulley clutch plate

Thanks guys. It's not pinking, just reminiscent of that noise. It's like a box of marbles has suddenly come to life down behind the glovebox area!New plugs were fitted 7,000 miles ago. I use top grade juice. My Yeti has the DSG box and the problem makes itself heard under firm acceleration (kickdown). I really think I'm going to have to live with ths, but it ain't right!

I do appreciate members offering ideas, perhaps something will come up at next service date.

Cheers.

@EpsomWelcome.

Your Euro 6 1.2 TSI has a cam belt so different from the euro 5 1.2 TSI here with a timing chain.

?

How many miles has your car done.

What is Top Grade juice, is it E5 97 or 99 octane you buy?

 

 

Edited 12 October, 20232 yr by toot

Hello. The Yeti has done 36,000 now. I use the 'top price' petrol at my B.P station....99 Octane.

1 minute ago, Epsom said:

Hello. The Yeti has done 36,000 now. I use the 'top price' petrol at my B.P station....99 Octane.

Though Looking at the chart- BP Supreme may be 97 Octane.

Just now, Epsom said:

Though Looking at the chart- BP Supreme may be 97 Octane.

 

Just now, Epsom said:

Though Looking at the chart- BP ULTIMATE may be 97 Octane.

 

It is 97 ron minimum.

Maybe put in some Tesco Momentum 99 (99 ron minimum).   The other 99 ron Min are Shell V-Power or Esso Super Unleaded, 

but then the Sansbury Super unleaded 97 ron Min might sometimes exceed that as others can.

As you see same names but not the same formulation.

 

Winter Grade Diesel & Petrol starts being distributed in Scotland and the north of England at the end of this week until March. 

and down the UK as the weeks go on.

I'll try a '99' variant next fill up. Thanks so much for your trouble.

5 hours ago, toot said:

It is 97 ron minimum.

Maybe put in some Tesco Momentum 99 (99 ron minimum).   The other 99 ron Min are Shell V-Power or Esso Super Unleaded, 

but then the Sansbury Super unleaded 97 ron Min might sometimes exceed that as others can.

As you see same names but not the same formulation.

 

Winter Grade Diesel & Petrol starts being distributed in Scotland and the north of England at the end of this week until March. 

and down the UK as the weeks go on.

I had an online search for octane testing, but all I could find are overpriced tubes for ethanol content testing.

Does anyone know how the octane rating of petrol is tested?

2 hours ago, EnterName said:

I had an online search for octane testing, but all I could find are overpriced tubes for ethanol content testing.

Does anyone know how the octane rating of petrol is tested?

 

It isn't tested, it's formulated using an additive pack which is mixed with the base spirit before being shipped.

There is a test for octane rating - it uses a test engine and compares against 2,2,4 -Trimethylpentane and normal Heptane.

You can buy a lab machine (for US$ 2000 😬) which, it is claimed, can give reasonably accurate results. Cheaper to buy a tank of 99 and check the knock sensor.