Opinion on Leon mk4 diesel engine

[idaiosmani]

Hi everyone.

I own Leon mk4 2.0tdi 115hp (manual transimssion). I have some remarks on engine for which i wanted to consult you with

-Often when completely stopped on traffic lights the RPM needle shows exactly 1000rpm, instead 850 or somewhere under 1000rpm.

-When strating the car with clutch only (or slow acceleration) the car engine creates a slight vibration with a rough sound, for which i doubt it to be normal

I have to mention that i mostly drive around city, and least at a highway. Dont know if it has something to do with what I am doubting.

Have any of you experienced this?

 

[SRGTD]

I don’t think there are many mk4 Leon 2.0 diesel owners on the forum.

If most of your driving is town / city driving, then the raised engine RPM’s when the car’s stationary could be an indication that the DPF (diesel particulate filter) is undergoing an active / forced regeneration to burn off soot deposits that’ve accumulated in the DPF. Lots of short journeys / town and city driving will probably mean there’s greater build up of soot in the DPF compared to a car travelling mainly on longer highway journeys, so the frequency of regenerations is likely to be high, especially if the engine doesn’t always get up to optimum operating temperature by the end of the journey.

Are there any other tell-tale signs that are characteristic of a DPF regeneration? - e.g. Stop Start not working, engine cooling fan running continuously, a ‘hot’ smell, worse fuel consumption than normal, a message under the vehicle settings advising you to keep the engine running (I’m not sure if a message is generated during a DPF regeneration in a mk4 Leon).

You may find it beneficial to take your car on a longer highway journey once a week. By doing so, the engine will get up to optimum operating temperature and soot deposits in the DPF should be burned off passively during the journey.

It would also be worth familiarising yourself with the particulate filter section in the owners manual. Here’s a screen shot of the relevant pages from the November 2021 edition below.

With regard to your second question; sorry I’m not able to offer any suggestions.

 

[andylong]

My, albeit elderly, MK2 has a high idle when it's trying to do a dpf regen. Stop start stops but it's rarely smelly or smokey.

 

[andylong]

The second thing sounds clutchy. If doesn't do it in neutral but does with the clutch in and in gear then clutchy.
Exactly what is wrong could be worn clutch or mating faces, dual mass flywheel (why oh why did that happen), if you have one has a finite life so may be the issue.