Rough Idle

[Charlsburg]

Hi all, ive got a 53plate 1.9 dci 120 with a rough idle. Un-noticeable when the engines cold, then starts to get rough as it warms up. after about 45mins of driving it starts to smooth out. I was told it could be a lambda sensor, any ideas?

Cheers

[Messer]

Have exactly the same problem (when the car starts!), although it seems a bit more random than yours as it's sometimes there from idle - the amount of visible vibration through the steering wheel when stationary is shocking. Have been told by the stealer that it might be the glow plugs, although we had 2 changed during the course of last year at a cost of £180 to try to solve the very same problem..... Disheartened doesn't even come close.....

[AlexB]

Charlsburg ,
There is no lambda sensor in this engine. Rough idle may be caused by sticking EGR valve. If the cleaning does not help -- record the engine parameters while idling and driving with ELM327 (search ebay for it) and post the diagrams here.

Is your engine remapped, BTW?

[Charlsburg]

Ive just had a full service and all glow plugs changed, i use a tuning box. ive tried without it and still rough but not quite as bad, funny today on the way home with the box still in it was quite smooth all the way. just hope im not doing any damage to the engine. Is cleaning out the EGR valve easy enough to do your self?

cheers

[Charlsburg]

Have exactly the same problem (when the car starts!), although it seems a bit more random than yours as it's sometimes there from idle - the amount of visible vibration through the steering wheel when stationary is shocking. Have been told by the stealer that it might be the glow plugs, although we had 2 changed during the course of last year at a cost of £180 to try to solve the very same problem..... Disheartened doesn't even come close.....

If it was the glow plugs would have thought it would come up with a 'check injection' message on your dash, thats what was displaying on mine.

[pw981]

Sounds like your dual mass flywheel is faulty. Many Renault dealers will go for the fuel injectors as it seems like its a mis fire?

This is what happened to me, they changed my injectors under warranty (2 years ago) which made no difference. I now have no warranty to cover the cost of 8.9 hours labour and a flywheel to fix the fault - about a £1000.

Source: A competent renault dealer technician.

[Charlsburg]

On a short drive last night, its still rough but after 10 minsish stopped at a red light it was rough then all of a sudden went smooth and the engined was warmed up a bit and was fine. But this morning it was rough even after driving for more than 10mins so it seems intermittent, is this sounding more like a stuck EGR valve?

cheers

[pw981]

Charlsburg,

I have exactly the same symptoms. I've had this issue for 56,000 miles now, (started at 40k, im now on 96k) Each time I took it into Renault, they said no fault found as it was random. Finally though I had my injectors changed, at 60,000 miles just before my warranty expired. at 75,000miles I removed the EGR valve myself on my 1.9dCi and it was clean as a whistle, give or take a bit of sludge in the inlet manifold but I hear this is normal. Having cleaned the sludge it made no difference to the idle at all.

I have only found out recently, what the real culprit is!

[Charlsburg]

oh great, well im taking it into a local garage to see if it comes up with any error codes next friday. so it will just be a quick look, so im going to see what they think. What happens then if it is the flywheel? will the car just randomly break down at any time? what other components can be affected as in need to be replaced?

cheers

[AlexB]

How do you know it is true? Does your clutch feel odd?

Charlsburg,

I have exactly the same symptoms. I've had this issue for 56,000 miles now, (started at 40k, im now on 96k) Each time I took it into Renault, they said no fault found as it was random. Finally though I had my injectors changed, at 60,000 miles just before my warranty expired. at 75,000miles I removed the EGR valve myself on my 1.9dCi and it was clean as a whistle, give or take a bit of sludge in the inlet manifold but I hear this is normal. Having cleaned the sludge it made no difference to the idle at all.

I have only found out recently, what the real culprit is!

[pw981]

I do know this is true because the technician I was speaking to told me the symptoms, before I had a chance to tell him.

- the intermittent rough idling almost like a misfire
- usually only detectable in the colder weather, fine in warmer weather until the fault progresses
- the ticking noise whilst idling when cold

As the dealer technician said, many technicians will go for various sensors and/or injectors but this is never the case. In his experience, it has always been the dual mass flywheel. I'm told that since I've been having this problem for 56,000 miles now, even if I were to get it changed I may still not get a smooth idle as my engine mounts have taken the brunt of vibration.

[AlexB]

Interesting -- Thanks.

[AlexB]

"When mine went, I had no problems changing gears. There was a horrible knocking coming from the engine bay when idling or when the clutch was disengaged. Sounded like someone was repeatedly hitting the engine with a hammer at irregular intervals."

"When I had DMF probs with my Octy, the only simpton was the car juddering a lot when slipping the clutch."

Source:
https://briskoda.net/fabia-i/dual-mass-f ... ms/125041/


Not exactly "ticking"...

This is from VOSA regarding Fords:
https://www.vosa.gov.uk/vosa/apps/recall ... 1C004991E6

https://www.eurocarparts.com/forum/topic ... IC_ID=6503
"A typical failure symptom are a deep knocking noise when accellerating and a characteristic shriek when you start up."

It looks like this:
https://www.schaeffler.com/remotemedien/ ... _de_en.pdf

[Charlsburg]

im not having any of those problems, but ive been told it could be diesel waxing. and this problem started over winter and i live on a big hill in wales so it does get very cold up here. but first thing i want to try when i get a chance is clean out the EGR valve, and wait for warmer weather. If it goes then it must have been the diesel waxing up.

[pw981]

AlexB,

I appreciate your research and I agree with you if you think the problem is not the flywheel.

However, as I've had no other advice from this fault - I am therefore led to believe that in my case this is the underlying problem. Every engine is different, and as the Renault Tech said, he has never come across a completely failed flywheel on a 1.9dCi, just a one which is causing lumpy idle and the other symptoms. All these symptoms went away with the replacement of a flywheel.

Saying that though, the Renault tech didn't actually get into my car and "feel" the fault - so he is diagnosing my car from what I'm saying - same as I am diagnosing charlsburgs problem by what he is saying.

Charlesburg, the problem with my car also happened during winter, it went away during summer, then came back in winter. Now it is all year round! Someone suggested to me before that it could be the fuel temperature sensor? AlexB, do you think it could be this? I am still interested in other theories to this problem!

Thanks

Phil