I have a 94 150 with the 300. Little over a week ago I had my wisdom teeth removed so I was not well enough to drive until today, I went to start it up and I required excessive cranking 10 seconds approx. It took me lightly depressing the gas pedal a few times to get it to start. Once it started it ran really rough bouncing around from 500 to 1200 or so rpms and shaking quite a bit, and then I noticed this cloud of white smoke coming from my tail pipe that cleared up after a min or two but the engine kept running rough and shaking like that for about 3 minutes. I drove it a short distance 1/2 mile shut down for hour or two went back still took alot of cranking and still ran really rough and still shook. but there was no smoke form the tail pipe. Normally this pick up which is my daily driver starts up right away after only a few seconds of cranking. Any ideas or help would be appreciated thank you. Sorry for the long post and poor grammar

 

Check your oil and coolant for signs of the other, and start doing compression checks on all your cylinders. It sounds like you may have a blown head gasket or cracked cylinder head. White smoke is usually coolant, which doesn't belong in the exhaust...

Jason

 

Thank you. I will do that next chance I get. Why am I only seeing this when it sits for a long period?

 

Maybe a small leak and it takes time to get enough to cause smoke... Just thinking out loud here.....

 

Does the smoke smells like there is any burnt oil? if it doesn't, then it's probably just steam, if you're in a relatively humid area, the exhaust will get moist, and from sitting for that long period, the water condensated and accumulated in there. Once you start the engine exhaust heats the water and turns it into steam and that is expelled along with the exhaust, this should stop after a day of driving.

 

Checked the oil and coolant and no sighns of the other in either.

White 97 xlt that makes alot of sense because i am not noticing any change in the antifreeze level since i last checked it, although it will never stay full it just goes down to almost empty and sits there.

Encho i dont think that it is just steam because i have never had this white of smoke before even in the wettest coldest part of winter when what you are describing occurs. But the next time this occurs i will make sure to take note of the smell.

Now if this is a small leak like white 97 xlt mentioned is it something that needs to be replaced or cant it wait?
And is there any ideas on why it ran so rough/shaky, becasue after being run a little bit and then let set for a few hours it is no longer doing that.

 

Cat's can absorb a lot of moisture when they are sitting around. If there's no sign of coolant/oil mixing or coolant loss then I wouldn't worry about that part of your problems.

It seems your rough running is a different problem than the white smoke bit.

 

Okay but i will be defiantly keeping an eye on the oil and Antifreeze.

Is there any ideas on the rough running?

 

I'm all into codes these days, as I just got a 2004 Honda Element that just check engined on me. Any check engine light going on?

 

If coolant is leaking into a cylinder (& maybe a larger amount while you weren't well) it would cause missing & rough running.

 

like someone else already replied, i'm thinking condensation built up in the cat. check everything else and then seafoam it. remember you'll have to change oil after a day or two

 

fordbozo there is no CEL.

Ken Blythen that would make sense why it stopped after running for awhile.

Once i have some free time i will do a compression test to check if it is a head gasket causing this problem with the White smoke and running rough.

 

You need to check for error codes. It sounds like something electronic. That's what I would do first.

 

I forgot, my old chevy used to smoke on start up but it was definitely blue, and almost certainly leaking valve guides. After it warmed up, no problems...