Need help with engine problem

[240Titan]

ok lets see if somone can help me with this, cuz im kinda stumped...most of the time my engine starts right up, but about twice a day or so, when i try to start it, it will start then die immediately, then when i try and start it again it just sits there and turns over letting out a bunch of stinky white smoke outa the exhaust... Then when it gets started, it bogs if u go full throttle, and it goes down to about 100 rpms then jumps back up to like 1200 rpms, still letting out white smoke. normaly my 240 idles at about 600 rpms or so, but when i have this problem it runs at 1200-1400 for a while, then finally it will go down to 600. when its at 600 it doesnt let out the nasty white smoke. I changed the oxygen sensor yesterday, but that didnt help, i was thinking either the fuel pump or the fuel filter, but im not sure yet... anyone know whats going on?

[Kenrik]

White smoke is caused by water and or antifreeze entering the cylinder, and the engine trying to burn it with the fuel. The white smoke is steam. There are special gaskets (head gaskets are the primary gaskets) that keep the antifreeze from entering the cylinder area. The cylinder is where the fuel and air mixture are being compressed and burned. Any amount of antifreeze that enters this area will produce a white steam that will be present at the tailpipe area.

If white smoke is present, check to see if the proper amount of antifreeze is inside the radiator and the overflow bottle. Also check to see if antifreeze has contaminated the engine oil. You can look at the engine oil dipstick, or look at the under side of the engine oil filler cap. If the oil is contaminated with antifreeze, it will have the appearance of a chocolate milkshake. Do not start the engine if the oil is contaminated with antifreeze!!!

[tiger]

Well, burnt oil can look white too.. just look to see if the smoke/steam dissipates... if it lingers around then it is oil, it will smell really funny too. My tubo used to smoke all the time and it would smoke out everyone at the stop light, the only thing that would make it go away is if I revved it up a few times. So whatever you have that is leaking into the combustion chamber builds up over time (in between starts). It's most likely not your fuel filter or pump. You could have bad valve seals that are allowing oil to seep through, or you could have a bad head gasket. Open you radiator cap and start the car (if you can) and look for the rainbow/shiny streaks on the surface... or look for silver chunks(maybe some actual head gasket floating around in there) But when you have smoke coming out of the exhaust... no matter the color... there is definately something wrong with the car. Have you tried checking for codes?

[240Titan]

i doubt it is antifreeze, im leaning more towards oil... although, the white smoke smells like pure high octane gasoline tho, like if i flooded the engine. i just got home for lunch, so i opened my hood to vent out some heat while i wait to add some antifreeze. yesterday i couldnt even see any antifreeze in the radiator when i opened it yet the car stays cool even when idling... im going to talk to my next door neighbor and see if he thinks its oil being burned or not...

[DjPantsSpecR]

thats no good man. My motor also stayed cool when its head was warped, and eventually it was warped so bad that white smoke would come out of the overflow tank as i drove, yet it still always stayed cool.

what you really need to do is 1) not listen to your neighbor most likely2) fill your radiator with coolant and water very full, it helps a lot if you have one of those funnels that sits in your radiator neck, but you wanna keep even the funnel almost full3) fire up the car without the radiator cap off

if its bad, it will coolant will immediately surge out, but it could be the pump causing that turbulence, if you dont know the difference you wont be able to tell so disregard that.air bubbles will start coming to the surface in the funnel, and sometimes they might stop coming for a few minutes but if they come back and keep coming back you might have either a warped head or a blown headgasket, probably the latter.

i remember when i used to do this trying to burp my system coolant would rise to the top of the funnel and continue just pouring out while bubbles surfaced rapidly. mine was bad though, but you may have a similar experience, good luck to ya

[Kenrik]

oil makes a thick nasty smoke when it burns and you can smell it... the fact that you said it smells like fuel makes me think it is a coolant leak because the white smoke would be steam from the superheated coolant and because of the coolant being mixed with the fuel it would not burn 100% and you would be able to smell the gas..

[240Titan]

my next door neighbor was a mechanic for like 20 years... plus he has a 240... he told me to change the fuel filter and if that didnt work he'd look at my fuel pump... i changed the fuel filter and it turns out thats what it was, i dont think it had been changed in a long long time... it was letting out black gas (i guess nasty deposits from the gas tank) and was being restricted. its running perfect now so im a happy camper... thanks guys for your suggestions

[tiger]

well awesome, you fixed it.