Megane DCI 1.5 Idling Issues

[hedfleiger]

Hi

I have a 1.5dci Megane 55 plate with 76000 miles on the clock. The problem I have is that the idle speed is great when the weather is cold below 5c. the engine idles a little faster and the car seems solid. If i drive the car for a few miles or until the temp gauge get's up to normal, when the car is stationary and idling again, the engine ticks over a lot slower, but the dashboard and car vibrates and the whole car feels like it's wants to fall apart. This will carry on for a few miles or last around 10mins and then the car will idle smooth again.
If i get into the car and the temperature is above 8-10c then the car will start normal, but will idle rough with the vibrations again. this will continue all the way up to normal temp or about 15-20 miles & then again the idle will go smooth again.
Iam wondering if the coolant sensor is faulty? I have had the diagnostics checked and the car is throwing no faults up at all, but the idle speed seems to have a mind of it's own. I have had the EGR valve cleaned and have also used injector cleaner 3 times, and had the injectors checked.
The drivers side mount looks new, and there is little or no movement in the engine. I just want the car to idle smoothly from the push of the start until i turn it off,but when it starts to warm up the engine vibrates the dashboard like an old car and then goes smooth after a long run or time.
Can anyone help or suggest what may be wrong, it is driving me mad!!

[cyclonebri1]

Seems like lots of tickover issues both petrol and diesel just recently, have a quick view

[hedfleiger]

Found out some more on the Idle problem. The car seems to Idle lumpy from the temperature at the moment in the morning at 10 degrees and continues. It seems to me that the car is assuming the temperature from just the air temperature, rather than the actual temperature of the engine.
I think i read in another part of the forum that the coolant sensor reads from both the coolant and the outside temp, maybe the sensor is faulty/dirty and only taking the readings from the outside temp sensor?
Any thoughts anyone!!

[direstraits]

What rpm are we talking about? Anything in the range of 750 (when warm) to 1300 (when very cold) is OK. Vibrations can come from engine mountings.

[hedfleiger]

thanks for replying. The engine seems to be vibrating only at the low rev level around 750 to 800 rpm. when the temp is cold and the rpm is high there is no vibration.
at the low level as soon as i put on the A/C perfect smooth idle. Turn it off it vibrating again. After around 40 mins travel the idle is fine.
Just short trips and when the temperature is warm the engine vibrates.
Any Clues??

[direstraits]

Hydraulic engine mount, alternator pulley, crankshaft pulley. Check yourself or find a mechanic who knows his job.

[hedfleiger]

All Sorted!!! Drivers side engine mount now fitted and it ticks over & drives like new again, Thanks to all the forum people who helped.

[Blade_fireblade]

Think I have same problem, is it easy to see if you have a faulty mount?

[direstraits]

Think I have same problem, is it easy to see if you have a faulty mount?

Very easy. Tha car shakes more than it should on tick over. You can feel it when you hold your hand on the gear lever.

[Blade_fireblade]

Thanks