I'm stumped

[innerware]

Hey all. My daily driver 78Z pretty much all stock has been smoling for a while now. I can't seem to figure out why and was hoping you all could help. It only smokes apon start up. For the most part in the morning is a definate. It smokes untill the car is warm. Usually stops when the temp guage starts reading some heat. It is a grey/white smoke. And there is a lot of it. The harder I press the throttle the more the smoke. I do not have any sludge in overflow tank. I also don't have any sludge in the oil. None on the guage stick and none around the filler cap. I was thinking it was oil and that I had a leaky valve guide. Then I was thinking it was real rich apon start. It doesn't smell like gas as I have stuck my head in the cloud of vapor and smelled. I also put a rag at the end of the exhast and it fealt damp and didn't really have an odor. I will also notice some liquid drip out onto the ground. But that is fairly common with condensation build up over night. Once the car is warm and it goes away it doesn't come back while driving. Once in a while it will do it if the car sits for 15-20 minutes and then I get back in and start it.

 

I am thinking it is a head gasket. My friend who knows a lot more about cars then I do thinks it isn't. Could I be burning coolant and not see it in the oil and oil in the coolant?

 

Anyway I want to give up, and was hoping for some suggestions. It drives well and no one thinks it is a head gasket.

 

Thanks in advance,

Kyle

[AK-Z]

As most of the people on this forum would say "Do a search." I'm Not like that but do sugest doing so.

 

Well there are some things that I could think of from reading some of the other posts that other people had with the same problem.

 

The liquid comeing out of the tail pipe is normal (inless its coming out in a stream) its just condisation building up inside the exhaust.

One thing that other people over look with this problem is the electical connections, e.i. the computer reading the signal properly. From my understanding the computer goes into "gimp mode" a preset default setting that goes into affect if the computer can't read the proper signals.

 

Other could be that the temp sensor is goint bad.

 

If it is a coolant leak the smoke should smell sweet like maple syrup.

 

O2 sensor could be goin also.

 

I can't think of other things that could be wrong with the engine, but I would check all the spark plugs and see if they ar running rich.

[innerware]

Thanks. Today if my friend remembers to bring it to work we will do a head gasket test (attaches to radiator cap location). I will pull the plugs and see there condition too. The smoke doesn't really have a smell at all. It is just grey/white. I have read pretty much all the posts on this forum too. I am pretty much an addict. Ask my wife. But with all the others it seems a bit different. From what I have read: Blue smoke is oil, grey smoke is fuel and white smoke is coolant. If it is coolant though. Wouldn't It show up in a lack of power and milky nasty oil/coolant? If it was running really rich and the smoke was light grey wouldn't I smell fuel in the exhaust? It's just embarrassing really. It just passed smog. And LT1 who pretested/presmogged it said it looked to be in fine operating condition and didn't think it was a head gasket issue either.

 

Thanks again,

Kyle

[Here comes trouble]

The gray white smoke usually indicates a minute headgasket leak with antifreeze/water causing the smoke on start up.

[datsunlover]

This may sound silly, but is it getting colder lately? Up here it's quite cold in the mornings now (soon to get colder.. stupid winter..) and ANY vehicle apears to 'smoke' for a few minits after startup. (My truck, girlfriends 2002 grand am, anything) A combination of running slightly rich on startup (as all FI vehicles ussualy do; warm up cycle or whatever you call it) and the outside air temp being cold, the exhast is very visable for the first few minits. Some days in the middle of the winter, even after a good warm up, you'll see ALL the cars on the road 'smoking' while sitting at stoplights and whatnot.

[innerware]

It would be nice if that was all it was. But today was almost 80 out and it is usually around 55-60 in the morning. I know a bit of smoke is normal on warm up with cars but this is a bit more than a little.

[SHO-Z]

The white smoke on start up is the one of the products of burning the gas H2O. When the exhaust system is cold the water condenses out of the exhaust until the system heats up.

 

You might want to do a pressure test on your cooling system and see if it holds pressure.

 

I have a gauge set up that plumbers use to test gas systems to test my cooling system.

[AK-Z]

Might be a stupid question, but do you refill your system with coolant or water? the diluted coolant could be what is not letting the smoke have a odder.

 

Whats the humitity down there, could be a factor.

[innerware]

Humididty isn't too high. It's Northrern California. So mostly around 50% I think. Although in the mornings a lot more. Right now it is 93% at 6:40 am. I have been using coolant that is premixed the proper amount. Should I switch to using another type? Thanks for all the suggestions. Everyone rocks!!

[Here comes trouble]

Pay attention to the coolant level. Just a microscopic leak will white smoke. Do the tests to rule out head gasket

[Guest 305240]

To put your mind at rest, do a radaitor pressure test first. Pull the plugs and listen for an air leak. If you can hear one, then you have a bad head gasket. If all is well, put the plugs back in then start the engine. watch the pressure gauge on the tester. If it jumps and climbs that means you are in need of a new head gasket, as it's pumping air into your cooling system. If all is well, do as AK-Z suggested and start checking connections. A little white smoke is normal, but what you are saying leads me to believe it's way too much and something is wrong.