gatti-man

I just bough a z06 and drove it back from Kansas City and dropped it off with LG motorsports for a retune. Car drove great. Pick it up from LG car drove great. Stop and get 93 octane gas at a shell station out of Waco and 2 minutes later I notice hesitation on the throttle, popping in the exhaust like you would normally hear on deceleration and white smoke. I was about twenty minutes from work so I just cruised and parked to take some videos to send to Anthony at LG on Monday. I don't think its LGs fault just that I would want them to work on it if something is broken.

Anyone ever had this happen? What could it be? Car idles fine but with white smoke. Hesitates with varying ferocity once you get on the gas, hard starts or won't start. Oil pressure is stable, oil level is stable after 3 hours of driving, car temp is stable and no codes. Is this bad gas? I know that's super rare but I'm stumped.

OliverM5

How hard were you pushing it when it started having issues? Is the coolant level low?

gatti-man

Cruising down the freeway. Maybe an inch and a half of throttle. Car started up just fine after filling up when I arrived at my job twenty minutes later car wouldn't start first 2 attempts. Coolant level is fine. Couldn't check oil yet I had to work. I dropped it off at my house and took my truck back to work.

All LG did was a retune and it drove fine when I picked it up and for two hours until I filled up. Weird.

2k Cobra

We had a similar problem on the Caravan. Thought our 13 GS was going south. Turned out to be "Bad Gas".

If your problem happened after a fill up and your tank was low, ~ 1/4, the new gas could be your problem.

Too much good stuff from LG to be their mistake.

gatti-man

Yeah totally. If it's bad gas idk what to do. It's literally 9/10ths full. I don't want to run it through the Z. I called the shell gas station and the lady manager basically called me a liar and hung up on me.

I'm thinking tow it back to LG and have them drop the gas tank and drain it?

I've never had bad gas before. Either this is a huge coincidence or its bad gas.

Gary '09 C6

I'm not saying this is your problem, but isn't white smoke usually an indication of coolant being burned
due to a failed head-gasket ? (hope not in your case) ...

Mr. Gizmo

Syphon the gas out down as much as you can, then re-top it off with good fuel.

For what its worth , many years ago, my dad filled up his car. The truck delivering the gas, put diesel fuel in the unleaded holding tank at the station. Dad's car ran for about a couple of miles, then started pinging, running rough and belching out a blueish white smoke.
We syphoned the gas and filled it back up.

It was a 1978 grand prix and a few months old when this happened.. It messed up the catalytic converter which the dealer replaced under the 12 month 12k warranty. The station never admitted fault. Otherwise the car was ok and went to 150k miles before he sold it.

gatti-man

True but my coolant level didn't drop. I thought that it would drop substantially being driven for around 30 minutes before I was able to shut it down.

Also it didn't always smoke. It would start then stop even at idle.

gatti-man

Any easy way to siphon out gas without ingesting it?

Meng134

Key is clear tubing. Home depot has it, Once you get it below the fuel level it will run until empty if you get the hose in far enough.

Meng134

Grab a bottle of dry gas/fuel treatment. Gets rid of moisture/condensation.

Gary '09 C6

that is good ! maybe first try a couple of bottles of dry gas as has been suggested...

gatti-man

If I syphon out the bad gas would I still need to do this? I just bought the tubing.

Gary '09 C6

^ It won't hurt anything...it's just a few ounces of either methanol or isopropyl alcohol...
will dissolve any water condensation remaining in the fuel system after the siphoning.

Meng134

I would save the gas and run it through your truck. a little at a time.

gatti-man

Thank you so much for the help. I really appreciate the help. This is freaking me out. Hopefully it's just bad gas.

gatti-man

Checked the oil. Oil is clean. Coolant is clean and full. Had trouble siphoning out the gas. Got like 1 gallon out and that's it. Feels like the tube is hitting something. Getting that dry gas tomorrow and a smaller tube that isn't as curvy so maybe it will be easier.

gatti-man

Ok used the fuel rail and pumped out the gas. Put good gas in and started it up. Barely starts for even a second then dies. I give up. I'm going to trailer it and get it looked at.

Michael_D

White smoke is fuel in an atomized state. Very dangerous. It is caused by having a VERY lean combustion where the air ratio is so high, the fuel air mixture cannot ignite. Check all your plug wires, then carry on with anything that could be causing misfire.

That all assumes it truly is white smoke, and not vapor.

gatti-man

It's definitely white smoke for sure. I did check all connections are secure but that's the end of my knowledge.