first I apologize if this is rehash. I did a Google search with several phrases but didn't really find anything close. I found something similar in a forum for the rav forums, but not definitive.

long post, trying to give as much relevant information as possible.

2007 camry v6 3.5 2gr-fe, 99k miles automatic.

just bought it used from a used car lot who's had it only a few days, decent carfax records. fluids look OK test drives great, few non critical issues that dealership cleans up.

called Toyota service and asked pointed questions about engine, etc. and was assured that maintained engine and car should easily last 300k miles.

5 hour drive from dealer to home, family member following in other car. enroute it starts puffing a little smoke on accelerating, nothing major. stop for a bit and pulling out after it puffs some darkish smoke (NOT black, just sort of darkish) in a pretty good volume. tried accelerating again and less smoke, after a couple of tries it clears up. I think maybe it's just sat a while and needs to clear things out. stop by to see another family member about an hour from home. sit a couple of hours before heading out. on heading out more smoke during accelerating, from idle and from coast, but getting different opinions on color. white, Grey, bluish, slightly sooty, and different shades of smoke at different times. I pull over and have family drive and on phone (hands free) give instructions. they are able to produce smoke 3 times. not quite white, one smells like burnt oil, another smells like burnt rubber, another smells like chemicals that remind me of fuel additives. after family gives info of smoke smells like burnt brakes, burnt rubber, burnt oil (different smells different times)

get home, dealer is closed. turn it off. check fluids next day. oil is considerably low. antifreeze seems to be about what I remember. start up and get whitish (not quite) smoke that clears. turn off. add oil turn on, let warm, and test drive. plenty of power, no hesitating. initially no smoke on any of the previous conditions but after a while it starts again,

then when turning onto the freeway ramp from light it emits a thick cloud, hesitates several times and throws codes then exhibits obvious loss of power. go to the shop. codes random misfire, cylinder 3 misfire, cylinder 5 misfire. leave it on waiting for the lead mechanic to check fuel flows and computer readings on all available sensors. run it through the gears to check power.

turn off, check fluids, all ok, then turn it back on and codes self clear, power is back. runs fine, no smoke, runs great, take it on the freeway for 30 minutes test drive and nothing.

take it to shop let it sit several hours then try again. initially great but after 30 minutes starts blowing smoke on accelerating, clears after a few, comes back after cruise or idle. still had power. take it home, let it sit overnight

this morning, oil looks ok, antifreeze about what I remember no smoke, starts great. runs great during 20 minutes test drive. now waiting for it to cool since the stick doesn't give clear oil reading when hot.

tomorrow we'll compression test Cold. if nothing then test for 30 minutes or until smoking starts, then try to do compression test when engine hot (i hope my welding gear protects against the heat).

we are leaning towards multiple problems. I'm thinking of getting pcv valve and hose to see if it would help at all. wondering how much is from possible sitting at auction, how much might be rings, valves, egr, etc.

I can't say that it's lost any antifreeze but I'm not 100 percent sure. I do believe it's using oil, but again not yet 100 percent sure.

planning to take it to Toyota this week to dx, hoping their mechanics are more versed in this engine.

any suggestions, thoughts, ideas, opinions?

educated opinions/guesses greatly appreciated. please. if anyone knows any good guru(s) that would advise, I'd appreciate that also.

thanks so much.

edit.

I am going to do an oil change, but don't want to spend hundreds of dollars in parts in a tune up if it's going to end up being pistons / valves, etc.

 

Suppose if a bad enough misfire there could be smoke out the exhaust.

What are the codes? Any related to ign coil issues?

 

codes:
random misfire detected (p0300)
cylinder 3 misfire (p0303)
cylinder 5 misfire (p0305)

and the misfires happened once & after the smoke started and most of the time the smoke happens without misfires or codes.

 

Might remove a valve cover and check for engine slugging.