New timing belt sound

Hi guys I’ve just my timing belt done on my meg 250, so I had the timing belt done, aux belt water pump dephaser pulley was in good condition so I didn’t bother getting that done..... but anyway long story short since this change my car has a horrible idle sound when warmed up or driving just below 2000rpm, but sounds healthy when the engine is cold. Clueless as to what’s going on so here I am seeking professional help.

 

Well I’ve just phoned the garage and said do you think it’s the dephaser pulley and the guy who I was speaking to said he thinks it’s something to do with the tensioners and not the dephaser pulley. Cars going back in on Monday to have a new timing belt kit fitted so we’ll see what happens from there......

 

I’d also like to add that before I had the belt changed there was no rough idle when the car was warmed or rough sound just below 2000rpm so surely it can’t be the dephaser pulley????