Trouble Code Question

[Diesel Rookie]

I recently put an older big head waste gate actuator on my turbo when I put in the wicked wheel. My buddy had it lying around. We tested it and it worked. When we installed it we preloaded it 1/8" or 3 turns. It definitely does not blow off like the stock one but you can hear it when you put your foot into it between 2 and 3rd gear.

Today after goofing around and putting it to the floor I got a check engine light. :cursin: The code was P1249 Waste Gate Control Valve Performance. I asked a couple of buddies and they had never heard of it. Is this really bad or just a nusance code? Should I be worried? :yikes2: Any help would be greatly appreciated.

Thanks
Joe

[cleatus12r]

Joe,

It's more of a nuisance code. It's no big deal. It has to do with the PCM commanding wastegate operation but the boost still climbing.

The sound you are hearing during the 2-3 shift is turbo stall. It's not good for the turbo at all. There is a lot of boost in the intake tract when under load at high rpm. When the transmission shifts, the need for all of that boost is diminished slightly and the air has nowhere to go but back out of the turbocharger compressor. You will not hear a wastegate open.

[soutthpaw]

Joe,

It's more of a nuisance code. It's no big deal. It has to do with the PCM commanding wastegate operation but the boost still climbing.

The sound you are hearing during the 2-3 shift is turbo stall. It's not good for the turbo at all. There is a lot of boost in the intake tract when under load at high rpm. When the transmission shifts, the need for all of that boost is diminished slightly and the air has nowhere to go but back out of the turbocharger compressor. You will not hear a wastegate open.
Cody, is that where the torque reduction map comes into play??

[cleatus12r]

Nope. Unfortunately, there's not much one can do about it save for not driving the vehicle under those circumstances.


Any turbocharger will do it given the right operating conditions (like surge), but certain turbos will be more immune to it on certain engines.

It's caused when there is sufficient heat energy to maintain high boost/high compressor speeds and then instantly it's gone (during a shift or "throttle lift").

[Diesel Rookie]

Thanks for the info Cody. I will try to keep my foot out of it as much as possible, as hard as that is going to be.

Just for my own curiosity what kind of damage can that do to the turbo?

[NHRA6002]

On some engines depending on turbo, turbo stall on unloading can damage the compressor wheel. :thumbsdwn:

[ChuckD]

Just put a blow off valve on there.