Ok, so I was driving home from work yesterday and I was behind another Prius at a stop light. When the light turned green everyone started to go and a little way into the intersection the Prius in front of me looked like it emitted a little puff of blue smoke when the ICE kicked in. I can think of two possible reasons this might happen. One if the driver was accelerating hard and the ICE had to strain as soon as it came on. Two that the blast of air from the exhaust pipe caused dust on the road to fly in the air. Nonetheless I was shocked that the Prius would/could emit any noticeable pollution whatsoever. Has anyone else seen this from another Prius. Justin
One possibility......when a gas engine shuts down, the ICE included, a little bit of oil is sucked into the cylinder from around the valve guides and sleeves. This is caused when the ignition stops firing, but the crankshaft is still turning. So, instead of the power stroke creating high pressure and keeping oil out, it actually is forming a partial vacuum because all valves are closed. Consequently, a small amount of oil in the valve train galley is sucked into the cylinder where it remains until the engine is restarted. The oil is then ejected with the first exhaust stroke after the first power stroke.....blue smoke. Smoking is much less obvious with a new car, but it's still there to some degree with each start-up. Please understand that the above possibility is just my SWAG....Scientific Wild-nice person Guess!
<div class='quotetop'>QUOTE(Hytec\";p=\"55262)</div> A fairly successful sales rep once told me that any explination if said with enough conviction and large words will be accepted as fact. You sold me.
it wasn't my silver prius with stickers was it?.. i was punching it. lol. A good amount of cars produce smoke or noticable exhaust when punching it off the line or starting up. I'm not too suprised the prius does. It's only a tiny puff right?
BLUE Smoke! Blue is bad. Are you sure. I have not been behind many Prii off the line. What was the temperature. Details... Details? Do Prii of low miles blow blue smoke? Say it ain't so JO
I've never seen it from a prius. I've seen it on other cars. I've seen a lot of prius lately. Probably close to almost 50 a day. I drive a lot all day though. OOO.. today i was cruising with 2 other prius and an insight on 101.. it was fun. there wa another prius about 400 feet behind us. no smoke from the exhaust.
I meant to get back to this post sooner but as everyone knows PC was down over the weekend. Details: First of all it was cold probably around 50 degrees (some might not think that is cold but here in the Bay Area it is considered to be) It could have been water vapor, but it looked more blue than white and it was only a little puff then no more. I am not sure how old or how many miles it had but it did have license plates if that is any indicator. Who knows maybe even the owner put some funky gas in it?? Oh and V8 it wasn't you though it was a silver Prius. Justin
<div class='quotetop'>QUOTE(hdrygas\";p=\"55335)</div> The smoke will be a light blue if the oil is sucked in around the valve guides during shutdown, then blown out during startup. Also if the blue smoke is due to valve guide bypass, then it will be only a very short puff. If the cause is dirty/stuck piston rings or a broken piston, then the smoke will be a darker blue (partially burnt) and blowing continuously.
i have been behind a Prius and never saw smoke. i followed a friend of mine to Oregon a couple of times. he was driving a Prius also. at 50º it would have to be very high humidity to produce water vapor plus the blue smoke is a giveaway. sounds to me that he may need engine work here. i will have a pretty good chance to check out the smog possibilities of the Prius tommorrow... that is if i remember to look for it.
