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Hi! Weird White Smoke And Stumbling 5 Mins After Start Up. Help&#3


enksdad

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hi folks! my 93 ls 400 with 173k is the best car ive ever owned and despite a hurdle or two im not willing to give up on it yet. but this issue has me stumped. it starts and runs fine for about five minutes while i let it warm up then it starts puking a white smoke unlike any ive ever seen come from cars. (ive have nearly 30 different cars(and trucks) all toll and am no stranger to vehicles and their emissions) this happened overnight, i've never let it get hot and have always meticulously maintained it. for some reason im thinking its something kinda simple like egr or??? any shining lights would be greatly appreciated! i currently am unable to drive it. although i live in san diego, my motorcycle commute is getting chilly!!

thank you in advance tim

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Spring is coming Tim. Hang in there. The motorcycle commute will get better. ^_^

White smoke is usually coolant leaking into a cylinder. Usually.

So, with it obviously burning something in addition to gasoline, do you notice any of the fluids being low? Check the coolant reservoir. Also check the power steering level.

I would also pull the spark plugs and look very carefully at them all because they often can tell a story. If one or two are exceptionally clean or a coolant type color, you have your answer. If all are the same, then its something other than a head gasket. If you do this test, make sure you mark each plug that comes out so that you can identify the cylinder.

And finally... WELCOME to LOC. :cheers:

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White smoke is caused by the power steering fluid being sucked into the intake. Find the two vacuum hoses attached to the power steering pump. Both go to vacuum connections on engine. Block both hoses and openings and smoke will stop. The issue arises from failure in the parking assist portion ot the PS pump. Extensive coverage of this topic in past.

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Something isn't working right on this website, this is the only way its letting me type something here. can't use carriage return it self wraps. Its okay to remove this post after this problem is fixed. I was going to say ecu caps can cause the white smoke deal too. What does the smoke smell like? If its gas its the ecu I've seen that a few times.

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  • 3 weeks later...

hi guys thanks for all your replies! ive been out of town since my last post(death in family) and havent been able to check into car. i am back now and have done the p.s.vac lines to intake manifold and things didnt change. smoke does smell funny and will check into the actual scent of the smoke today after work. i dont want to believe its a head gasket, (seriously happened overnight) but will pull plugs and check fluids for water in oil and visa versa. theres been no hyrdolock and starts like theres no issue. i love my 400 and if i have to do heads, i will. just hoping theres a simpler solution. will keep you all posted. by the way, i dont know how you middle america/ easterners can handle so much bitter cold! kudos to you! i admit im spoiled here in san diego but it aint cheap livin here!! thanks again for all your help! tim

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I really hope its not a head gasket too, Tim. How do these things happen 'overnight'? Well, sometimes all it takes is a WOT event and bang, gasket gives. Like entering the on ramp to Interstate 5. ^_^

Whatever it is, you should be seeing the fluid level going down drastically. If coolant, the reservoir should be pretty low. Ditto for the PS fluid. I would carefully examine and track those levels.

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hi guys! again thanks for your inputs! am busy getting back into the swing put was able to check fluid levels and colors. all levels are fine even ps and oil was a golden brown not milky grey! will pull spark plugs this weekend as advised. smoke does smell like solvent and fuel rich. fortunately this car is such a cruiser, i rarely have to pin it to access the 5 but im so temped to race the little tuners in my neighborhood!! tim

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  • 2 weeks later...

hi all, finally was able to pull plugs and wallah! i had two middle plugs on drivers side bank black and ugly! all others had the nice light brown tan color as they should. am thinking about sodium silicate. any thoughts? thanks tim

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Yes, I have thoughts on sodium silicate... "icksnay on the silcatesnay" ;-)

Sounds like you may have found a good clue but you have more checking to do before declaring the problem and deciding upon a possible fix.

The next step that I would recommend is a simple compression test on each cylinder. You could do an "active" test where you crank the engine with a gauge plugged in the spark plug hole or a leak-down test where you fill the combustion chamber with compressed air and see how long it takes to leak down to a certain level. Probably easier for you to do the compression test.

No way would I try to seal a leak with that sodium silicate stuff but thats just me.

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