knasman

Went out for a spirited drive yesterday morning, and at some point the car started feeling a little sluggish. I noticed that the boost was climbing slower than usual, and maxed out at around 10-11psi instead of the usual 16-19 (depending on gear). I've had this happen once before, and it was gone next time I drove it. So this time I decided to pull over, shut off the car, and then start it back up. That solved it, boost was back to climbing quickly, and maxing out where it should.

Anyone else seen this? No messages were logged, car didn't complain about anything.

sgroer

Is your water tank full?

knasman

I think so, and there are no messages about it needing to be refilled. Power also feels down more than the 50hp I'd otherwise lose being out of water. For what it's worth, it was a cool morning (high 50s).

JCR-Porsche

Most common cause would be a de-rate due to excessive IAT's. Did you have water in the tank?

JC

GrantG

Yes, losing 6-8psi of boost means much more than 50hp difference...

raclaims

Does the car actually let you know when the distilled water needs to be refilled?

sgroer

Mine gave no warning and was bone dry... open it up and take a look.

knasman

IAT's? There should be water in the tank, it was full when I got it, and I've only done 700 miles so far. Done numerous drives, only had this happen twice so far.

knasman

Felt positively sluggish, relatively speaking ;-)

JCR-Porsche

Intake Air Temperatures. Its normal that the car would de-rate under extreme conditions by pulling boost and timing. I would check the tank to be sure, they drink that water very quickly when pushing along especially when the ambient temps are high.

JC

knasman

Huh, I'll take a look, I think I saw somewhere else that it throws a message when it's time to add water. I might be wrong...

In any case, don't think that's it, as it felt almost limpy in how it built pressure. Given the fairly low temperature, seems unlikely. I do drive at 6500-7100' of altitude, so maybe...

knasman

Thanks for the replies guys, looks like most folks are placing their bets on the water being used up. I'll take a look when I get home in a few hours!

GrantG

It's really difficult to find pump fuel with more than 91 octane in Colorado. Same in Utah? A bit of unleaded race gas mixed in the tank might make a difference with your car.

knasman

Oh yes, same here, I'm running 91 octane in it. Good point. If there's plenty of water in the tank, I'll have to try mixing in some higher octane race gas.

Polarcharger

91 octane is plenty high at elevation of 6500+ ft.