Excessive smoke on tickover
Hi all, new to the forum so please bear with me. I have a 2006 WK Grand Cherokee 3.0 CRD that is my pride and joy. Pulls like a train and goes anywhere. Problem I have is that on tickover after a couple of minutes there is a lot of blue/grey smoke from the exhaust with an awful smell that i cannot describe but it stinks. After moving off and driving a couple of miles it clears but returns again when stuck in traffic jams etc and left to idle for more than a couple of minutes. It does not use any oil or water at all, drives and starts perfectly, pulls like a train, has no miss-fire and does not smoke at any other time. Some people have said it could be valve stem oil seals but it doesn't use any oil and the smell does not seem like burning oil.
Any help greatly appreciated as it can be embarrassing when in a traffic jam or like last night when we were stuck in a multi storey car park queuing to get out, everyone was staring and pointing to the back of my Jeep. As if i didn't know, how could i not see it lol.