Hi, I have a 09 Grand Cherokee, 4.7 L, 125,000 miles. Intermittent problem, but has been doing it since about 40,000 miles. After prolonged highway speed driving (at least 10 miles), and then coming to a full stop at a traffic light, when I go to step on gas to accelerate again, it bogs and bucks and sends blue and whitish smoke out the tailpipe. It does this for about a quarter of a mile - then all good again. This happens maybe 1 out of 20 times that this driving scenario comes up. It has never happened during city driving. Dealer has looked at it - and of course, it never happened to them. No codes showing up either. Any ideas out there? Thanks.

What specifically did the dealer do or test?

Dealer only drove it, and the problem did not happen, so they said nothing they could do. Not much help I'm afraid.

Blue smoke is burning oil. This is just a guess but 2 thoughts come to mind. Pvc valve could be blowing oil into your intake or a leaky valve stem seal.

The pcv is easy to replace, the valve stem is an internal engine part. You should do a compression or leak down test. The dealer should have done that when you had it in there imo.