Smoke upon (cold) hard acceleration...

[HEVEYMETIL]

Morning ladies and gents:

This morning on the way to work, I had a white H3 Hummer up my ass, right as I pulled off of my street. Now, I'm a nice guy and I like to take it easy on my way in, as my job blows. (I don't need anymore stress)

Well, this lady was being a real b***h and so at the light, I decided to smoke her. As I laid into the throttle, I heard the SC spool and everything seemed fine, but as I looked into my rear view, I saw some - and I mean sparse - smoke.

Could it just be that my engine wasn't warmed up enough? (the temp wasn't registering on the gauge at that time) Maybe I pushed some oil thru the seals or coolant?

Let me know, so I can stop worrying.

Thanx

[NegativeOne13]

Year of car? What color of smoke? And how many miles?

[HEVEYMETIL]

2007 GT - 67,000 miles - no other problems, no leaks, etc. Whitish to gray smoke. And very little at that...

(let me cast more doubt by saying it COULD have come from her f***ing Hummer)

[NegativeOne13]

My guess would be water vapor since the car was cold. Oil would be bluish gray, coolant would be white. But '07 with aluminum LIM gasket, and with only 67k I wouldn't be too concerned. If you had white smoke after it was warmed up and such then I'd be a little more concerned. Hell, it could have even been the Hummer.

[HEVEYMETIL]

Thanks for setting my mind at ease. I never considered the water vapor solution - could have been the change from cold to hot in the mufflers causing some condensation to be blown out.

I do seem to lose some oil at every change - but nothing "drips". I'm not too familiar with these engines as far as leak troubleshooting goes. What's the best solution if it gets worse? It is a seals/rings issues or something easier?

[NegativeOne13]

Like how much oil are you loosing? 1/4 quart? 1/2 quart?

[BillBoost37]

GM states that a quart every 3K is acceptable.

The bigger issue here is that your knock sensors don't become active until about 160F. Which means is you had any predetonation etc.. you were unprotected. I'd suggest again doing this often and it sounds like you aren't really the type. But for those that might be..it's out there.

I'd say being cold and asking for all that power, it's either unburned fuel and or vapor etc etc.. Say it's ok until you get other symptoms. Likely it was just cold motor syndrome.

[HEVEYMETIL]

I use less than a quart at every change - I just want to make sure it's "acceptable" lol - apparently GM says so - thanks for that, Bill. (I googled and saw some crazy oil consumption guidelines!)

I know the manual says use only 5W30, but would a heavier weight be acceptable? (esp in this HOT weather). I always use Mobil 1 - and my school of thought was always increase weight with mileage, to a certain extent.

Bill - I'm still learning - I understand what predetonation is, but can you explain how it negatively affects the engine?

Thanks again, guys.

[BillBoost37]

Sure..

Being supercharged your engine is being force fed air via the charger. The programming in the pcm is looking at the boost pressure and fueling accordingly. However since our cars are shipped all over the world to many climates etc. they are generally programmed. Then there's other systems put in place to try and ensure that if low octane fuel, high humidy, hot temps, odd stuff is present that they engine should run and run decently w/o blowing up. This is where hte knock sensors come in. They measure the amount of noise in the engine block. When the level hits a certain amount or noise happens when the pcm doesn't expect it.. the pcm has the programming to retard the timing. This takes away power and helps stop the dectonation issue from happening. This is also part of the system that tells us which cylinder is misfiring. Pretty cool that a sensor can hear and the pcm can interpret which cylinder an issue is happening on.

[HEVEYMETIL]

Awesome - thanks for the 'splainin! I've already learned more here today than I will this whole week at work - schweet.

A bad knock sensor would definitely throw a code, correct?

[BillBoost37]

A bad knock sensor may not throw any codes. Had a local who had a ton of knock. Tried everything to combat it. Decided to pull the motor, heads and had higher modded parts on hand. There was no piston damage. When we had the motor upside down I noticed the knock sensor end was bent. Odd..it's supposed to be straight. Pulled a spare from the parts pile and he's had no knock issues since. No codes.

BTW, realize..I don't know everythign about everything...sometimes...I'm even wrong.

[SlowNA06]

BTW, realize..I don't know everythign about everything...sometimes...I'm even wrong.

Say it ain't so!

I'd stick with the 5W30, personally, unless you live in one of the extremes, but I would look into the oil loss - with such low miles, I'm betting on a leaky rear valve cover gasket. That's a pretty simple fix. I suggest to clean the heck out of your engine bay (look to the detailing sub-forum for hints) and underneath the car, drive it for a day, then check for wet spots.

[HEVEYMETIL]

Bill - thanks for the tips - and that's why I'm here - I def do not know everything, although I try to convince those around me that I do (not always successful)! On the 3.8's how hard is it to check the knock sensor?

Slow - thanks for the tip. In my family we have an expression we use often when it comes to repairs/problems - "try the simplest solution first". I will check around and see what I can find.

[NegativeOne13]

I would stick with 5w30 as well. The 3 years and 60k miles I put on my car, sometimes I would have to add oil, sometimes not. Anywhere from 1/2-3/4 of a quart between fills.