Valve float 2006 GTO
 

I own a 2006 GTO LS2 with 104,000 miles. The car is near mint condition and runs well. I was told I have valve float from around 4,000 RPM to 6,000 RPM. Yes I can feel it nose over. Is this a common problem with high mileage LS2 engines ? If so how much to change out stock springs ?

The mileage would be less of an issue than the years of spring compression. If a car of that age and mileage is in near mint condition, I would guess it has spent a lot of time sitting with some of the springs compressed. If you indeed have valve float, it is a really easy condition to fix, but it will cost a little time and effort to replace all the springs. With all of that being said, I doubt you have valve float. These engines are engineered to last far longer in both time and mileage than what you have described, and the idea that you have valve float at 4000 rpm is stretching the bounds of believability. Whoever told you that is probably a fucking idiot. Post more details of your symptoms.

im probably going to lean more towards not enough fuel. is there a filter or something on the car?

You can always pull a few springs and have their pressures tested. That will tell you if the springs are worn and warrant replacement.

Try this first. Put a mechanical pressure gauge on the fuel rail shcrader valve. It should read 60 lbs at idle and drop to no less 56-58 lbs under WOT. If it drops to say 50 or 40, the motor will roll over above 4000 rpms. There is a fuel filter also. It is in the tank and inside the fuel canister. It is mesh and designed to screen out larger particles. If the pressure drops off, its probably the fuel pump.

Thanks for all your responses. I recently spoke with a very good LS tech. He said he has been having problems when his customers use certain fuels like Shell which I have been using. He suggested that I first burn through that fuel and use either BP or Sunoco for a few tanks of fuel. If the problem still persists he will look at the car for me. Again thanks guys.

You should find a new LS tech.

Yeah, this is lame.

Understatement of the year award has just been taken.