white smoke

[copeboyq45]

Hi im new to this site and i have a question.Im a heavy DIY and i just bought a 1994 q45 the guy told me that the only problem was the starter well i put that on and to my suprise the car puts out white smoke. I let it run for about 30 minutes because it was sittin up for about a year but its still smokin not to bad and has a skip.I wanted to know is this signs of a head gasket i dropped the oil and there was no water mixed nor was the coolant mixed with oil i looked under the oil fill cap and its not milky at all. what could it probably be

[loystock]

Is the CEL on? Looks like you have done preliminary checks. Do you smell oil or coolant at the exhaust? If you're lucky, it maybe just water accumulation in the exhaust, especially in the muffler, that's steaming out. Also, at this time of the year cold ambient air tends to condense from hot exhaust gas. Take it to the highway and do some WOTs (but within speed limit) and see if it goes away.

[goody90q45]

....... I let it run for about 30 minutes because it was sittin up for about a year but its still smokin not to bad and has a skip.....

Did the previous owner ever change out a fuel injector? When you restart in the morning does the white exhaust smoke increase for a minute before settling down? It sounds like a leaky lower injector o-ring or an injector failed in the open position. Any condensate in the exhaust should have been gone after 30 minutes.

Tie in to the fuel line past the filter with a pressure gauge and see if the fuel rail is holding pressure. Turn the key to the on position and listen for the fuel pump to run for a few seconds. Turn off the key and see if it holds that pressure, about 35+ psi. If it's bleeding off an oring is leaking.

The skip may be a dead injector or two and maybe plugged injectors after sitting for a year. Ohm test your injectors to see how many are still firing.



http://q45.org/ohminjectors.html

[Skibane]

As loystock mentioned, it could just be condensed water in the exhaust system - a particular problem with Q's. Driving the vehicle for a while should eliminate most of it, particularly if you get the engine above 4000 RPM or so to blow the water out.

If it's a leaking gasket, you'll notice the coolant in the radiator overflow tank slowly dropping - Mark the level on the tank with the engine cold, and then check it every several days for a few weeks to see if the level drops (always checking when the engine is cold).

Sometimes, white smoke is due to oil consumption. It can be worse if the crankcase is overfilled even a little bit - check your dipstick carefully. Also, shutting the engine off immediately after flogging it tends to leave a lot of oil pooled in the heads - which can produce smoke during the next cold start.