Idle speed DIG-S

Does anyone knows the idle speed of the DIG-S engine.

Mine is as low as 750-800 and it should be more like 900 shouldn’t it?

I hear some rattling from the engine which does not sound too healthy.

Perhaps faulty tensioners? Idle tensioner?

The engine has 125.000 km on it.

Any suggestions?

Kind regards
JCT
 
OP
OP
J

jct

Oh and as soon as I turn the ventilation on the idle speed increases to 900 which in my ears sounds healthier.

Otherwise the engine sounds really great and has a lot of power to it.
 
Hi,

I have a non dig-s model but I think the bottom ends are very similar/the same, does the rattly noise only happen at idle? And does the whole car vibrate very gently at this point? If so I believe it is because these engines have 3 cylinders, causing them to be imbalanced, and the balancing applied is tuned for when the car is driven and not when it is idling, causing the engine to shake quite a lot at idle with no load (lights off, A/C off etc.).

Mine idles at around 750rpm with everything off, so I think this is normal too. Once the A/C is turned on the engine revs higher, due to the A/C compressor using engine power, to around the 1000rpm mark on the dial. I think modern engines idle so low to reduce fuel use at traffic lights etc. for models without stop/start.

Hope this helps :)
 

SplanK

Site Supporter
I find my DIG-S to be a 'noisy' engine at idle - mostly from the injectors! In fact have now had 3 cars with direct injection and they have all been a lot more noisy at idle compared to port injection.

Idle speed is around 750/800ish

Without hearing what yours sounds like, it would be difficult to tell you if the noise coming from your engine is right or not. There are a number of things that could cause a noise from the accessory or idle pulleys, cam chain, something vibrating (something like a headshield), or just normal!
 
OP
OP
J

jct

Then the idle speed should be fine.

I think the injector noise is not that loud. I heard louder ticking from other VW direct injected engines.

But I guess as the injectors wear they become even louder.

The rattling I hear is coming from the left side standing in front of the car. Since the idle speed is quite low I guess some of the pulley’s could be rattling. When I turn on the ventilation the idle speed increases to around 900 and the rattling becomes quieter.

Since I also have squeezing noises from the belt or belts I have decided to let my garage change the belts to GATES belts as recommended by a member here. In the same time I will let the pulley’s have a check if they have excessive wear.

The rattling is more audible when standing at the side of the car next to the engine. It’s not a mechanic noise like a chain noise but more a vibrating noise from a part.

I also read that the super charger clutch pulley could cause squeezing noises. Perhaps the pulley is on for a change? The car has run 125.000 km.

Kind regards
JCT
 

SplanK

Site Supporter
I have a post on here somewhere where I had to have both supercharger and aux belt tensioners replaced [although im still not sure if I was done over by the garage and possibly only 1 needed doing - something didn't sit right with the fact that they didn't know it was a supercharged car at first and then all of a sudden after I told them, the other tensioner needed replacing - either which way, it fixed the issue at least!]

One of the noises was a clacking noise but the other was more like a 'rattle can' - have a look as there is a youtube link in there to a video of it happening. Might be completely different as you mention yours is a vibrating/resonance type noise.

As I say, there are many noises and trying to convey that over text is challenging - if you can get a video of it then that would really help, but hopefully the garage should be able to identify the cause.
 
OP
OP
J

jct

I will let you know what the garage finds out.

Do you know if I simply can upload a video from my iPhone and attach it here?
 
Hi,

I have a non dig-s model but I think the bottom ends are very similar/the same, does the rattly noise only happen at idle? And does the whole car vibrate very gently at this point? If so I believe it is because these engines have 3 cylinders, causing them to be imbalanced, and the balancing applied is tuned for when the car is driven and not when it is idling, causing the engine to shake quite a lot at idle with no load (lights off, A/C off etc.).

Mine idles at around 750rpm with everything off, so I think this is normal too. Once the A/C is turned on the engine revs higher, due to the A/C compressor using engine power, to around the 1000rpm mark on the dial. I think modern engines idle so low to reduce fuel use at traffic lights etc. for models without stop/start.

Hope this helps :)
I had the same feeling as you. since I had Micra K11 before. when I start my K13. the engine rattle at idle, especially after running a while. I even changed all the engine mounts ( thankfully it's cheap to source it from China). the rattle getting much better, but still have some light rattle during the idle, and also if you engage the clutch when the car is on the hill.

Mine idles at 1500rpm when the cold start (below 3 degrees). 1000rpm after a few min. after driving idle at 800 rpm.
 
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