Svinaldo

Hi guys,
I'm at Watkins Glen track with my 2016 Z06. Almost immediately the car goes into some kind of limp mode, with varying amount of power sometimes less that 300 on the dial. Engine light is blinking, but turns off after a while then comes on again.

I checked the ecu codes and it shows P300 Multiple/random misfire. I disconnected/reconnected the battery and tried again, but same issue. Note the temp is ok, it is not overheating.

I'm at the dealer now hoping they can fix it quickly so I can go back on the track, but the mechanic seemed a bit concerned.

Any pointers? Man I was so looking forward to this track event... Wanna get my car back in business!

OnPoint

Check coils and spark plug wires. But I'm sure they'll look for that.

RS4EVA

That's a huge bummer. Sorry to hear about your trouble, I was in the similar boat last weekend. Hopefully you get back out there soon.

Svinaldo

So the shop could not fix it today😢. Apparently it has logged about 300 P300 codes, but there was no way for them to quickly say what is wrong. Could be many things they said, coils, spark plugs or something with the fuel management, eco mode system, etc. They would need to keep the car for some time. And since it seems completely normal on the road, it is hard to say when it is fixed too... Arghhh!

Is there a point to clear the codes, or is that just a log?

RS4EVA

Clearing it might alleviate temporarily, but it sounds like with 300 it would just be a matter of time before it came back. Worth a shot to clear it and see if it does any better.

Svinaldo

I tried again and now I got the p1101 code, which is much more helpful. It means the mass airflow meter reading is out of scale.

I'll take the intake off and see if I find anything. Feeling somewhat more hopeful for the rest of the weekend!

Snorman

Is the car 100% stock?
S.

Svinaldo

Yes, 100% stock.

Snorman

Maybe it's something simple like a ground wire that came loose.
S.

SBC_and_a_stick

We had a car with the same symptoms and Rich fixed it this way on track. Push them in.

dar02081961

Did you recently change the air filter? Or do anything in the area of the filter and intake?

Generally when you see a P0300 (a generic misfire not yet attributed to a particular cylinder) which is not followed by a least one of the P0301 through P0308 defining the specific cylinders that are misfiring, it tell us you have a vacuum leak of some kind.

What have you done in the hood and engine area recently or last?
Think about what and where you could have created a vacuum leak.

The leak will be after the MAF sensor. The P1101 is telling you the airflow measured at the MAF doesn't equal what the engine calculates it to be from the resulting O2 sensor read. In other words you are getting more air than the MAF calculated. You may (if you run the car long enough and the leak is big enough) get a code for lean (P0171 or P0174) as well.

If the leak isn't obvious. Reset the code and drive the car fairly easily for several miles to see if the code returns in this light duty mode. If it does then is likely a vacuum leak. But it could be from a hose or loose connector anywhere in the intake path aft of the MAF all the way to the manifold/supercharger sealing to the block. Its unlikely the manifold/supercharger itself is loose, so hoses or clamps or fittings on top of the engine are the most likely culprit.

If it doesn't code in light duty mode then run it hard like you would on the track. If the codes return after the hard run but the car didn't code in light duty mode.....this means you have a vacuum leak after the MAF and before the throttle body. This is created by a collapse of the plastic intake track under heavy suction when the car is pulling lots of air (Moving large CFM of air). It may spring back under light loads, idle or when the engine isn't running and be almost impossible to detect. Think hand over your home vacuum hose opening and watching the house collapse. As long as the vacuum isn't on the hose looks and is normal.

Regardless check for loose clamps around the throttle body where the plastic intake connects to it. And also check the filter to see if its clogged by paper or debris you sucked up. And look to be sure the air cavity that feeds the Air filter is clear from the front of the car all the way to the filter.

Good luck
Let us know what you find.

Hershey71

sounds like you have a bad load of gas, I had multiple misfires after winter storage. I burned the gas off and with fresh fuel in the tank, I reset the codes and they haven't returned.

Bill Dearborn

Could very well be a bad batch of gas. Where did you get your last full tank before you drove up the hill to the track? Linda's in Montour Falls? I got a couple of cans there a couple of weeks ago and when I put in the car I started having issues with power loss on track. At first we were blaming it on all 4 of my Hoosier tires slipping on the rims and going way out of balance thus causing the knock sensors to pull timing but the mechanic at the dealership thinks it was more likely gad gas.

Bill

LowFlight

Check this first. I had the ground come loose on a CTSV and it caused all kinds of nutty things. Service Ride Control etc....

l2vette

Automatic or manual transmission??

Svinaldo

Hi guys,

An update here:
I found I could add A LOT of coolant to the supercharger cooling circuit. Maybe 3 liters. Where did the coolant go? I took the car out on the track again and it is much better, but still limping occasionally. I probably have not gotten all the air out.

I did change the main radiator several months ago, but never touched the supercharger circuit (sorry for stating it was stock, I did not think of the radiator).

But I thought the main coolant circuit and the supercharger cooling circuit are completely separate. Not true? If they are separate, where did the supercharger coolant go??

Thanks for your help, guys. Much appreciated.

BEZ06

Good question! The two systems are totally separate from each other.

.

sunsalem

It's most likely you have a leak...

Svinaldo

Indeed, the supercharger radiator leaks. Looks to have been hit by a rock.

Will they cover that under warranty you think?

Also, these two codes P300 and P1101 are they "normal" and nothing to worry about, or maybe due to the supercharger overheating? Or should I insist the shop fixes that too?

Man, why don't they have a code for supercharger overheating....?