Car smokes on takeoff after stopping at red light

[scandy001]

I've just rebuilt my engine and have less then 600 miles on it (yay me). It does not smoke at start up and does not smoke while driving but if i stop, like at a red light, when I take of again I get a little puff of white smoke.. I put an egr delete kit on it, could that cause this to happen? Or could it be fuel related?

 

[Thermactor]

Have you considered doing a compression test to eliminate the rings or valve stem seals as being a cause?

 

[Lextreme II]

I've just rebuilt my engine and have less then 600 miles on it (yay me).

What is REBUILT MEAN?

 

[scandy001]

I've considered the compression test but was hoping to try smaller things first. just pulled plugs and #4 had a tiny bit of oil on it. By rebuilt I mean I had it tore down to the last nut and bolt and put it all back together. ACL rods and mains, total seal rings, all new gaskets, I replaced the valve stem seals myself (second set of 1uz heads I've done). This is also the second engine I've rebuilt so I'm some what experienced but by no means do I know it all.

 

[Lextreme II]

Well, replacing the rings was a bad choice unless you over bore your sleeves. Given the age of the motor I am sure it would be not complete round.

 

[cribbj]

You need a 45 degree crosshatch with a particular roughness profile in those cylinder bores to ensure the new rings will seat. If you didn't machine hone those cylinders with the right grade of stone, and on a Sunnen or equal honing machine, I would venture to say that's your problem.

 

[yodathespian87]

White smoke means anti freeze, when you rebuilt did you use new gaskets? If not thats the problem. If you did, is everything torqued correctly? When it was apart did you inspect the cylinder walls? Valve check? Somehow antifreeze is being burned.

 

[zen]

do what???

 

[scandy001]

Well I would have to get back in touch with the machine shop then. I took the block to a pretty reputible machine shop around here but I guess everyone slips every now and then. I'm sure they didn't bore it though. When I tore it down it had a nice crosshatch and when I got it back from the shop it still had a nice crosshatch so I dont know if they even touched it! Yodathespain, the cylinder walls looked fine and I used new gaskets. Got all my torque specs off this site! So I hope they're right. Only ones I couldn't find was Flywheel to crank and flywheel to torque con.

 

[cribbj]

I didn't mean to imply it needed boring, only honing.

After a hundred thousand miles and a few billion strokes, the existing cylinder bores and piston rings have become pretty close friends. When you upset that relationship by introducing a new set of piston rings, you have to get the bores and rings reacquainted and the way to do that is to put a slightly rougher crosshatch on the bores with a hone.

Then you break the motor in to seat the rings, and the best way to do this is by putting load on the motor early on.

 

[spf_lexus]

Cribbj nailed it

Can you describe how your engine was "broken in"? Simply cruising around town at a fixed rpm range is the worst way to break rings in. I would CR test 1st before anything else to help narrow down the issue. It's not like it's that hard, only takes 10 minutes. Local parts stores loan them out.


But like above, it sounds like disgruntled piston rings.

 

[sideshow]

could also be the valve stem seals
maybe one was cut when installing

you see when u slow down engine creates abit fo vacuum so oil is sucked thru the valve stem seals if worn or faulty
then while yr idling a tiny bit of oil fills the cylinder
then when u goto take off this oil is burnt and blown out exhaust
if it was the rings u would get white smoke all the time while u were accelerating
but if its a very slight leak thru the oil rings on the pistons it might cause same thing

but i think it might be more valve stem

but best way to find out is go for a small drive and loa dit up as u get back to home
and engine break alot as u ge tback
this will get alot of oil into cylinder

pull the spark plugs out and look down each cylinder with bore scope
u should be able to see if there is oil in the valves
u might have to turn engine over slowly while looking at valves to get them to crack open abit and so u can see on the stems if there is oil

one thing i might also be by chance is check the power steering idle up valve
once in a blue moon ive seen these leak psteer fliud into manifold

another thing to try is using slightly thicker oil
i used to run 15w40 in my 1uz
i would not go thinner maybe try 20w50 for abit and see if it gets better

another thing to do is find a long sort of steepish hill
put car in 3rd gear and drive up it at half throttle this puts alot of load inside cylinders
and helps t bed rings in if they ar enot quite bed in
do this then drive for abit with no load then do it again
on and off load the rings up afew goes see if it helps

 

[scandy001]

Thanks to everyone for your help. This is extremely aggrivating! My car started just smoking real bad when I was sitting in line at a gas pump. I turned the car off, got gas, started it again and it let out a lot of smoke. smoked for like 10 seconds and just quit again. It's not consistent so that's what's really got me confused. I wish one of you guys lived in MS to come help me lol. I need to hear another 1uz running also to make sure it has the same or similar sounds as mine. Any little noise that I think is different freaks me out!

 

[spf_lexus]

Can you narrow the smoke down to coolant or oil? It would help a lot. If it's oil, it is most likely valve stem seals or a leaky HG oil port. If it's coolant it most likely is a leaky HG's coolant port. Thats why i recommended a CR test, if a particular cylinder isn't right, it will save a lot of time diagnosing.


Try using straight STP or a thick weight oil just to see if the smoke goes away, this would for sure slow down or temporarily eliminate a valve seal leak.

 

[scandy001]

My exhaust doesnt smell like it's burning oil.... It smells funny actually. I will try thicker oil though. I'm praying I don't have to go back into this engine though. I've about run out of patience with this car!! I love it though

 

[spf_lexus]

Burning coolant will have a foul chemical smell and is nothing like burnt oil.

what car is it is in? My LS400 used to smoke after a short time parked, also in the mornings but it was a deferctive power steering pump valve allowed fluid to be sucked through the intake vacuum lines. I was told over and over that it was a valve seal and it never was.

 

[scandy001]

It's a 92 sc400. I bought the car used so I don't know any history about the drivetrain besides what I've done to it. I'm going to do a compression test on it. I pulled all the plugs and none of them had coolant on them. Front plug on the pass side (#4 I think, could be wrong) had a very little bit of oil on it. But it definitely doesn't have a oil burning smell.

 

[scandy001]

Ok, I definitely have water coming out of my exhaust! Is it possible for the IAC valve to leak coolant into my intake manifold??

 

[spf_lexus]

take the manifold off and look. What kind of HG's did you use and what kind of head studs? torque?

 

[scandy001]

I used a graphite head gasket, new head bolts, and I torqued them to 29fp then a 90 degree turn all in the right order of course.