Chrysler 300C & SRT8 Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
Hi guys recently purchased a second hand 5.7 300c, has anyone encounter a puff off bluish smoke on slight acceleration from slowing down? Its very intermittent but if you accelerate a touch more aggresively it blows nothing? If you slowly accelerate it blow blue smoke?
 

·
Registered
Joined
·
418 Posts
First, welcome to the forum. What year is this vehicle? Do you have or can you get your hands on the maintenance history? The Hemi's have notoriously bad Positive Crankcase Ventilation Systems and, they tend to pump an excessive amount of oil/oil and condensation into the intake and then through the combustion tract and out the exhaust. If you haven't yet changed the PCV Valve, start there. While you're at it, pull the intake tube off the throttle body and manually open the throttle body butterfly (engine off of course) and check the back side of it. Chances are real good (especially if it has lots of miles on it) that it'll be badly contaminated with caked on oil. Also, with the butterfly open, take a bright light and shine it back into the intake manifold plenum and check for puddles of oil. If yours is real bad, you'll also have this.

Many folks, including me, have installed "catch cans" in series with the PCV valve (between the valve and the intake manifold) and this catches much of this stuff. It's normally worse in the damp winter months, as the condensation mixes with the oil and makes a slurry type mess that some call "lattes or mayonaise". On both my 5.7's (05 and 06), I can sometimes fill the 4 oz. can in as little as about 800 miles, depending on the dampness and the type of driving I've been doing. Normally, on mine, I'll get between 1/8 and 1/4 in. of oil (in the summer) between 6000 mile synthetic oil change intervals.

Other than that, a couple other things that COULD cause something like you're experiencing are, bad valve seals (rare, unless you have a zillion miles on it), bad rings. Compression and cylinder leak down tests would be in order, if the PCV system is not causing it. What's your fuel economy like and do you have to add oil between change intervals?

Please keep us posted on your findings.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #3
Hi mate, thank you so much for the very helpful info. Its a 2007 with 62,000miles on it, iv ordered a pcv valve to get things started but ill go step by step as youve said and see where it leaves me. Its allready has a catch can installed before i purchased, its just the intermittent puffs on start up and stop start driving the specialists over here are leaning towards valve stem seals but ill try you info first

cheers again ill post my findings
 
1 - 3 of 3 Posts
Top