Running lumpy

[laville1989]

hi guys, got a 54 plate megane 1.9 dCi. When the engine has warmed up she starts to idle quite lumpy. When you are driving it, it is fine, it only lumpy when idleing. Any ideas?

Cheers

[jononfire]

sensors need calibrating? might be running rich or something. it might be nothing. i know my 1.5 dci feels juddery on start up but once driven its fine. maybe drive it hard every now and again to flush the pipes out.

hope this helps,

regards
jonathan

[IainMW]

Do you mean the engine sounds like it's running on 3 cylinder or do you just get a lot of vibration through the car at idle?

This could be a number of things but more info might help the diagnosis. Mileage, service history, any other problems or warning light etc...

It only does it when it's hot? If you raise the revs very slightly (100-200rpm) does is go away?

[joewin1975]

hi, i just bought a 1.5dci a couple of days ago an im having the same problem, it does only go lumpy once warmed up and disappears if you rev ever so slightly, also as you slow down if you take out of gear its fine right up until you come to a complete standstill, im takin back in a couple of days for them to look at so any advice would be good.......

[laville1989]

there just alot of vibration, and yes when u rev it very slightly it goes away. No warning lights, nothing. Just feels like its idleing a bit 2 slow

[davelowe]

Does it idle fine when it is started from cold?

[laville1989]

yep its fine wen started from cold. It only wen its hot

[davelowe]

Mine had a dipping rev at idle problem a while ago, but new oil etc sorted it (never actually stalled).

Have you got decent oil in yours and have you cleaned the crankcase breather tubing? It can get very blocked with waxy deposits.

The temperature related thing is something I'm looking into at the moment. I have weird symptoms when the engine is hot (lack of power). I'm thinking about cleaning the EGR valve and checking the inlet manifold for blockages. I have a hunch there is a lot of crap blocking it.

[wollyd]

Hi all,
I have a 1.5 DCi 100 Megane, it has a similar problem. Starts and idles fine when cold but when warm it is very lumpy at idle and sometimes can be very difficult to start. Otherwise it runs as normal, no loss of power or stalling. Any help or advice much appreciated. Also the gearbox can snatch a bit when coming out of gears. I was going to change the gearbox oil and see if that will help. It's a 2004 model with full service history and 46,000mls.
Cheers.